Wierd issues...

[mrhedges]

So I recently got my carbs mostly sorted with the help of a friend and the bike running. I went out for a ride tonight. There is a lonely stretch of road by my house with no stop lights. I planned to go up there turn around and find a parking lot to practice. I just got my license recently.



My current starting procedure is to open the choke. Start the bike and put my gear on while it warms up. I've noticed that the Choke slides down. Which is funny because when I got the bike the choke plunger was to sticky and I could barely pull it up. I PB blasted it and now it's to loose.


I get the bike up to running temp I get on and go. I'm most of the way through the stretch coming up to a red. I engine brake down to 3^rd. The bike starts running weird, very uneven, then I have no throttle response. I pull the bike over and it dies. I try to restart. Nothing. I open the choke and try again. It runs for a sec the dies. I get off the bike take off my helmet and gear. I text my girlfriend and my buddy who helped me with the carbs. I decide to walk to the gas station across the street to get a snack and consider my options. While I don't feel unsafe at my present location I would not want to leave anything unattended there for very long.


I eat my chips and decide to try to start the bike again. With the choke open It's running and it's getting throttle. The throttle is uneven and even slow. The choke falls back down and it's idling at just under 1k. I figure it's good enough to try to get home. On the way home it seems to be running normally. I pull into my driveway park the bike and my buddy gives me a ring.


He seems to think it's a fuel issue and tells me to check the fuel lines. They seem ok to me. I should say here that he knows his stuff and based on what I know about these bikes he did everything right. We replaced the O-rings and he set the floats. He does good work. While we were trouble shooting the bike we checked the compression all 4 were in spec though one was 5 psi higher. The bike has just over 10000 miles. I have no ideal if it has ever had a valve check. I am thinking this might be an issue. When it's warming up and it idles pretty low like under or around 1k and I can hear a slight rattle. It goes away once the bike idles above about 1.2k. He seems to think that that's a cam chain issue.



What do you guys think?

[gsrick]

How far did you get before it started loosing power? I'm guessing that maybe you petcock may be malfunctioning or possibly clogged filters in the tank. My thought is if it was just down the road, maybe your fuel bowls dried up from inadequate fuel flow to the carbs. Try undoing the hose at the petcock and put on some spare hose then put the petcock on prime and see how well the fuel flows. This won't tell how the diaphram is working, but it will let you know if the filters in the tank are clogged. You can also try the prime while it's running if it starts loosing power while riding, this will basically be bypassing the diaphram. If it picks up power, then the diaphram may be stuck or the vacuum line may be clogged.

BTW, on some models if you twist the choke knob clockwise it will stay up.

[mrhedges]

Thanks. I rode the bike maybe 3 miles. I cleaned out the tank filter when I first got the bike. Gonna try that thing with the choke knob. This is good advise and basically what he told me.

[2BRacing]

If you remove the handlebar pad around the choke knob (4 screws underneath), you will see a knurled plastic ring at the base of the choke knob. There may be a rubber cover over it, so just flip the rubber cover up, and you will see the knurled ring.

Turn it clockwise to stiffen up the choke cable to prevent it from sliding down again. This is like a "friction" mechanism, and your PB Blaster spray has made the mechanism slippery inside.

[steve murdoch]

Another thing that can stop fuel flow is a clogged vent in a tank cap.

[eil]

What the other guys said about the other stuff. It does sound a lot like a clogged petcock or something of the sort.

Also, check the valve clearances as soon as you can. With only 10k miles they're almost certainly just fine if the bike starts up without much complaint.

When it's warming up and it idles pretty low like under or around 1k and I can hear a slight rattle. It goes away once the bike idles above about 1.2k. He seems to think that that's a cam chain issue.

This is a very normal noise but if you want to be sure, the cam chain tensioner is easy to rebuild and check out. Just need a couple of seals and a gasket. There are forum threads about the process.

[mrhedges]

This is a very normal noise but if you want to be sure, the cam chain tensioner is easy to rebuild and check out. Just need a couple of seals and a gasket. There are forum threads about the process.[/COLOR]

That is good to know. Thanks. I will file it under eventually fix that. I think that gasket is seeping oil so I'd be good to fix eventually. The Valve gasket is definitely leaking so that's the next thing.

[Crankthat]

If it dies again, try running with the gas cap off.
Though it has not happened to me 2-3 miles is what I read on another thread years ago.

[bonanzadave]

I have no ideal if it has ever had a valve check. What do you guys think?

Do that sooner than later. Setting valve clearance is mucho important.

[mrhedges]

Do that sooner than later. Setting valve clearance is mucho important.

Yea this and putting new tires on it are very high on my priorities before putting any serious miles on her.