Flooded?? Idk?

[ZeroShadez]

So the bike was running great other then the clutch kept comming loose it was the clutch hub nut i torqued it to spec and got that good to go next day. I try to start the bike. Nothing. I though it was flooded considering i need to clamp off the fuel line on the right side after every ride. And then it would start 1 kick no problem. So i clamped it off left it over night. Still wont start up. If i hold throttle wide open it will fire occasionally long enough for a single rev then it dies out and wont do it again for another 20 kicks.

 

[Bushyeyed1]

So I assume you are clamping it off to stop fuel flow. We will need more details to help diagnose the problem. Start with the year make and model of your bike.

 

[ZeroShadez]

So I assume you are clamping it off to stop fuel flow. We will need more details to help diagnose the problem. Start with the year make and model of your bike.

1978 XS650 special. So i got it going again but now its leaking fuel out of the airfilter again a week ago i had cleaned the carbs. Cleaned float needle and under the seat and that stopped the problem. Until now.

 

[joebgd]

Set floats to shut gas sooner, a little more than the suggested plastic 7/8" and brass ab 1 1/16". Id try adding 1/4'. You might need new float valve needles but this might get you riding till you get them. I got mine from Mike's years ago and they are working great the tip is nice and soft so it does a good seal. Does your tank have a petcock w an off position?

 

[ZeroShadez]

Set floats to shut gas sooner, a little more than the suggested plastic 7/8" and brass ab 1 1/16". Id try adding 1/4'. You might need new float valve needles but this might get you riding till you get them. I got mine from Mike's years ago and they are working great the tip is nice and soft so it does a good seal. Does your tank have a petcock w an off position?

No but i added a inline fuel shutoff valve. These needles are metal tipped not rubber like i see on alot of them. The little pin moves up and down proper so maybe its just the float height?

 

[joebgd]

I think I'd def get new float needles for sure then. Do they come to a point? The rubber tip can fall off.
If you need to ride then try adjusting the height. Careful w those brass floats I had one mangled and broke the tab off trying to stop a leak working on it on the bike.

 

[ZeroShadez]

I think I'd def get new float needles for sure then. Do they come to a point? The rubber tip can fall off.
If you need to ride then try adjusting the height. Careful w those brass floats I had one mangled and broke the tab off trying to stop a leak working on it on the bike.

They do come to a point thats just the way these are no rubber on them. I think i have crud keeping them open but i just cleaned it all so idk how

 

[joebgd]

Did you ever have the floats off? Could be one has gas in it?

 

[5twins]

Yes, '78 float needles would be all metal, not rubber tipped. The Viton rubber tipped needles didn't come along until 1980 and the BS34 carbs. You have BS38 carbs. You might need new needle and seat assemblies. The metal ones do wear out eventually. I recommend getting genuine Yamaha replacements. The aftermarket ones are hit and miss. Some work but many leak right out of the box. Originals aren't that expensive and it should be a one time investment.

https://www.partzilla.com/product/y...?ref=c490092540a27afb176c627262ae2473d2405817

 

[ZeroShadez]

Yes, '78 float needles would be all metal, not rubber tipped. The Viton rubber tipped needles didn't come along until 1980 and the BS34 carbs. You have BS38 carbs. You might need new needle and seat assemblies. The metal ones do wear out eventually. I recommend getting genuine Yamaha replacements. The aftermarket ones are hit and miss. Some work but many leak right out of the box. Originals aren't that expensive and it should be a one time investment.

https://www.partzilla.com/product/y...?ref=c490092540a27afb176c627262ae2473d2405817

I got it all taken care of works great now no flooding needed inline filters was ass bike rides great! All i need to do now is figure out where the airleak is because it likes to idle at 3k sometimes. Not all the time but sometimes and it takes a min for it to come back down and ot idles great at 1500.

 

[5twins]

1500 is still a bit high. Idle speed should be around 1100 to 1200. If you have it set too high, the ignition can begin to advance. When it does this, the RPMs start to increase, which causes more advance and more RPM increase. The bike can sit there and rev up to 2 or 3K without you even touching the throttle. So, your high idle speed may be causing your random 3K revving.

 

[ZeroShadez]

1500 is still a bit high. Idle speed should be around 1100 to 1200. If you have it set too high, the ignition can begin to advance. When it does this, the RPMs start to increase, which causes more advance and more RPM increase. The bike can sit there and rev up to 2 or 3K without you even touching the throttle. So, your high idle speed may be causing your random 3K revving.

What do you mean advance

 

[5twins]

The ignition or timing advance.