Popping out exhaust

[pidjones]

What I would personally do, is open the idle screws on the offending side by 1/2 turn each. After that, try to ignore it for a while and it will stop bothering you soon.

[cfairweather]

The air cut valve only costs about 10 bucks and it is easy to replace and maintain. It helps eliminate popping when you decelerate. If it was $100.00, I might consider bypassing it, but for $10.00, I will keep it in place.

[tory]

Thanks all, I did in fact swap a lot of components from other carbs. Mainly because they where new. Including air cut off and honda needle and seats. Popping is much worse cold and tempers down when warm.

[gltriker]

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[ericheath]

Going to toss this out there even though you said you checked valve adjustments. Mike Nixon and the infamous Cliff are big proponents of looser valve adjustments. Looser by 0.001” over stock. Adjusting valves is done on a stone cold engine. How much is a “slight resistance?” Kind of vague. It might be worth loosening the valves just a bit. In my experience, when valves have been just a little bit too tight, the sound at idle is almost a wet sound like a water droplet falling into water.

[gltriker]

Going to toss this out there even though you said you checked valve adjustments. Mike Nixon and the infamous Cliff are big proponent of looser valve adjustments. Looser by 0.001” over stock. Adjusting valves is done on a stone cold engine. How much is a “slight resistance?” Kind of vague. It might be worth loosening the valves just a bit. In my experience, when valves have been just a little bit too tight, the sound at idle is almost a wet sound like a water droplet falling into water.

[tory]

Thanks. Did the valve clearance in January in Michigan. Pretty sure she was cold. Lol. I do tend to lean more to the loose side than right. However it did not help.

I will pull the carbs back off next garage time I get.

[BikeMaine]

Here to follow along and hopefully learn something about this popping noise.

[tory]

With the warm weather I did get about 100 miles on it. Still pops at idle and slightly breaks up at 4200 rpm. But quickly gets past it and pulls good and hard.
Re reading here and considering the air cut off goes to the offending carb, I should look that back over. Could i have installed it wrong or backwards? Or a leak in the line or seal? I will have to get back into it.

[Whiskerfish]

I have not reread the whole thread recently but popping in the mid range from my experience is very often a hanging CV slide. If one is hanging it will cause a lean condition on that one jug. When I build a rack while I still have them on the bench I use a shop vac to create a vacuum in the intake elbow of each carb then manually open the throttle to see when the slides go up and down.
Just a thought

[tory]

I have not reread the whole thread recently but popping in the mid range from my experience is very often a hanging CV slide. If one is hanging it will cause a lean condition on that one jug. When I build a rack while I still have them on the bench I use a shop vac to create a vacuum in the intake elbow of each carb then manually open the throttle to see when the slides go up and down.
Just a thought

Good tip with the vacuum. The miss fire at 4200 is minor, but the bigger issue it the popping out the right side at idle.

[tory]

So I spent some time this weekend again on it.

Verified compression is good on all 4.

Replaced condensor, cleaned all connections and grounds

Eliminated air cut-off valve.

Cleaned (again) and replaced low speed jet in front right carb. (This seems to be the offending cylinder)

I have gained no ground. Riding the bike it seems to have decent power and only has a slight breakup at just above 4000 rpm. But pops like crazy out right side at idle.

[tory]

Is it possible I could have the right side timing belt off 1 tooth?
Compression is good, so valves did not hit. Also wouldn't that effect both right cylinders?

[Whiskerfish]

If the comp is good I doubt you are off by a tooth but it is a relatively easy check if it would help you get it off the list.

Dos the idle drop work on the # 1 carb?

[cfairweather]

On the carb of the offending cylinder, please turn the idle jet screw in, even to the point of being completely seated. This is to troubleshoot the issue. If the popping stops, you have a bad carburetor or one that will have to be adjusted differently due to the seat being damaged. Let me know what happens as you turn the screw in. Listen carefully.