I recently installed a 38mm airstryker carb on my 87 310R. Took it out for a test run and it siezed up. I had ESR bore the cylinder and installed a new piston and rings. I also installed a new crank seal behind the flywheel to be safe. The motor wasn't sucking in tranny fluid so I figured that seal was ok. Took it out for break in and it seized again. The bike was running fine before I put this new carb in. I cannot think of what it might be. Could there be something wrong with the carb? I jetted up to 185 main and 50 pilot. The bike has the 310 w/ trx9 port, cool head, trx6 pipe, c/f boyeson reeds, cr reed cage, and ESR airbox eliminator. HELP!!

 

Do you have any pictures of the piston? The jetting specs are very close to what I run. What type of fuel is being used and what fuel is the motor set up for? I thinking you may have a fuel issue here.

 

I changed the needle clip from the 3rd position to the 5th position and changed the main to 190 and the stutter was gone. It ran smooth from 1st thru 4th at mid throttle with no problems. The plug was tan in color. I'm not going to push it until I have it checked for air leaks. Is it ok to have the needle in the 5th position or should I change it? The pilot is a 50, should I go up? I'm going to put in a 195 main and see how it runs. The needle is a DGH. Any suggestions?

 

I run a pump gas dome and run 91 octane. I use 927 oil at 32-1 mix.

 

Wow you must be in a really high altitude to have to be that rich! Anyway, 20% of the time when sombody puts in a crank seal it fails within an hour, so take off the flywheel cover and if you see any oil at all the crank seal is bad. Check to make sure the air boot has no cracks in it. Keep jetting up untill the plug looks tan or light brown.

 

You have got to have a air leak.......
i have about the same setup on one of my R's and i run
a 42 pilot and a 185 main and i'm perfect...

 

Where does the piston seize at? I have pressure testers on my website if interested.

 

sounds like a air leak. What is your elevation?