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Discussion Starter #201
New Boring bar table
Most of you readers are hooked on one kind of cycle or another. I’ve been stuck on one kind of machine tool or another; where we all meet in the middle is the power plant. The common denominator is the cylinder in that little old gasoline engine.
Recently I’ve been improving on my cylinder boring stands. The newest model is 20” deep by 60” long. This new model is 1-3/4” thick, ¼” thicker than the smaller ones used in my shop. It’s easier to slide around the 150 pound boring machines without as much worry of pushing one off on the floor or a foot in the way. As you all have made cycle friendships; I’ve got many friends in the machine shop & fabricating business. My Portland Oregon area is large enough that we have many small & large companies in different kinds of machine & metal cutting businesses. The new boring table stand needed a substantial amount of Water Jet cutting. One of our acquaintances is equipped with just the machine that we needed. The table was still a rather spendy item; $700 for the metal cut to size & another $300 for surface grinding the top & bottom sides. $100 for the lengths of 2” square tube for the base.

The new table will hold 3 machines with ease & plenty of room for tools & such

Weight is around 500 lbs so handling with the fork lift is necessary

We are using 3 Kwik Way machines on this particular table with a 4”wide slot for boring multi cylinder blocks & an assortment of smaller round holes for single cylinders.
The base is the same height as earlier models so I can work with while sitting & taking it easy on my bad back.


The new table has nearly full length ½” slots for sliding the hold down’s back & forth


Vincent is on the Fork Lift moving the table across the shop


Out the loading door & into the cylinder boring room



Off & running; left side is our largest machine, Kwik Way #FN, 2-3/4” & up. Center; Kwik Way #FW 2-1/4” & up. Right side; Kwik Way #FWS 1-3/4” & up.



First job; CR500 cylinder, plenty of room to slide around for positioning

We have an extra FWS machine which will be mounted on one of the smaller stands for sale. The other small stand is in Shop #2 (the garage at the house); this is where I can work on the weekends with no interruptions.
 

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Discussion Starter #202
Mounting cyliders on your 3 jaw chuck

Using your 3 jaw chuck to mount your cylinder

Did you ever have a need to mount a cylinder to clean a top or bottom gasket surface
This is a technique which we occasionally use when a center & mandrel are in the way.
We first need an extra set of jaws; the jaws are mounted on the chuck & clamped as usual.

With this particular application 3, 1” round rods were welded to the extra set of jaws


The problem with my idea is that a 2” 125cc cylinder was too small to fit over the 3 extended jaws. Next was the problem of accurately machining the jaws to accept the 2” bore cylinder. The jaws needed to be expanded & machined under load to be accurate.

I scrounged a length of ¼” brass rod which could be any ¼” rod; also a small cut of round tube. Brad drilled a ¼” hole in each chuck jaw.

After the 3 holes were drilled the 1” pieces of brass rod were inserted.



Finally I slipped the piece of tube over the 3 brass rods & opened the chuck lightly to put a load on the jaws.

With the load on the jaws, they can be accurately machined down until the 125cc KTM cylinder fits over.

The 125cc KTM cylinder is counter bored on the upper end of the cylinder which makes things tricky when a new sleeve is installed.

After we slide the cylinder on the jaws, a pipe center is bumped from the tail stock to ensure concentricity of the cylinder.




It’s easy to do the counter boring operation with the tailstock side of the cylinder clear of obstructions.




The base is accurately trimmed

Your questions & comments are more than welcomed; we all learn together.


John Tice
503-593-2908 Alternate 541-508-3944
www.smallenginemachineworks.com & www.nwsleeve.com
Turning Custom Cylinder Sleeves Since 1971
http://forums.everything2stroke.com/threads/49513-How-It-s-Done-Projects-around-the-Shop.com


:Cheers:
 

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Discussion Starter #204
Kev; keep sending your ideas, you’re our UK connection. We all learn together, what’s new on your side of the pond?
 

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John, been busy with the new workshop, not long to go now almost done. I am just converting my new lathe to run on inverter drive then I can get it up and running because I have a barrel to re-sleeve. All my machinery and tooling/shelving are now in place just need to do the wiring and sockets then hope to continue with the projects and the forum.
Thanks.

Lathemad Kev.
 

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most all 125 engines that im aware of have used plating forever with pretty much only one piston size available. what do you do if they burn down the topend ?
 

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John, apart from anything else, you give us the best photography of machine tool set-up that I've ever seen. Wonderful stuff!!!

Now, I don't want to side-track this from cylinder boring for too long, but here's a different machining subject, a different question about "how you do it in 2015" or even 2016. Some guys were talking about crankshaft work, either making custom cranks (all this is 2-stroke) or changing the stroke of existing full-circle cranks by making a new crankpin hole, and of course this runs into various ideas on the amount of interference fit, of re-balancing (incl. with use of Mallory Metal, etc.), and attendant ramifications. One assertion caught my attention: that nowdays a more accurate job of making the pin holes in a crank throw can be done by a CNC EDM than by grinding to size. As the most amateurish of amateur machine tool owners and users, my only experience of EDM "machining" came maybe forty five years ago, in a community college class that had an EDM rig set up on a Bridgeport mill, which I used to burn out the center of a broken tap.

I am looking at a very old 2-stroke racing outboard crank and musing on possibly de-stroking it slightly. Factory stroke is 54mm; the crankpin is a rather inelegant stepped thing, 20mm where the bearings run, and 18mm where it presses into the crank. This was a 250cc twin (if you are amazed at the tiny size of the crankpin, consider that that the engine started at 25hp on methanol in 1957 when Dieter Konig introduced it, and be further amazed that the best tuner of the final version of the engine was pulling 67hp from the same spindly little crankshaft twenty years on).

Anyhow, long ago I made a pair of unstopped 20mm pins for my motor out of 8620, pack-hardened and centerless-ground (the factory stepped pins would occasionally break). But I never did use these, never did get the factory 18mm holes ground out to take my straight 20mm pins.

So now I have this old croc of a 250 motor, and can envision the possibility of sleeving it down to fit a new 175cc outboard class, which would leave room for drastically upgrading the transfers and ports. Long project, resulting in an engine that probably still wouldn't run with the modern motors, but the old guys would love it. Even with modern ports, the scrawny little crank should hold up since the pistons would be a lot smaller than before.

And I still have my straight crankpins. If I get the holes in the crank enlarged to take these pins, I can reduce the stroke at the same time. Not enough to again have a "square" bore-stroke ratio (which has been oversold, IMHO) but not so under-square as if I leave the stroke alone.

SOOOOooo, John, at the end of this long description, LOL, my question is about that idea of machining or RE-machining crankpin holes via a programmable EDM as opposed to grinding-to-size, the question being, what do YOU think??
 

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Discussion Starter #208

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Discussion Starter #209
Let’s back up a page or so & talk about skirt clearances. There is a lot to think about in piston fits, Plate or sleeve. First; it’s commonly thought that a plated cylinder dissipates heat much better; therefore the plated cylinder uses a much tighter cylinder skirt clearance. It’s time to back up another page or so & consider how tight the sleeve is fit into your aluminum cylinder? LA sleeve & Advanced Cylinder Sleeve companies both tell how tight the new sleeve needs to fit, true enough but how is the sleeve fit in your aluminum cylinder?
If you take your top end to your favorite “Hot Shoe” racing cycle shop & have them fit a new ported sleeve; how is your new sleeve fit to your cylinder, knowing how tight is only the start.

At times a cylinder which has been sleeved by others comes to us for repairs. The sleeve was manufactured by one of the previous mentioned companies. The Sleeve was beautifully produced but had a Bum fit. This conversation has nothing to do with the manufacturers mentioned.



This is what our customer got from another “Hot Shoe” rebuilder & tuner. I suspect that the shop knew that the fit was incorrect but was helpless for a repair solution.

Fitting a sleeve is much like fitting a piston; the final honed fit must be precise.

A CR500 Honda cylinder waiting for the new sleeve.

After the precise honed fit has been produced; the press fit which has been previously determined needs to be reconsidered. The sleeve fit helps determine the final piston skirt clearance.

An accurate dial bore gauge is a must in every engine builder’s tool box
The key to this precision fitting business is the coefficient of linier expansion of cast iron & aluminum. When heated to higher temperatures, aluminum expands significantly more than does cast iron. We use 500 degrees for our elevated temperature to insert cylinder sleeves. It’s highly recommended that the machinist measure both the aluminum cylinder & iron sleeve at room temperature & 500 deg. This is the key to figuring the new sleeve’s shrink or press fits. In our shop we use a -.002” for 125’s & smaller, -.003” for 250’s & -.004” for 500cc cylinders. It’s highly recommended that temperature & size measurements are periodically taken. In the process of doing cylinder liner installations; I’ve found that Honda & Yamaha periodically fit sleeves from -.001” to -.0015” press fits. With these looser fits the stock OEM liners can usually be pressed in & out at room temperatures.

How do we fit our sleeve installations? We first ruff bore a plated cylinder +.250” larger than the std. bore diameter. This will net the final sleeve thickness of 1mm after the cylinder has been over bored another 2mm oversize. The final sleeve thickness is rather thin but necessary to ensure proper function of any power valve installations. This is the general oversize of sleeve in a 2 stroke bore; we’ve got an Excel spread sheet programmed to produce bore consistency.
Next the new cylinder sleeve is ruff turned to +.010” larger than the aluminum cylinder. With the new sleeve +.010” larger than your cylinder bore; the aluminum cylinder is finally precession honed to the new sleeve press fit. I use this system of fitting the new sleeve as it helps greatly if making a mistake fit.
With all of these dimensions flying around in every direction; it’s necessary for the engine builder to have a thorough knowledge of arithmetic & geometry. Have a few hand calculators in your shop for handy instant access. Remember that 4”/ .03937 = 101.6mm, the conversion factor from inches to millimeters.

After the cylinder is heated, the new sleeve is lowered & alined. A light press is applied to the top of the sleeve to make sure it’s bedded in place.



After the final bore is completed, off to the cylinder hone. We use a Sunnen connecting rod hone as it gives the best control of cylinder sizing. Yes; you need the proper piston skirt clearance, but as of the clearance the cylinder must also be round & straight. Squaring with the bore is best accomplished by mounting a cylinder upside down. (More on this in other sections)
I use a double stone three point connecting rod mandrel for cylinders under 2-1/2” in bore diameter. Above 2-1/2” a double stone “AN” type of mandrel is used. Both of these mandrels render a smooth round & straight bore when used by a skilled operator.


Large hone type “AN” head for bores larger tan 2-1/2”


Smaller 3 point mandrel used for cylinders less than 2-1/2”.
You may notice the cylinder hanging by a couple of Bungee cords. With my bad back as many of us suffer from; the cylinders are hanging from the ceiling which enables the cylinder to be flipped from end to end, taper control & easy measurements.
(Other types of honing equipment are noted in another section.)

Back to the Skirt clearances; I use the resources of Wiesco piston who has a cycle engine mounted on a Dyno for testing skirt clearances. Wiesco claims that their forged pistons are machined in such a manner that they need barely more than a zero skirt clearance to run without seizing. Granted this is only for testing purposes.
I’ve found that the recommended skirt clearances which are printed on each Wiesco piston box; works fine for most cast & forged 2 stroke pistons. With the very short skirts on late model 4 stroke engines, it’s wise to contact the particular piston manufacturer for clearance advice. Now days both types of pistons are machined to run minimal skirt clearances. After the honing is complete the ports are deburred & the cylinder is rinsed in the parts washer. The measuring tools are rechecked for accuracy; the skirt clearance is double checked, the piston is fit, top & bottom of the cylinder. Any discrepancy in accuracy can be corrected before the job is delivered.
Cast or forged pistons; sleeved or plated bores, when we hone the final skirt clearance; I most always add +.0005” to the recommended fits. With this slight addition to the clearance; I maintain that both types of cylinders each have close to the same heat dissipation rate.
You’re comments & criticism is more than welcome; we all learn together.

John Tice
503-593-2908 Alternate 541-508-3944
www.smallenginemachineworks.com & www.nwsleeve.com
Turning Custom Cylinder Sleeves Since 1971
http://forums.everything2stroke.com/threads/
 

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Discussion Starter #210 (Edited)
Start a new career

“How it’s Done” Can be the start of a new career for those who read the thread. We need new blood in the cylinder & machine shop area. I’ll help you get started at no cost; We spend hours on the evening phone tutoring new & prospective students. Whether setting up new equipment or learning how to operate your cylinder boring machine. Give me a call most any evening until 9pm pacific.


John Tice
503-593-2908 Alternate 541-508-3944
www.smallenginemachineworks.com & www.nwsleeve.com
Turning Custom Cylinder Sleeves Since 1971
http://forums.everything2stroke.com/threads/49513-How-It-s-Done-Projects-around-the-Shop.com
 

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jon on average what does it take to bore a cylinder .010" or so and chop .020" off the top deck. 30-45min ? I ask because my cylinder has been at a shop going on 3mon and im getting a bit ticked off its taking so long. if I haven't heard anything by end of next week im calling the guy and saying get his lazy ass in gear or send my stuff back and ill have someone else do it. I realized why shops are so bogged down. theyre forced to deal with piddly crap like oil changes and top end rebuilds because the unlearned people of today refuse to buy even a screwdriver and do some of the work their self. I know for years you've been preaching folks should learn to do some work their self but im afraid its to no avail
 

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Discussion Starter #212
This sounds like my liner work back up; I’ve got more than a few angry with my slowness. For boring cylinders; we give them first priority since most folks wish to go riding over the weekend. Depending on more than a few variables it can take more than an hour for a round & straight cylinder bore & hone. I’d suspect that if your bore work is taking so long; either the shops priorities are all mixed up or they aren’t properly equipped to do your work?

Removing .020” off the top of the cylinder; 20 minutes, tops with the correct equipment. As we all know; the tops & bottoms of the cylinder need to be square with the bore, no exceptions.

The key here are expanding mandrels


Machining tops& bottoms of cylinders is a minor job with the correct tooling.


This program is still Screwed UP?
 

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Discussion Starter #214
07/23/16 How it’s done
The last few months I’ve been doing a catch up on our work load. For you people who I’ve been dragging my feet, I apologize for being so slow. Since my last entry to this thread; we received a 6 month supply of cylinder repairs in around 2 weeks. It’s taken me since last January to catch up.

My intent for this thread has always been to encourage others to get involved in the cylinder repair business. I have at this time only a couple of people in any kind of a training program. This is a FREE service for any of you who would be interested. Send me an email or give me an evening call (pacific time) & we can talk about it. There is good money to be made for the right person & I’ll help you get started.

We are continuing to receive some interesting repairs which I’ll continue to share with all of you.
A man from Arkansas sent in a V-6 outboard block to replace 1 cylinder sleeve. Unfortunately the shipping is costing as much as the repair itself. Our standard procedure for port marking 2 stroke cylinders is an etch with nitric acid. Since nitric acid attacks any kind of iron material, I was unable to mark the port locations in the standard way. With most outboard cylinders we mark the port locations with a paper trace. The trace is a rather delicate operation but with steady hands the results turn out quite nicely.
With most outboard blocks it’s necessary to fashion a torque plate to clamp the engine to the cylinder boring stand.



With a close look you can see the C-clamps holding the block to the boring stand



We take very light cuts on the sleeve to be replaced until it becomes paper thin & is easily removed with a pair of pliers.


With a light hand the ports have been marked on scratch paper. The ports are machined on the vertical mill as all of our 2 stroke ports are machined.

The new sleeve is fit with a shrink fit the same as any other 2 stroke liner. We always heat the block to over 200 degrees to check its particular expansion rate. There is only one chance to align the ports properly before the temperature equalizes between the cylinder & new sleeve.


The new sleeve is bored to standard & surfaced for a tight head gasket fit.


Another project was a couple of Ariel square four cylinder blocks. The left one is cast iron & the right one is aluminum with iron sleeves.
With the iron block the straight sleeves are fit with a -.001” press fit. The aluminum block was fit with flanged sleeves & a -.003” shrink fit. Unfortunately the heavy 35lb. iron block was bumped & a portion of one of the fins was broken off. We TIG welded it back on with silver solder; our customer was not at all happy with the repair, these things happen on occasion.


The Ariel block being finish honed on our vertical machine


Another repair is with a slipped sleeve in a 125cc cylinder.

Whoever installed this new liner really botched the job. We always bore & hone a cylinder before the new sleeve is turned. The fit of your new sleeve is as important as the piston’s skirt clearance.






We started this repair by mounting the cylinder in the Kwik Way & boring out the sleeve. The sleeve started to spin & jammed up the cutter. The cylinder has been honed round & straight; we’ll turn a new sleeve next week.

A KX500 Kawasaki was sleeved last week


The KX500 has unusual exhaust porting



Not all of the big bore 4 stroke engines have a press or shrink fit liner


This particular cylinder has a large non slip ring around the center. A rather tricky one to hone, well suited for our power vertical machine.





Our custom made cylinder sleeves are all machined on our manual machining equipment





An accurate set of expanding mandrels is the key to concentric cylinder liners



A surface plate & height gauge is handy while machining new cylinder liners.


John Tice
503-593-2908 Alternate 541-508-3944
www.smallenginemachineworks.com & www.nwsleeve.com
Turning Custom Cylinder Sleeves Since 1971
http://forums.everything2stroke.com/threads/49513-How-It-s-Done-Projects-around-the-Shop.com

 

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excellent work JT same about the fin but sometimes things happen that we cant control, seems to happen to me when the work load is very heavy then it makes it ten times worse. I am just fitting two crane hoist in my workshop to help lifting heavy items in my old age LOL, then just finishing the newer lathe electrics then hope to get back to the cylinder work which is why I improved the workshop.
Good to see you are busy please keep up the postings.
P.S, someone I know over this side marks his ports using dyken blue, think he pours it into the ports then lets it dry before reheating and dropping the liner back out, not has good as your acid etch but maybe better then tracing the ports, who knows I will have to try it one day.
Lathemad Kev.
 

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Discussion Starter #216
The acid etch method is far & away my superior method. The problem with OB loop scavenged blocks is that the blank sleeve is not removable. A traced pattern is the only way unless some of you have a better idea?
 

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Discussion Starter #217
Is it time to get on board?

How it’s done; 09-01-16
It’s been a while since I’ve written in this thread. We’ve been very busy this summer.
The picture taking has been continual & random so I’ll write about what comes up next.
We started with the Ariel square 4 in the last entry so there isn’t much in order.
There was a cast iron block & an aluminum block to install sleeves in each of 4 cylinders. The aluminum block had the usual flanged sleeves & the iron block had a -.001” cold pressed sleeves.

The BZM50 Cylinder
We got this one in to work on last week; no instructions& no email return address. Since we are in the sleeve manufacturing business we started to install a new sleeve. Later on when we were around ½ finished with the new sleeve install, the customer gave me a call to see how the project was coming along. What they wanted was a big bore prep for another hard plating job. In my attempt to deliver on a timely basis, we went the wrong direction.
As is usually thought the customer was under the assumption that a plated cylinder dissipates heat much faster than a sleeved cylinder. If the sleeve is properly installed with a good tight fit there’s little difference in heat dissipation. How do I know? I only give the cylinder an extra .0005” clearance to be sure. We’ve never had a seizure from too tight of a skirt clearance.

This little guy was such a small bore that machining down a special Sunnen hone mandrel was necessary.







This very small cylinder was bored on our old & tired Kwik-Way Colt boring bar.

This little machine bores as small as a 35mm , 1-3/8” cylinder diameter


If you look closely you can see the advanced 3 port exhaust port arrangement.



This particular type of cylinder responds quite well to tuned exhausts’

This cylinder could have problems in that just below the exhaust port there is a hole between the cooling fins.



The cylinder is bored to accept the new cylinder sleeve.
If you look back a few pages in the thread you can see how you can bore a small cylinder like this one on most any shop lathe.

The new sleeve blank has been roughed out, porting & polishing is finished





The finished cylinder was shipped off to the customer





I’m attempting to get more people involved in the cylinder repair business. Anybody with a machine shop background can get into this trade with a minimal amount of training. My 68th birthday is on the 6th this week. Someday I’ll retire & there won’t be many left to do the work. As long as I’m around & breathing; I’m available for free training on the phone.
You’ll not see the reciprocating engines go away for at least another hundred years or so. Never assume that plated cylinders will do away with the needs of repairs.


My 3 large Kwik-Way machines are used daily in my shop

I’ve also got 2 more of the smaller Kwik-Way machines in my garage at home. Many times I’ll take a long weekend away from the shop; still doing some more cylinder repairs at home.




My new Lagun FT1 vertical mill purchased some 40 years ago


Every cylinder repair shop must have good honing equipment. A good used Sunnen hand held unit can be found on Craig’s list for around $175.00.


Sunnen con rod hones can be purchased used for less than $2 grand. With a set up like this you will be turning out round & straight cylinder bores every time after time.

Now days a few hundred $s will get you a set of mandrels for turning sleeves on your lathe


HF lazer temp gauge, weed burner & 20ton press


All hints to help you get started

John Tice
503-593-2908 Alternate 541-508-3944
www.smallenginemachineworks.com & www.nwsleeve.com
Turning Custom Cylinder Sleeves Since 1971
http://forums.everything2stroke.com/threads/49513-How-It-s-Done-Projects-around-the-Shop.com


 

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Discussion Starter #218
My 2 stroke cylinder business is as busy as ever. Most of the customers have 2stroke questions & I try to steer them towards E2S. E2S may be having a slow period because of Who Knows What? I can say that the interest is still out there. I’m seeing quite a bit of activity in the 50cc engines, I think mostly because there are few people around who can service these small cylinders. Another reason to buy a Sunnen rod hone & hang up a shingle. I can’t figure out why such a lack of interest in the cylinder business? When I must shut down for a while until my work load gets caught up, some people are unable to get their cylinders re lined. Come on out there, give me a call & I’ll help you get started.
JT
 

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Hi guys, sorry but still busy with my new workshop build,(making more room for sleeve business) everything has taken longer then I was planning but I am getting close, just in the middle of building the second crane then hope to restart the liner work.
I have done a couple of re-bores and hones for my shop customers but looking forward to learning the sleeve business more, I have been interested in automotive machining for years which is why my workshop had been laid out for boring and honing, milling and lathe work. I am still very keen to learn more and welcome any help JT can offer, this would be an opportunity not to mist and not to be taken for granted, JT is a very busy man but he is still finding the time to pass on he vast experience.
Keep up the good work John, we are still out there.

Lathemad Kev.
 

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Discussion Starter #220
Good morning Kev; you are a breath of fresh air to me. I’ve been wondering how you’ve been doing. I’m also going through a big change at the moment. I’m taking all of my cylinder machinery away from the family business location & moving into my oversized garage. The pictures of the move will start to follow.

I purchased another vertical mill from HF. This is the model with the tilting head & adjustable knee. I must say that this is a rather robust little machine. We are finishing the stand this morning so I can operate it while sitting down. For those of you who are new to this thread; I have Multiple Sclerosis & am on crutches 24/7. My balance is shot & I need a walker while in my shop. If I can move ahead so can most anyone else with a disability.
The problem at hand is stuffing everything into the double garage.

On a side bar; if any of you are thinking of getting involved in this work, Beware of the Acids. Acid is the most dangerous liquid you will ever be involved with. I burned both of my knees last week. I won’t go into the STUPID part of this.

Kev is starting to open a wonderful opportunity for himself & the small engine community. As the word gets around, Kev will quickly have more work than he can deal with.

JT
 
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