spits/sputters/hesitates

A leak down test is performed by testing for pressure leaks in the bottom end, below the piston. What you have done is a compression test.

There is a major possibility that your crank seals are leaking allowing air into the crankcase, if this is the case you may be running very lean, that would account for overheating.

The bottom end air leaks can also be caused by poorly fitting gaskets.

Replacing the crank seals is no so much of a hard job and can be done without breaking the cases apart.

Either make a leak down tester of get one ready made from a guy on the forum, and do a leak down test..

I am pretty confident that the crank seals are the problem.



wow i was doing entirely the worng test. i thought i was doing leakdown test and was doing compression test. i have been noobed.. thanks for the correction. now to do the actual leak down test.


thanks again guys
 
aha! an airleak i am sure of. jip comp test and leak test are different. let us in on your results, otherwise, you seem to know what you are doing, keep it up, you'l get the prob eventually!
 
i have found a a cylinder leak down tester but it seems like its for a car and wouldnt work on the bike. i have read that anything over 8psi could blow the seals anyways. this tester is to be hooked up to an air compressor and that is how the pressure is built up and seems that the air goes in through the spark plug.

Cylinder Leak-Down Tester

does anyone know if it will work or should i jsut go to home depot and build one?
 
you must never use a compressor to pressurise your bike motor! use a hand/bicycle pump.

as for using the spark plug hole, i guess that could work but then you need to find a way to block the carb boot off, your reeds alone wont hold i dont think.

If i were you, id build my own (which i did) took some time to get the actual tester leak proof, but use lots of PTFE tape when assembling all the threaded pieces.
 
Im not sure if you got this sorted out yet, but my brother and myself had the same issue after putting new Exhausts on and rejetted.
We had the issue on pull away, how ever we sorted it out by basically cutting out big holes in the air box lid and covering the lid with "Second skin" material, Immediately the sputtering and hesitation went away in low revs, did a spark plug reading and all was good as before the holes were made our plugs were BLACK!!!! they now a light tan/brown colour, but we went and got a 290 main jet just to be on the safe side as we both had 260's in for the new pipes!

This should sort out the issue!
 
$30 shipped from slickerthanyou save yourself some scourcing and sealing.

Nothing like doing it the right way, forget the spark plug hole method, you need to directly pressurize the crankcase!
 
$30 shipped from slickerthanyou save yourself some scourcing and sealing.

Nothing like doing it the right way, forget the spark plug hole method, you need to directly pressurize the crankcase!

how do i contact "slickerthanyou" to get one?.......i figured it out

mine is a 1995. is the intake hole and the exhaust hole the same size for all blasters?(not saying the 2 holes are the same size but, the intake hole is the same size for all blasters and same for eht exhuast hole) i was going to try and get something today but this might jsut save me alot of time and hassle. thanks blaaaster
 
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$30 shipped from slickerthanyou save yourself some scourcing and sealing.

Nothing like doing it the right way, forget the spark plug hole method, you need to directly pressurize the crankcase!

you can still pressurize the crankcase from the plug hole granted your piston is at BDC
 
"you can still pressurize the crankcase from the plug hole granted your piston is at BDC"

Agreed, but another variable for a noob to grasp..... Too much information! :)

Also you can only test for leaks at the crank seals and crankcase.
Good reeds will stop the pressure from getting to the reed case gaskets and rubber boot.
 
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