Bonneville America Forums Forums Technical Forums General Tech Help! stuttering, then dying...

Yesterday I rode my bike to band practise, it's approx. 60 mile ride one way. In ran really good on the highway speeds 60-70 mph, but at lower speeds, around 35-45 it started to stutter, like I had to switch to reserve. When I pulled the clutch it idled fine, but when I put on load, it would run good for another minute then start to sputter igain.

It still ran good at high speeds.

On the way home it started to run rough at highway speeds, that suddenly it would die on me on all levels. If I went 35, or 75 didn't matter. The bike would stall, then give a loud backfire. Not a right side or left side power loss, complete shut down but all lights still work, dash and heads. I pulled the clutch and pushed the starter, it started fine, and i reved just fine. Ran for 2-3 minutes before acting up again. It did that for 5 or 6 times, and then suddenly it ran good for a couple of miles again.

What's wring with my bike? The plugs are new (have probably just 150 miles on them), gas is good and pulling the choke didn't help the problem.

Was it raining?

nope. Good weather, warm but not too hot either. Approx. 24 degrees C. (75 F)

I would drain the float bowls and check to see what's coming out. You might have some water in the gas.

m'kay, will check...

Have a close look at the vacuum plugs on both ends of the manifold, too. They can dry rot and cause similar symptoms.

the plug on the right hand side of the bike, on the intake manifold looks a little dry and have small cracks. Perhaps that's the culprit? But I don't have any replacement plug.

Could the gas tank vent tube be kinked or otherwise blocked? The next time it does it, try loosening the gas cap and see if it straightens out.

What I don't understand is that it's not constant. At first it was at low speed, that it got progressively worse. But when I start it now, it runs fine again. For a while, then it comes and goes again. But will try to check the tank vent also.

have a look at your hidden fuel filter too.

First of, there is nothing like getting up early in the morning, brew som coffee and then head out to the garage and hoping to fix the motorcycle before heading off to work, hopefully on two wheels!

Drain the bowls and check gas? Ok.
Checked the tank vent? Ok.
Remove bowls and check for obstruction? Ok.
Check plugwires? Ok.
Pretend to be the mechanic eqvivalent of Indiana Jones, in the quest for the hidden fuelfilter? Ok. (Found it! yay! Clean as new fallen snow though)

Check airfilters?
Ops, seems like the freak-pods were a little loose, I could just barely touch them and they fell off from the carb. Secured them tightly and then went out to test the bike, it seemed okay so I took the bike to work (55 miles one way) and didn't have any problems what so ever at any speeds so hopefully it was just the loose pods that was the problem.

But I will find new vacuum caps though.

Thanks for all the pointers guys! If she starts being moody again, I'll let you know.

EDIT: I didn't plug in the TPS either when reassembling the carbs after checking the float bowls, and I actuallt think I got a little more gurgle when pulling the clutch... It is kinda cool.

Thanks for the update especially the TPS point. Something to consider in the future. Now that I think about it, my bike was doing the same thing a couple of summers ago. Ended up doing the same thing and disconnecting my TPS. Here is the Post I made . It seems we had very similar symptoms. My problems appear to be gone....knock on wood

Hm, maybe I should try to connect the TPS again, to see if anything happens?