Quick question about engine shaking--77 Westy, Dual Webers

[thesamwise4]

Greetings, all.

I'm not sure that this issue has become worse recently, but maybe I've just started playing a little more attention to it.

When I start my engine, I notice that it does a bit of shaking/bucking--enough that I can feel the bus kind of rocking around a little from the front seat. It goes away as the bus warms up.

To give you an idea: If I sat a nearly full glass full of water on the engine, it would probably spill but not fall off.

If I drive it for ten minutes or so and then stop to get gas, it starts up again with very little/no shaking.

Obviously, this is a starting from cold (even when it's hot outside, as it is today in DC) issue.

This is what I'm concerned about: I seem to recall reading somewhere (a while back [I can't find this post now, of course]) that this may be a sign that the carbs are not getting enough air and need to be adjusted. Any thoughts on this? Is it normal for the engine to buck around a bit at start-up?

If you tell me that it's not an issue and it's just the bus warming up, ok--great to hear. I just want to make sure that I shouldn't be concerned about it.

[satchmo]

Probably not enough fuel rather than not enough air. IIRC, Webers don't have chokes. If you don't have chokes, you are missing the cold start fuel enrichment the engine requires until it is warm. Therefore your cold starts will be a little on the lean side and a bit slow, so the engine will buck around until it is warm. The only solution is to keep the rpms up a while after starting (keep your foot on the throttle) until the engine is warm and the idle has smoothed out.

Tim

[vdubyah73]

give it an ignition tune up before you touch the carbs. most carb poblems are really ignition needs tune up. daily driver or are you just waking it up for the summer? i have a pair of weber icts on my bus. runs great, in summer time i can start it and drive in the time it takes to release the brake and put it in gear. it'll run by itself in about a minute or so in freezing weather, the colder the longer. the colder the lower the cold idle. i've marveled at how slow it chugs over when it gets into single didgits or colder. i let it run and go finish my coffee. i've never owned a more reliable vehicle. i've always had old iron, let the wimmen have them modern cars.

[72Hardtop]

Greetings, all.

I'm not sure that this issue has become worse recently, but maybe I've just started playing a little more attention to it.

When I start my engine, I notice that it does a bit of shaking/bucking--enough that I can feel the bus kind of rocking around a little from the front seat. It goes away as the bus warms up.

To give you an idea: If I sat a nearly full glass full of water on the engine, it would probably spill but not fall off.

If I drive it for ten minutes or so and then stop to get gas, it starts up again with very little/no shaking.

Obviously, this is a starting from cold (even when it's hot outside, as it is today in DC) issue.

This is what I'm concerned about: I seem to recall reading somewhere (a while back [I can't find this post now, of course]) that this may be a sign that the carbs are not getting enough air and need to be adjusted. Any thoughts on this? Is it normal for the engine to buck around a bit at start-up?

If you tell me that it's not an issue and it's just the bus warming up, ok--great to hear. I just want to make sure that I shouldn't be concerned about it.

Are these IDF's? If so, welcome to the club. Webers require a dance with the foot, so to speak when starting from a cold start (cold weather). The colder the weather the more the dance. Perfectly normal. One would have to be a masochist to set up Webers with the enrichment circuits operating.