Carb sync

[alexanderfitu]

Hi all

I did my carb sync recently.

Two things came to mind.

1. It was very very hard to lock the locknuts up without adjusting the balance.

2. I set the idle to 1000rpm, went for a long ride today and after a fast bit in the road my idle rpm shot up to 2000rpm and stayed there.

I got back and hooked up the vaccum gauges again, suspecting that a locknut was not done tight enough, but they where all still balanced. I set the idle back to 1000rpm and all was well.

Not sure what happened there, maybe the idle set screw moved?

[CYBORG]

Maybe...but I would look for a vacuum leak. re-tighten the manafold clamps. Good place to start

[alexanderfitu]

Maybe...but I would look for a vacuum leak. re-tighten the manafold clamps. Good place to start

I will double check. I did check with brake cleaner etc around the areas recently and no rev increase. All the screws are tight etc.

[robin1731]

re-tighten the manafold clamps. Good place to start

Do this with the engine at running temp. You can usually get another turn or more out of the clamp screw then. A good habit to get in to when putting the carbs back on any time is to retighten them once the engine is warm.

[RB]

Sticking slide, throttle cable pinch, vacuum leak, uhmmm...ah what else???

[jdvorchak]

Actually that sounds pretty normal to me especially if the bike wasn't really up to temp when you did the sync. GL's take a while to get up to temp, like 15 minutes or so just sitting there idling. I rebuild a lot of carbs and after the first test ride I often have to reduce the idle speed.

[alexanderfitu]

Actually that sounds pretty normal to me especially if the bike wasn't really up to temp when you did the sync. GL's take a while to get up to temp, like 15 minutes or so just sitting there idling. I rebuild a lot of carbs and after the first test ride I often have to reduce the idle speed.

I did really heat up the bike before doing the carb sync actually, a good 30 minute ride, then idled for another 10 minutes whilst I got the gauges etc setup.

If it doesn't happen again then I'm happy.

[jdvorchak]

Yep.. been there done that. Now the bikes I work on have usually been sitting for a few years. So I chalk it up to the bearings and everything inside, especially the carbs, got exercised and now it's running more efficient. Just my opinion but I've had it happen a few times and never had one again idled high.

[alexanderfitu]

Yep.. been there done that. Now the bikes I work on have usually been sitting for a few years. So I chalk it up to the bearings and everything inside, especially the carbs, got exercised and now it's running more efficient. Just my opinion but I've had it happen a few times and never had one again idled high.

Many thanks, Will keep an eye on it, but not worry.