Stumbling

[HalfCentury]

If you cut off the end of the wire at the plug cap and reinsert, you have fresh wire. It's so simple. I would recommend that before buying new wires all around.

Having never done this required watching a demo on youtube. You are correct that its the easiest thing to do in the debug process. After chopping off 1/2 to 3/4 of an inch, the wire is nice and shiny silver at the cut point. Screwed the clean end back into the cap and twisted until tight.

Took it out for a drive and I could tell that the stumble is still there. Pulled the plug and #2 is fouled. There is also a fairly strong gas smell when pulling into my driveway. My guess is that #2 carb has something wrong that shoves too much fuel into the cylinder.

Another item for the group to know is that I removed the YICS bolt a couple of days ago and some dark liquid poured out of the hole. The quantity was a couple of tablespoons. I cleaned out the port and reinstalled the bolt. I am going to remove the bolt again to see if the fluid in the YICS port is an ongoing problem.

[HalfCentury]

There is raw gasoline in the YICS port. Enough to make a wet spot on a paper shop towel. I cleaned this port two days ago so the raw gasoline is new.

The oil level was 1/2 quart low. It appears to be burning some oil.

[skids]

Sorry if this was covered already, but you might want to compare the amount of fuel from the No 2 float bowl with others.

Although this has nothing to do with level of fuel in the bowl, I would think that if the pilot air jet or its passage was plugged, the idle circuit fuel supply would be richer. Think of sucking soda from a straw with a hole in it.

[Schming]

Pull the Carbs

There is raw gasoline in the YICS port. Enough to make a wet spot on a paper shop towel. I cleaned this port two days ago so the raw gasoline is new.

The oil level was 1/2 quart low. It appears to be burning some oil.

If I may, You need to pull your carbs and clean ALL the passages and reset the float heights before the raw fuel dilutes your crankcase oil which will lead to a spun bearing.

Also valve shim adjustment is a critical component in the tuning process, 'cause without the engine breathing at max capacity, the carbs can't be tuned to theirs.

[HalfCentury]

If I may, You need to pull your carbs and clean ALL the passages and reset the float heights before the raw fuel dilutes your crankcase oil which will lead to a spun bearing.

Also valve shim adjustment is a critical component in the tuning process, 'cause without the engine breathing at max capacity, the carbs can't be tuned to theirs.

Hello Schming

Thanks for chiming in. The valve clearances were check, adjusted and re-checked. I have the before and after map of the shims in a notebook.

I agree that the carbs will have to come off and be looked at. Its a shame that 3 of 4 appear to be good and one is recalcitrant. While I have the tank and carbs off, may as well re-check the valve clearances.

Do I recall correctly that one of the regular posters had a theory that one of the 4 carbs is the "evil carb"? Was it carb #2?

[motoman]

Hello Schming

Thanks for chiming in. The valve clearances were check, adjusted and re-checked. I have the before and after map of the shims in a notebook.

I agree that the carbs will have to come off and be looked at. Its a shame that 3 of 4 appear to be good and one is recalcitrant. While I have the tank and carbs off, may as well re-check the valve clearances.

Do I recall correctly that one of the regular posters had a theory that one of the 4 carbs is the "evil carb"? Was it carb #2?

It is carb #3. While bike idling, fuel bowl levels need to be ALL identical at 3mm below bowl mounting surface.

[skids]

If I may, You need to pull your carbs and clean ALL the passages and reset the float heights before the raw fuel dilutes your crankcase oil which will lead to a spun bearing.

Also valve shim adjustment is a critical component in the tuning process, 'cause without the engine breathing at max capacity, the carbs can't be tuned to theirs.

Hey Schming, that winking emoticon is reserved for Motoman!!!

[motoman]

Hey Schming, that winking emoticon is reserved for Motoman!!!

Thanks Sid, but I pretty much just use it if referencing to an issue that I've already resolved a long time ago myself............in hopes it helps someone else.

[BA80]

Thanks Sid, but I pretty much just use it if referencing to an issue that I've already resolved a long time ago myself............in hopes it helps someone else.

[motoman]

No surprise......figured that was comin' from ya'........sooner than later.

[HalfCentury]

If the collective would speculate, what should I look for with a an overly rich carb #2? I am thinking if the air jet is plugged, that could cause a rich condition. Yes? No? What else?

[motoman]

If the collective would speculate, what should I look for with a an overly rich carb #2? I am thinking if the air jet is plugged, that could cause a rich condition. Yes? No? What else?

Schming's post #19 would be a good start.

[HalfCentury]

Schming's post #19 would be a good start.

ok. will do and report back.

[HalfCentury]

I performed a dry compression test. 130 PSI across all four cylinders. I guess this means that a second appointment with the carbs is in my future. I much prefer a second appointment with the carbs than appointment with the piston rings or valves.

[skids]

One more thing. Is your exhaust system in good shape? Strange things can happen when a baffle is shot.