so the story goes, i fire the bike up in the morning then when i start headin down the street and it starts buckin and it feels like its running out of fuel, then dies and wont refire, but sometimes if i rev the s**t outta it, it may keep running and run fine for the rest of the day. so i got it home and pulled the vacuum diaphram out of the petcock, threw it back in and it fired right up. so even if the diaphram looks good could it still be baqd, or could it be another problem?

 

Could be sticking floats in the carb, tap on all of the float bowls with the handle of a screwdriver to try and free any stuck floats.

If you know how, clean the carbs out and see if the float needles have any wear on them.

 

thats a good idea, i'll give that a try next time this happens. I dont know if it makes a difference but this seems to only be happening in the morning. could the engine not be creating enough vacuum when cold?

 

Did this problem just appear out of nowhere, or did you recently buy the bike, have it worked on, or decided to tinker with it yourself? Did the bike sit unused for any length of time?

Knowing whether this started to happen out of the blue after running perfect a week ago, makes figuring out the problem easier.

 

i bought the bike at the start of the riding season, rode it just fine for the first few weeks then it started happening. the guy i bought it off said he hadnt ridden it for 1 or 2 seasons. i havent checked the filter in the petcock, and i dont really want to take the bike apart to do the carbs ect. until the end of riding season cause i will have to do it then anyway cause it could use a new cam chain. the reason i dont want to do it now is because i dont want to miss out on riding time, but i suppose i cant ride it anyway if it dont run! im just hoping its something simple, but i doubt it.
I was thinkin of running a bottle of that "seafoam" carb/intake cleaner through it, just wonderin if anyone else has done this or if its a good idea?

Thanks

 

I've never used the seafoam stuff, I always clean mine the old school take it apart and get dirty way. I would do some google searches on the product to see what the word around town is.

As for your bike. Try running it at different throttle positions for a few minutes. So, start the bike, (how well does it start?) Let it sit idle for a while, how does it do there? Go out and find a stretch of road which you can cruise in 2nd gear 1/4th throttle, and keep moving along to full throttle. If this only happens during idle or very low speeds, your fuel screws may just need adjusted. If it has problems in other throttle positions it may be something else. But if the bike runs well when moving fast then you can probably rule out anything from the fuel tank to the floats, its after that you gotta start looking.

 

waste of time.... clean the carbs and you will be golden.

 

I agree, about the seafoam stuff anyway... As for tuning, if you have the carbs off, you should already be cleaning them, but its nice to make adjustments while you are already at it.

 

My 91 f2 used to do the same thing only in the am. stall out. if i waited til later in the day it was fine. All i did was tune my carbs. I had a difference in 12inches of vacuum from highest to lowest carb (1.2 is the maximum in book allowed) after i did this i could start my bike no choke been good for 2 yrs got 36,000 on it now.. it just sits now tho.

 

+1 same thing happened to me. I bought the bike and it rode like a champ, later it died and wouldn't start up. cleaned the carbs; she's golden now. :-)