new to 85-86 lt's need help

5684 Views 32 Replies 7 Participants Last post by NYJOER69, 1 mo ago

winkdogg

Discussion Starter · Sep 18, 2014

i have several lt250r's(87 and up) but i just got an 85...and so the saga begins . i got it for $350 complete but not runing so not a bad deal . flushed rad , cleaned tank and carb , changed oil. its got big fat blue spark and good compression 165-170lbs but coolant is finding its way into the cylinder

i ordered a Tusk gasket set hoping its just the head gasket (i know they can be a pain in the butt) . my question is since there is no coolant in the oil is there a good chance its the gasket and not a cracked cylinder? should i pull the jug to inspect since im getting a new base gasket with the kit or should i just try the head gasket with the copper spray sealant first ? if the jug is cracked will it be obvious and easy to see or could it be microscopic or hidden ? When i kick it over with the plug out a fine mist comes out of the plug hole even with the carb off so i know its not gas flooding it it must be coolant . any tips about the pain in the butt head gasket would be great . i will check everything with a straight edge on all the contact surfaces and shave or deck it if need be . thanks in advance for any help i appreciate it , and will return the favor if anyone needs help with 87 and up lt's! Thanks Winkdogg

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John Tice

· #2 · Sep 19, 2014

You might hold a match over the plug hole when you kick it over to double check whether it’s gas or not.
You also might try to retorque the head studs to see if you have any stripped threads.
Suzuki cylinders have a rather robust iron sleeve, I’ve never seen one with a crack which would cause a coolant leak
Somebody else may have some other ideas.

winkdogg

Discussion Starter · #3 · Sep 20, 2014

John Tice said:
You might hold a match over the plug hole when you kick it over to double check whether it’s gas or not.
You also might try to retorque the head studs to see if you have any stripped threads.
Suzuki cylinders have a rather robust iron sleeve, I’ve never seen one with a crack which would cause a coolant leak
Somebody else may have some other ideas.

I held a lighter over it and it sucked in the flame then blew it out but no ignition . on one kick i got a lil pop out of it with the lighter but i have the carb completely removed so there shouldnt be any gas to get into the cylinder and after 40-50 kicks im still getting the same mist and if i get it on my hand it wont ignite so i think its coolant ... i put a dry new plug in with a shot of starting fluid and still not even trying to fire :?? im baffeled any ideas welcome! thx Winkdogg

mgty3whlr

· #4 · Sep 20, 2014

On the 85-86, it is extremely easy to pull the top end because there is no power valve to deal with.

Most likely, it blew a head gasket because the previous owner probably ran it low on coolant and overheated it.

The water pump might have been leaking, radiator, etc.

I would pull the head first and check the gasket, then work your way down to the base gasket.

These engines are rather simple.

Joe

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John Tice

· #5 · Sep 20, 2014

mgty3whlr said:
On the 85-86, it is extremely easy to pull the top end because there is no power valve to deal with.

Most likely, it blew a head gasket because the previous owner probably ran it low on coolant and overheated it.

The water pump might have been leaking, radiator, etc.

I would pull the head first and check the gasket, then work your way down to the base gasket.

These engines are rather simple.

Joe

Hi Guy’s; I need your help unscrambling these 2 different LT250 cylinders.
Is this correct? 85-86 larger bore, larger reed; 87-92 smaller bore, smaller reed. The 2 on the bench both have power valves. Do they each have the same stroke??

Both years will take a 72mm bore so what might be the best choice for a performance engine? We also need to know, how large can we bore the cases for the larger diameter sleeve.

Over time I’ve read threads about these 2 years plus head stud problems. As I work on many LT250 cylinders I’ve never paid any attention to which is which. Now that I’ve got both types on the bench at the same time.

This morning I read (On the 85-86, it is extremely easy to pull the top end because there is no power valve to deal with), The 85-86, I think, which is now on my bench does have a power valve, HELP ME PLEASE.

ope:

ope:

ope:

ope:

ope:

Hopefully when I return from breakfast, I’ll have an answer from you fellows?

Since the 2 stroke is long gone, so are all of the big bore kits. After I get all of this straightened out, We will start doing them again. LT250's

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winkdogg

Discussion Starter · #6 · Sep 20, 2014

John Tice said:
Hi Guy’s; I need your help unscrambling these 2 different LT250 cylinders.
Is this correct? 85-86 larger bore, larger reed; 87-92 smaller bore, smaller reed. The 2 on the bench both have power valves. Do they each have the same stroke??

Both years will take a 72mm bore so what might be the best choice for a performance engine? We also need to know, how large can we bore the cases for the larger diameter sleeve.

Over time I’ve read threads about these 2 years plus head stud problems. As I work on many LT250 cylinders I’ve never paid any attention to which is which. Now that I’ve got both types on the bench at the same time.

This morning I read (On the 85-86, it is extremely easy to pull the top end because there is no power valve to deal with), The 85-86, I think, which is now on my bench does have a power valve, HELP ME PLEASE.
ope:ope:ope:ope:ope:

Hopefully when I return from breakfast, I’ll have an answer from you fellows?

Since the 2 stroke is long gone, so are all of the big bore kits. After I get all of this straightened out, We will start doing them again. LT250's

85-86 have no power valve and no motor mount on the head. 87+ has a powervalve with the glass window . that much i know for a fact! WINKDOGG

mgty3whlr

· #7 · Sep 20, 2014 (Edited)

Sorry John for not responding sooner.
what you have on the bench is an '87 pictured on the right of your photo..the cylinder on left is an 88- cylinder.

The way to identify the cylinders...

85-86....no bolt on reed cage..just a single reed set on the bottom of the cylinder.
that's where on a previous post, I was talking about the "twisted style" piston.

'87...which is the one pictured on the right hand side is easily identifiable as it has 5 bolts for the reed cage. The Only year that they used that set-up on the LT250's

'88 and up use 6 bolts to hold the reed cage.

A lot of guys like the '87 cylinder because obviously it is the largest intake of the 250's

'85-86 cylinders use a bigger piston and shorter stroke where as the 87-92 use a smaller piston and longer stroke.
That's where I use the latter year rod with the earlier motors (85-86) to make the long rod set-up.

Hope that helps you John.

Joe

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mgty3whlr

· #8 · Sep 20, 2014

Also...If the cylinder or cylinders on the bench have a 72mm bore... They are "big bore" motors because I have a Polaris watercraft piston in my '88 motor and that is just beyond max bore at 69.70mm.

Joe

John Tice

· #9 · Sep 20, 2014 (Edited)

Thanks Joe; I've updated my picture & will hang it on the wall.
John

winkdogg

Discussion Starter · #10 · Sep 21, 2014

ok guys new symptom with everything fresh and clean im getting gas blowing back out of the carb (airbox is off right now ) now since i was told it just got a new piston and rings is it possible the piston was put in backwards? ive never seen or heard anything including air come out of the exhaust either it just constantly pushes air and fuel out of the carb . when i had the carb off it was pushing mist out of the intake too (alot) its a rather simple engine i know but ive never seen any 2 stroke push so much out the back end of a carb ??

John Tice

· #11 · Sep 21, 2014 (Edited)

Bad Reed Valves?
With the amounts of small problems, maybe you had better check your skirt clearance. Don’t always trust the person who bores your cylinder, the hone can cost as much as a kwik way boring bar.

717innovations

· #12 · Sep 22, 2014

Pull your reeds out hold it up to the light and see if they are not seated again a the cage.

winkdogg

Discussion Starter · #13 · Sep 22, 2014

John Tice said:
Bad Reed Valves?
With the amounts of small problems, maybe you had better check your skirt clearance. Don’t always trust the person who bores your cylinder, the hone can cost as much as a kwik way boring bar.

717innovations said:
Pull your reeds out hold it up to the light and see if they are not seated again a the cage.

well since i ordered top end gasket set i will have a new jug gasket .. so i ordered reeds too , thats the only reason i can think that its pushing air backwards through the carb. i was told its a stock bore and was lightly honed when the new piston and rings were installed . when i first got it the plug was brand new looking so my guess last owner just did the hone and piston/rings without bothering to check the reeds and never got it started again (hence why i scored it for $350) its a crap design hiding the reeds under the jug you cant even see them with the carb off you just get a direct look at the piston going up and down and blowing gas and air at you ! i lit a lighter to the intake with the carb off and it blew out flames with each kick till it blew out the flames . i know for sure the carb is supposed to suck in air and fuel not shoot it out! also i see traces of orange rtv sealant around the base gasket which i dont like at all so im hoping it seals up nice with a new gasket set . its almost like the motor is running backwards pushing out of the carb instead of sucking in?????????? any other ideas or comments are welcome! also the coolant level hasnt dropped at all since i flushed and changed the cooland so i dont think the jug is cracked or anything .

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John Tice

· #14 · Sep 22, 2014 (Edited)

Don’t give up Mate; 2 strokes are so simple & a joy to work on once you get past this.

Spark
Compression
Jetting
Air leaks

This kind of thing sure can be frustrating.
Stick with E2S, we’ll help you get past this & you will have a bunch of new friends along the way. All of us are learning from the problem.

I keep harping on the new folks in E2S but you also could use a copy of “Performance Tuning”.

John
:thumbsup:

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winkdogg

Discussion Starter · #15 · Sep 22, 2014

John Tice said:
Don’t give up Mate; 2 strokes are so simple & a joy to work on once you get past this.

Spark
Compression
Jetting
Air leaks

This kind of thing sure can be frustrating.
Stick with E2S, we’ll help you get past this & you will have a bunch of new friends along the way. All of us are learning from the problem.

I keep harping on the new folks in E2S but you also could use a copy of “Performance Tuning”.

John
:thumbsup:

im not going anywhere or giving up ive just never worked on an 85-86 and never seen a 2 stroke blow back from a carb so hard but we will get it together and it will rip , that much i know! i also have a 87 with a yz250 motor in it . i will upload all my pics to photobucket so i can share some of my toys with you guys for all the help and advice your giving me ! i got a Tusk top end gasket set today and the reeds should be here tomorrow or wed so i will get it figured out . i actually read some good things about the 85-86 motors on here and most of the other sites trash them i just like keeping the 2 strokes alive ! i never give up on them! the yz 250 swap had electrical issues but i figured it all out so im sure we can get to the bottom of this 85-86 motor and get it screaming!

thx again Winkdogg

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winkdogg

Discussion Starter · #16 · Sep 22, 2014

and ps i have a pdf of "2 Stroke Performance Tuning " some where on this hard drive and it is full of all types of great info. if i can i will post it !

winkdogg

Discussion Starter · #17 · Sep 24, 2014

ITS ALIVE!!!!!!!!! I decided to rip the top end off of it today so i went to pull the pipe and it was completely filled with gas/oil/carbon sludge the entire "U" was full there for not letting the exhaust exit and forcing the gas backwards out of the carb! it fired with 1 kick with the pipe off so i killed it quickly cleaned out the pipe and now it starts in 1-2 kicks! i may still re gasket the top end and put the 2 stage reeds in it but for now im going to start cleaning up the wiring and looking for new plastics! i also have alot of painting to do its got spray paint all over it !

ps looking for decent used plastics but i want to keep the wide seat!

John Tice

· #18 · Sep 24, 2014

Sounds good; Stick with E2S

winkdogg

Discussion Starter · #19 · Sep 24, 2014

im here to stay bro thanks!

winkdogg

Discussion Starter · #20 · Sep 27, 2014 (Edited)

HOGGING MY OWN THREAD TO SHOW OF MY LT'S!!!!!!

http://s31.photobucket.com/user/winkspics/library/lt250r stuff?sort=3&page=1

FIRST YOU WILL SEE THE 85 (THAT IS NOW RUNNING GREAT BUT STILL UGLY ) IM TRYING TO FIND PLASTICS BECAUSE THE STOCKERS ARE CRAP AS YOU CAN SEE . I WAS THINKING ABOUT STRIPPING THEM AND PLASTIC WELDING THEM BUT I THINK THEY ARE TOO BAD TO FIX. BUT I MIGHT TRY IT ANYWAY I CAN STEAL SOME PLASTIC FROM UNDER THE SEAT OR CUT THE BACK FENDERS INTO POINTS LIKE THE LTZ450???

92 COMPLETELY STOCK EXCEPT HEADLIGHT AND TIRES AND WHEELS(WHICH I STILL HAVE) NEVER EVEN BEEN REBUILT BOUGHT IT FOR $500 IN DELAWARE USA . IT JUST NEEDED A KICKER SPRING AND CLUTCH PLATES BUT STILL STARTS 1-2 KICKS EVEN AFTER SITTING FOR A FEW WEEKS !

87 FRANKEN QUAD WITH THE 1989 YZ250 MOTOR IN IT VERY MINOR MODS TO MAKE IT FIT THAT ALSO IS A GOOD RELIABLE BIKE SINCE I PUT THE NEW HOT STATOR IN IT! ITS A BEAST PROBABLY MY FASTEST 250R EVER! AND I HAD QUITE A FEW !

ALSO JUST BOUGHT A 88 (I THINK) LT500R FRAME AND SUSPENSION IT SHOULD BE BLASTED BY TUES OR WEDS THIS WEEK , I WILL UPDATE WITH PICS WHEN THINGS ARE COMING ALONG WITH THAT MIGHT GET IT COATED (POWDER) OR JUST PAINT IT A FEW COATS !!!

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