Losing power at 65

**bgibbscmx250** · 12-12-2010, 03:14 AM

So when I am driving I find that when I hit 65 on the highway I start loosing power and it jerks a little and I lose speed until I let off the gas and then gun it. Also every now and then I get a studer in the engine while cruising. I don't lose speed but it feels like it wants to back off. Any suggestions. Thanks!

**Buickguy** · 12-12-2010, 03:19 AM

What year Rebel?

**bgibbscmx250** · 12-12-2010, 03:24 AM

I'm running a 1985

**Buickguy** · 12-12-2010, 03:47 AM

If you could give a bit more information like the last time the valves were adjusted or any recent things you've changed. The more info the better the folks here will be able to reason it all out.

My guess:
It sounds like a fuel delivery issue.
Possibly the tank screen with enough crud on it to slow the fuel flow.
Possibly a dirty carb.
Possibly the sediment bowl on the petcock with dirt in it.
If you have an inline gas filter put in that could be dirty.
Possibly a venting issue. The '85 -87 vent through the gas cap unless its a california model.

**shadetree** · 12-12-2010, 07:04 AM

Mine did something like that a while back and found the fuel line was bad.

**Guba** · 12-12-2010, 11:24 AM

I also have to go with fuel delivery issue. I had similar results when my fuel line got vapor locked with a loop seal, the result of adding a fuel filter that was too long.

**jax** · 12-12-2010, 06:50 PM

I have had the fuel line come apart on the inside and when you get going fast enough the fuel line will get a blister on the inside and restrict the flow of gas. It was a bummer to find but all I had to do was replace the fuel line and all was good. It took about 2 weeks to finally find the problem.
The other one I had was I was using a 49 state tank with a Ca. gas cap, The Ca. gas caps don't have a vent so the tank was going into a vacuum when I was going over 65.
I put a vented cap on the tank and all was well, went as fast as I wanted to go with no starving for fuel.
good luck

**Twister** · 12-13-2010, 04:11 PM

Next time it does that (with a full gas tank), pull over, take off the gas cap for a second, put it back on, take off, if it doesn't lose power for a few miles it's probably your gas cap is not venting or you have a loop between your petcock and your carb.

If it still loses speed right after taking off and replacing the gas cap, I can bet you a dollar is you larger jet.

Before you dig in the carb make sure your air filter is clean and try seafoam @ 1 oz per gallon of gas. The other thing you might try is to "starve" the bike. (With the bike parked and idling, turn the petcock OFF give it a bit of gas 2000 rpms or so, when the engine I'd dying give it lots of gas 5000 rpms or so) that sometimes pulls particles thru.

But if you want a clear shot, pull out your carb, clean put it back together and go for a ride.

2 cents.

**bgibbscmx250** · 12-14-2010, 12:15 PM

Thanks for all the replies. Here is what I've got

Carb is cleaned. Had to clean it for emissions.
I have an inline filter for my fuel line.
I have a new fuel line installed
My tank is so clean you could eat out of it. No Rust what so ever.

Now does anyone have a pic of what a CA gas cap and the other cap look like. I'm almost certain this might be my issue. The cap that was originally on there had a long extension on it feeding into the tank. The cap I have now does not.

Also my other issue is when in 5th Gear and moving at 65 I get nothing. What I mean is if I give it gas my engine just revs and I don't go faster. Like the throttle isn't catching. Any ideas there? Thanks again for all the info

**Buickguy** · 12-14-2010, 02:18 PM

Take a look in my Rebel album. I've got pics of what the vented cap looks like.