when i first start the bike it runs ruff and then you can hear it picking up cilnders when i gets warm it will idle kinda good there is still a miss but its not a constent miss when i drive it and at a cruz through town it sounds like a missfire but when i get on it lets say from 4k on up it runs sweet is this a carb sync thing and it smells like raw gas alot but i cant find any leaks this motor was just rebuilt the 4th cilnder the one all the way to the right gets warm but when i spray water on the header cilnders 123 are hot 4th one is warm but not hott like the others so i pulled the plug and its not wet and it has a nice carmal color its got good spark to the cilnder.....i went out to day and it would not start for like 10min of cranking mind u it was 29deg out this morning carbs are clean i just sont think it got synced

 

damn. you described what my bike is doing also (cept im on original motor of 13k miles). i havent tried to spray water on my exhaust pipes, i'll try that next start up. mine does this in any weather, even 80-90 degree days. im interested as to what responses come up.

 

yup mine does it all the time well any weather just today like high 20's out it took like 10min of cranking an when it started it ran like poop it seems like it clears out at high rpm so it would not be a problem if i could just drive it around at wot but the popo might not like it haha yeah it bothers me

 

as with any post on here ending in a question mark, people are going to ask you "are your carbs clean" or "when was the last time you cleaned them"???? mine are so clean nasa would give a stamp of approval.

 

yup mine too thats why i was thinking to sync the carbs if this can cauz it or if there was another knowen prob with the f3 tht could cauz this im going to get a book mabey i have a bad vac line? i dunno i have all winter i guess to work on it i fliped it the other day doing a stoppie the funny thing is is it ran better

 

Has anyone figured anything out about what this might be? Mine is doing the same thing..

 

nope not yet lol sounds like a commin prob with theese bikes

 

Carb bikes in general don't like low rpms. I have my F3 race bike tuned for mid to redline power, anything below 5K it doesn't like. Sould be interesting next year after the complete rebuild. Just put the lower engine block back together. Still working on the top end.

Max over bored cylinders per rule book. Race balanced and lightened crank. Thats just to start can't tell you everything.

Before anyone says anything. The suspension is anything but stock.

May do a write ups for some of the things I'm doing.

 

it just puzzles me why the #4 is so cool it should be hot like the rest if i go run the bike at high rpms #4 gets hotr like the rest im gunna clean the carbs yet again and have them synced ill post if it works

 

i can relate mine to being like a diesel... it starts running better and better the more warmed up it gets. how strong are ignitions on these bikes??? i have brand new spark plugs, and i checked the wires for ohms flow and they're fine also. will coil packs lose strength over time? just throwin some thoughts/ideas out there.