reving up without warning

[rizzo4u2]

would the cdi ignitor cause my bike a 79 to rev up on its own, rode 15 miles everything was fine come to a light the bike tached up to 1800..2000rpms on its own,before i left it was fine, had carbs checked looks good, cleaned all the connections on this bike when i first got it, a couple months ago, let the bike run it tachs at 1000rpms for like 15 min and then starts to climb on its own, has any body heard of this one or is it in the electrical system

[randy]

Mike,

Could be you need a carb sync, or your idle is just set too high, and when it warms up it rises.

There may be someone nearby that can help you. Are you in Northhampton, Luzerne or York County? (there are 3 Hanover's in PA). I'm in Monroe.

[mro]

Just get the 79' running?
Sounds like out a synk carbs... (as randy said)
or maybe a vacuum leak.

If a cylinder started out a little lean,
it will be more so as the engine warms up which can raise the RPM.

Can be lean from a vac leak and at under 3K pilot needle adjustment effects fuel/air mix too.

A restriction (like a little debris in the jet that's inside the carbs fuel bowl) in the idle/enricher circut can cause a lean condition.

No cdi on the XS, called a TCI


mro

[mro]

Very unlikely to sync carbs properly without a vac sync tool.
Can be gotten close by “eye” but not close enough to run right.


mro
BTW, welcome to XSland
Got any pics of your ride???