engine advice/help?

[fruehjames]

After taking apart the top and bottom end of the motor to install new gaskets and fix a stripped head post I got the blaster back together and slowly broke her in. It has been running fine until today when it began sputtering in fifth and sixth gear. It will run fine for most of the time but every now and then when in higher gears when I give it gas it just doesnt respond. In one instance the engine just cut out completly when I was cruising along in 6th gear. Anyone have any idea what might be causing this maybe the fuel - air ratiO... im not sure. Any help would b greatly appreciated.

 

[brandoz28]

what mods have been done to the bike? what are you running for jetting

 

[fruehjames]

only mod on the bike is an fmf fatty and powercore silencer and clamp on air filter.... and to be honest i dont know how to check the jetting ive only owned the bike for about a month and a half.

 

[fruehjames]

could the screw on the carb that adjusts fuel air ratio cause this?

 

[brandoz28]

not if its cutting out at high rpm's, it sounds like its probably running lean. pull the carb and look at the hex shaped jet in the middle and find a number on it, with those mods it should be 260-290

 

[fruehjames]

alrite im gonna go pull the carb in my opinion i thought it was running rich since the oil injector mixes at 20:1 ratio im not sure tho thats why i figured id consult the forum for advice.

 

[Blaster200boy]

yes, but no, the engine needs a/f mixture, that being said, you need to put a 260-290 (stated above) main jet...then the little a/f screw on the side of the carb (flywheel side) should be turned all the way in, then backed out 1.5 turns. take the oil injector off and mix it with Premix type oil, Bel-ray, klotz, amsoil works perfect. one of these days that thing will f*ck up and destroy your engine again...infact, that might have caused it to blow the previous time...for about $35 you can get a T.M. Designworks Oil Injection Block off Kit. extremely easy to install...

 

[fruehjames]

yeah im plannin on doin the blockoff very soon.... do you have to take apart the carb completely to check the jetting or just take it off the engine?

 

[brandoz28]

have to take it off the engine and take the float bowl off

 

[Blaster200boy]

Yup, you have to take the carb off, take the 4 screws off the bowl, then look at the middle hex jet....You have to look really close on the top of the jet to look for a number...