Rebuilt CL175 - Won't idle, runs rough.

Hi all,

Last year I unfortunately blew a hold in one of the pistons of my CL175. Have just rebuilt the top end, new pistons +0.50 rebore & new valves.

Started the engine up & she runs. Have been going through the break-in routine however there's a few issues that I'm having.

Main issue is that the bike won't hold an idle. Have set the the mixture screw on the carb to spec and once the bike's kicked over it will run & idle correctly for about a minute or so then it will slowly drop in revs and cut out. This will also happen when I'm slowing down for a stop sign/traffic light etc. I can keep it at idle speed by applying slight throttle. It seems that the idle screws aren't making any difference at all. I can't seem to raise or lower the idle by turning them.

Second issue is that the bike doesn't seem to have any low down power. It will ride okay until about 3-3500RPM where it will hit a powerband & take off. I'm confident my timing is correct however I'm wondering if it could be an advancer issue? Also been told that this may be normal for a freshly built engine.

Any thoughts suggestions appreciated! Would rather try do what I can myself before consulting a professional.

Cheers!

Rebuild is a loose term. Can you tell us what exaclty you did?

About the advancer... Take it off, disassemble it complete and assemble with some grease. That'll do it.

Timing could definitely be a culprit. Verify timing and compression with a light and gauge before continuing to mess with anything.

That said, the choke is off, right? ;D

Sorry for the late reply guys.

Rebuild wise I had a +0.50 rebore, new pistons & rings & new valves.

I think I may have found the culprit. Pulled the advancer, it's buggered - won't open or close smoothly at all. Have ordered a new one to be safe. Will update when I know if it fixes the problems.

The old ones can usually be cleaned up. Might be worth a try.

Sonreir said:

The old ones can usually be cleaned up. Might be worth a try.

Click to expand...

Tried the best I could! Unfortunately the metal around the centre tube thing (?) is chewed up. Was cheap enough to buy a brand new one thankfully.

The advancer may be sticking, however....try loosening all the adjustment bolts on the cable from the handgrip back to the carb body to ensure the slide is making a hard stop on top of the slide screw. I would start with the slide screw to be set at 1 turns in and don't go above 2 turns in.

redwillissuperman said:

The advancer may be sticking, however....try loosening all the adjustment bolts on the cable from the handgrip back to the carb body to ensure the slide is making a hard stop on top of the slide screw. I would start with the slide screw to be set at 1 turns in and don't go above 2 turns in.

Click to expand...

Thanks mate, I'll give that a go this weekend.

Cheers