Wierd running problems

[Lbrown311]

So I drove my bike 60 miles yesterday. It ran fine. when I tried to drive it the last couple times it has been dying on me at low RPM's. It will take a very slow throttle and eventually will go, but as soon as I stop at an intersection it wants to die. This happened twice today and the other two times I took it out it ran fine. When I filled up with gas I thought of another thread I read that said try running it with the gas cap opened and see if that helps. Well it shut off on me as I pulled into the gas station and I started it with a full tank of gas with the gas cap open. It ran fine all the way home. Definately seems like a fuel issue. Carbs are cleaned and synced. I wanna tune with Color Tune and then sync again, but like I said...for now it ran 60 miles with no problems. I stopped at a Yamaha shop and he sprayed some silicon stuff on random parts (frame, 2 spark plug wires, wheel, carb boots, shaft drive boot) to show me what it looks like to jazz up the bike appearance wise. Doubt that did anything but it started acting up after I parked it and rode it later that day. It has a bit of a rough idle, will warm up, then run for a few blocks normal, then it wants to die at idle conditions. ????

PS the silicon stuff my buddy used at the Yamaha shop was pretty incredible for jazzing up black parts. I will find it out and post it on my way home (If I can get the bike back there)

[BA80]

Check your sync on the carbs that's what it sounds like to me.

[TopCatGr58]

Gotta Ask....

Did you install the inline fuel filters?? Those tiny rust/dirt particles can clog up the small orifices of the pilot circuit pretty easily/quickly!

Also, did you ever to the Charging system analysis at least.....battery could be running low and at idle, not cranking out enough juice to keep the ignition system sparking properly??

Lots of things could be contributing to this, fuel, electrical, etc.!

T.C.

[Shacknasty]

If the vent in yer cap is clogged it will prevent the flow of fuel. When ya crack open the cap and it runs normally, that is a sign of a blocked vent. The cap can be disassembled and cleaned.

[DGXSER]

If it runs better with the gas cap open, then as Shack stated its the gas cap vent. You can pull that apart and clean it out, you may find that cures your problem.

[Lbrown311]

No filters yet, tank isn't terribly rusty, just spotty. I will be cleaning it and installing inline filters, as well as...the way it sounds, checking the jets and bowls for cleanliness. gonna check the electrical in a bit. Hopefully have good results there.

[oldyam80sg]

Tank isn't terribly rusty-one of your issues if no filters.

[Lbrown311]

Working on the rusty tank. Don't just wanna supplement in-line fuel filters for a rusty tank. Would like both, so I am working on getting a clean and newly painted tank. After bringing the bike home (it ran pretty good) I resync'd the carbies today, and they were a bit outa wack. I could tell the difference in the idle when I got it right. The SyncPro says it need to be calibrated each time its used, and on the non-adjustable carb. On our bikes that is carb no.3. I did it on 2 for some reason last time. Not sure if that makes a huge difference, but it seemed to run a lot better when calibrated on no.3. Just need to get the Color Tune, Clean Tank, and in-line filters. In the mean time I will probably rebuild the front forks as the oil seals are leaking. Don't wanna ride to much with them leaking. Hopefully this week. Was told to get the Yamaha OEM seals as they last the longest. It's coming along really well right now. Will eventually do compression check and see how the engine is doing. Only 27k on it, so hopefully they are all ok. Sure have learned a lot in this process, and its been a lot of fun. Feels really good when you get something fixed and it works "properly" Here is a little pic of her as of now.

[bikerphil]

A temporary fix for leaky fork seals is pop up the black rubber dust covers, rip off a piece of paper towel and wrap it around the upper tube above the seal. Slide the dust boot back down and snap it back into place. It'll get you down the road for a while without oil getting down on your rotors/brake pads.