no guts!

[cloerts]

OK new problem, Everything is great until I get to cruising speed on the freeway. It get's there quick, but then it loses all power after a couple minutes. It then surges every five or six seconds like it's getting power back. If I slow down below 50 everything goes back to normal. I don't get it. bad carb parts? Bad float setting? Bad vacuum? HELP PLEASE!

[randy]

cloerts;

Two things:

1. Pickup coil wires intermittent.

2. fuel cap vent is plugged

[jeffe]

Agree with Randy and add:
Crimped fuel line or clogged screens in the tank or petcocks

[81xsproject]

Another thought, I had exactly the same issue after I shimmed my needles. Right at 50-55mph it would surge while cruzing. If I accelerated it would go away and I didn't have it above or below that range. Sounds like a fuel mixture problem to me. I think if it was the tank cap the bike would eventually stall out from what I have heard from all the other tank venting accounts.

[renegade_xs11g]

just a guess, but i had them same sort of prob, unplugged the line to the vacuum advance ( going into the ignition cover left of engine) capped the nipple, got a lot better.

[81xsproject]

Renagade, that is not the REAL solution to your problem, even if it did solve your symptoms.

[randy]

But it may have isolated the real problem - pickup wires?

[81xsproject]

good call Randy

[HobbyMan]

dang it. You guys reply too fast. cloerts, how does it run above 50? What is it like in the 90 range?

[renegade_xs11g]

I agree, that only helps figure out what is going, I've since replaced the vacuum module, bike is still in basement getting a make-over, plus being that i live in mid-michigan IT'S TOO DANG COLD OUT RIGHT NOW TO RIDE, But Spring is coming

[skids]

Spring is HERE. But yes...damn cold out there. Too cold in the garage to do the final drive conversion.

[fredintoon]

Spring is a coily metal thing

Hi Skids,
here on the prairies there is no spring.
The time between the waxing equinox and the mid-year solstice is called slush, dust, gravel & pot-hole fixin'.
Fred Hill, S'toon.

[DiverRay]

If it's not the advance, check the fuel line routing. If you have both lines "pinched" once the tank is all the way on, you won't be able to flow the fuel needed to really run. This can be caused by TO LONG A FUEL LINE.
Just my guess.

[HobbyMan]

You can really tell if your flow is good by opening all of the float bowl drains and setting the petcocks to prime. Check the amount of fuel draining out of the bowls. They should all be about the same. Make sure the engine is not hot when you do this. I don't want to be resposible for a burned bike.

[skids]

Well, yes and no. Prime flow will let you know if the line is kinked or the inline filter is clogged. I see he has a model G with auto-petcocks. That being the case, it is possible that the vacuum line is crapped out of maybe the diaphragm leaks badly. Sometimes the oring of the plunger can stick to the seat. You can test that one by disconnecting the vacuum hose from the manifold nipple and suck on the end to open its flow. If someone has sealed the tank, the petcock filter tower can get clogged (or with rust) and if that is the case, I suspect that Prime setting would show reduced flow, just as Run (or is that "On" on the standard?) would.

Originally posted by HobbyMan
You can really tell if your flow is good by opening all of the float bowl drains and setting the petcocks to prime. Check the amount of fuel draining out of the bowls. They should all be about the same. Make sure the engine is not hot when you do this. I don't want to be resposible for a burned bike.