help, dies off/back fires in upper rpm's/no power

[snowfoxsx]

okay, my shee (FIRST ONE) is bored .060, paul turner porting in the jugs and case ported, tors is disabled, 13/42 gearing, stock pipes(but not for long), boysen reeds, no air box lid. temps are around 80 degrees and about 750-900 elevation. IT IS AN 89/90 i was told

 

the trouble is that 2 rides ago it was running fine at first, running smooth and had tons of power through the band, did some trail riding and came out onto a road and opened it up and it was spitting and backfiring like crazy, could not even pull 6th gear and barely 5th!! it idles fine and revs fine with no load but dies out under load, it still runs but has no power? the plugs were new before that ride but i never changed them yet, i will tommorow and test it. any other ideas on what is causing it to run like crap. i guess i will pull the carbs and clean then, check the sync of them and see what size the jets are in it.

 

would anyone know as a rough guess on what kind of jetting, needle settings i would need for it so i have a base to start setting it up.

 

my riding here consists of tight bush trails, fire roads and some pits to play in, does it look to be geared right or can you give me some suggestions to set up that end of it, what kind of speed can i expect out of it like this versus another setup?

 

sorry for the long post, by the way the crank was rebuilt on it, would that do anything if it went out of spec? and i am looking for a cheap set of pipes and some info on how to read the vin# on my bike

[pimpeinkc]

i have the tr6 toomeys on my bike, it came with the t5, i am going back, the t5 pulls hard when the powerband hits and don't let up on the top. the tr6 seems to be lacking.

 

as for your problem sounds like you need to clean your carbs, and i would check the line. depending on where you got it and if it had sat around, i think cleaning out the tank and petcock couldn't hurt.

 

i am always doing little things to my bike, here and there just so when i do have a problem, i know what i can count out right away. good luck

[sredish]

13/42 sounds way to low for me. I'd run a 14/41 minimum and probably a 15/41 like I do on my bike. WIth that portwork, you'll want the extra gearing, I promise you.

 

Also, your problem could be jetting, electrical, or lots of things. You need to get into the carbs and see what size mains you have in there ,because if it was jetting thta'd be where the problem lies.

 

Will it do it if your idling and the punch the throttle revving it hard?

[snowfoxsx]

if it is idleling and i punch it hard it will rev with no trouble, like it should, so i do not understand? there is no bog, backfire or anything weird. that is under no load.

 

but under load and going through the gears it will pull hard through the first couple of gears and then fall flat and start dieing off/backfiring and stuff?

 

thanks for the help guys, i am new at owning a shee

Edited June 25, 2005 by snowfoxsx

[snowfoxsx]

cleaned the carbs and it runs great, it has 240 mains and 25 pilets in it, does that sound right? also i noticed that the needles are 2 different sizes/taper,one is thicker, is that right?

 

thanks

[sredish]

cleaned the carbs and  it runs great, it has 240 mains and 25 pilets in it, does that sound right? also i noticed that the needles are 2 different sizes/taper,one is thicker,  is that right?

 

thanks

385723[/snapback]

 

that sounds awfully lean on the main for a ported motor. what kind of pipes are you running? typically, you wouldn't run a different tapered needle in one carb.