Question About Carbs

[Venturous Randy]

Number 2 appears to have melted aluminum bits on the electrode. That can't be good.

 

 

It looks to me like there is a lot of anti-seize on the threads and I wonder if that may be some left over residue?

RandyA

[Prairiehammer]

It looks to me like there is a lot of anti-seize on the threads and I wonder if that may be some left over residue?

RandyA

 

OK, I'll give you that excessive aluminum anti-seize might manifest itself on the electrode, but I personally do not see any anti-seize on the spark plug threads.

[Neil86]

One issue that is common on older Ventures are vacuum leaks on the YICS chambers....used on 83-85 the plastic chambers that sit above the front cylinder head.

Are yours still in service (connected to intake ports) and if so have you ever tested each hose

and chamber for a vacuum leak (using a MityVac etc).

[Venturous Randy]

OK, I'll give you that excessive aluminum anti-seize might manifest itself on the electrode, but I personally do not see any anti-seize on the spark plug threads.

 

You may be right, but to me, the shiney gray threads look a lot like my threads when I remove them and they have anti-seize on them. Maybe the OP will let us know.

 

One issue that is common on older Ventures are vacuum leaks on the YICS chambers....used on 83-85 the plastic chambers that sit above the front cylinder head.

Are yours still in service (connected to intake ports) and if so have you ever tested each hose

and chamber for a vacuum leak (using a MityVac etc).

 

I just did a thread on plugging the YICS system and suggest anyone that has not removed their entire YICS system should do so. I suspect there are a lot of MK1's running poorly and have difficult tuning because of the YICS system. With 30 year old hoses and a big plastic box that cracks, it all needs to come off.

http://www.venturerider.org/forum/showthread.php?t=86100

RandyA

[Pegasus1300]

I got mine about a month ago from Vessel for 30.00 for a #1 #2 #3 motorcycle set. set # 900/KIT-P123

http://www.vesseltools.com/

This is the oldest screwdriver manufacturer in Japan and it used to be that the only decent hand impact driver came from these guys. Mine is 40 years old and still works great.

[Pegasus1300]

For anybody who reads this this thread one trick I learned from this forum is to use a pair of wire dikes and grab the head of the screw and twist. I have used that trick on many screws now on several bikes and it works like a charm.

 

I have never tried that. I usually use a small pair of vise grips. Of course the screw has to be replaced at that point but then if its that buggered you would anyway.

[jbkieser]

Generally on the pilot screws I have an initial setting of 2.5 turns out from soft stop. Looking at the plugs and thinking that a couple might be running lean, I added .5 and .25 turns to two carbs. Need to run the bike to see what the results might be.

 

I have used anti-seize on the threads and in a couple of cases got a bit on the tip of the plug. I am a little concerned that I'm running the plugs too lean and getting some metal on the tips and that's why I want to enrichen them a bit to be on the safe side until I get a better handle on things.

 

I agree that I need to work the pilot screws, but in my preliminary efforts I don't see much, if any, change as I turn the pilot screws. As you suggest the pilot circuit may be problematic. I'll need to research this further.

 

I do see where I can blow though that circuit from within the airbox and after removing the diaphragm assembly and the pilot screw assembly. Spray the passage generously with carb cleaner and follow with compressed air. Then repeat. I suspect that this may ultimately lead to me pulling the carbs again to get a better job done. I didn't specifically attack this area when I had the carbs on the bench.

 

Also I'm wondering if the coasting enrichment valves might have some bearing on my issues. I didn't service those when I had the carbs off and now I'm wondering if I should do that. I don't know how they might create issues.

 

The YICS is not a issue in that I removed that entire assembly when I had the carbs off. I plugged the two inner ports with appropriately sized gas line hose plugged with a bolt and plenty of black RTV to seal the bolt into place. The two outer ports have cheapo caps which I will replace with something more substantial, but presently they don't leak.

 

I used propane to try to detect intake leaks all around the carbs, the mounting boots and the old YICS ports and nothing was indicated. I do note that when I pull the carb sync port cap on #1 (my problem child cylinder) and place my propane source near it while the engine is running, then I get an appropriate increase in RPMs.

 

We're traveling for a couple of weeks and I'll need to pursue things later. In the meantime, thanks for the feedback.

 

Jan in Phoenix