Everything2Stroke Forum banner

1 - 8 of 8 Posts

·
Super Moderator
Joined
·
6,688 Posts
Discussion Starter #1
Originally Posted by jkylnhyde
Credit given to RB Designs LLC

These guys are pretty popular in the MX circles for cutting heads and Carb Boring .. Along with a bunch of other machine services

Sorry, the pics didnt come up



Read and understand the following before measuring squish

These test solders are my only look into your engine so that I know what needs to be done without actually having the engine in front of me. So, it is very important that you pay close attention to the process and do the solder tests with great care. Your head will be modified using these solders that you have provided me.

As you can see in the example pic's below, (these pic's are examples only and may not show your particular engine, but the idea and process is the same) the solder is to lay flat across the top of the piston, over the center line of the piston pin with a small "camel hump" that also lays flat on top of the piston.

The pic's below are examples only, your engine may look a little different, but the idea is the same for most all two stroke engines.







One last note before you go on to the actual Measuring Squish, make sure that the ends of the solder touch the cylinder wall on both sides and that both ends are cut blunt and clean (blunt and clean on the ends is very important).


These are examples of how your test solders should look.

The reason for the small hump is to allow you to either pull the ends farther apart or push the ends closer together. This will allow you to get both ends of the solder to touch and rub on the cylinder wall.

The hump shape of the solder is to lay flat on top of the piston, also this will keep the solder from moving around and help keep it in place. It is also very important that the hump shape of the solder does not come in contact with the squish band area.







One last note before you go on to the actual Measuring Squish, make sure that the ends of the solder touch the cylinder wall on both sides and that both ends are cut blunt and clean (blunt and clean on the ends is very important).

Again I can not stress enough the importance of the solder tests. Send at least 3 tests solders with the head to be modified, they are easy to do.




The test solder below were done improperly.

These are some examples of poorly done solder tests. You must keep the hump shape of the solder small enough, so it will not come in contact with the squish band. If this hump shape comes in contact with the the squish band, it will deflect the piston and may give an incorrect reading on the ends of the solder.
Picture to the left were done incorrectly







It is very important that the ends of the test solder are cut clean and blunt. This is a very critical area to be measured, it is this measurement that will be used to do your head modification.
Picture left were done incorrectly






Now it's time to Measure Squish Band Clearance

The best and easiest way to do this is by using a piece of rosin-core or acid core-solder (Do not use a solid, core-less type of solder). You can buy the rosin or acid core solder from your local hardware store, auto parts stores or places like radio shack. The solder needs to be thick enough to smash slightly but not so thick as to bind the engine (after you do it a few times you will get the hang of it).

Places to get your test solder

.050" Rosin Core Solder = Radio Shack PN # 64-006 E
.062" Rosin Core Solder = Radio Shack PN # 64-002 E
.093" Rosin Core Solder = NAPA Auto Parts PN # 777-1862
.125" Acid Core Solder = NAPA Auto Parts PN # 777-1857

The first thing you need to do is remove the flywheel cover, this will allow you to turn the engine by hand. Next you will need to remove the head and save the old head gasket if it uses one (some engines do not use a head gasket, they use o-rings and the o-rings are not necessary for this test). You will then need to bend the solder into a hump shape shown in the pic’s above.

Now turn the flywheel by hand or use a wrench on the flywheel nut and lower the piston about 3/8" to 1/2" below TDC. Note, you do not want to move the piston down any lower than this during the testing procedure.

The solder needs to lay right across the center line of the piston pin. Make sure the ends of the solder touch the bore of the cylinder on both sides. You can use a small dab of grease on the hump shape that should be laying flat on the top of the piston also, this help hold it into place.

Next install the head and use your old head gasket if it used one (o-ring seal type of heads do not use a head gasket and the o-rings are not necessary for this test) and snug it down with the head nuts. Now carefully turn the crank shaft rotating the piston over TDC by hand or wrench on the flywheel nut. You will feel a slight bind and this is normal. Rock it back and forth a couple of times over TDC and then remove the head. DO NOT USE THE KICK STARTER TO ROTATE THE ENGINE, TURN THE FLYWHEEL BY HAND. It is not necessary to move the piston any more than about 3/8” to 1/2” below TDC.

You will see where the solder was smashed and this is your current squish band clearance. You will need to send at least 3 of these test solders to me with the head to be modified so I can re-cut your head for an optimum squish band clearance and volume.


thanks for the good info! e2s management
 

·
Registered
Joined
·
497 Posts
All Credit given to RB Designs LLC

Pictures are in order

squish
squish-test
good-solder-test-1
good-solder-test-2
bad-test-solder1
bad-test-solder2
 

·
Super Moderator
Joined
·
6,688 Posts
Discussion Starter #4
Thanks jekyl for the info !!!i made sure the credit you gave was at the top of the post from the other thread!! + rep for you when we get it working!!
 

·
Super Moderator
Joined
·
6,688 Posts
Discussion Starter #5
jekyl can you post these in the thread as IMG's or forward me the links and I can do it! his way they are blown up for the visually impaired.. right scott?
 

·
PLAYTIME'S OVER BITCHES!!
Joined
·
13,056 Posts
jekyl can you post these in the thread as IMG's or forward me the links and I can do it! his way they are blown up for the visually impaired.. right scott?
yup!!!!:thumbsup:
 

·
Registered
Joined
·
2,661 Posts
great info very helpful
 
1 - 8 of 8 Posts
Top