Popping anyone?

[SPLINTER]

OK, after taking off the carbs for the 3rd time to clean a verify cleanliness of of all orifices, I'm still getting a ever so light popping on my left side bank. The mixture screws are out 3 1/2 turns as per a 63 yo Honda mechanic I talked to a while back. I just don't see those babies be clogged or dirty. This is a 82 Prolink, so the jets are removable. Ran the .013 wire on all again as well as carb cleaner and high pressure compressed air. Blew everything that could be blown. Still, the popping has not disappeared. Could this be an electrical issue?

[daves79x]

Is the 'popping' more of a mild backfire through the carbs? That's the sign of too tight valves, valves with carbon in the seat, or just plain burned one. Has your bike sat for quite a while (maybe years)? Very common to hear this if that is the case. Run the bike through several heat - cool cycles and see if it improves. This is provided you've checked valve clearance and found them to be OK.

But also could be still the carbs. Lots of discussion about float level here recently - you sure everything good there?

Otherwise, did you check/tighten all your plug caps and coil connections? Might find something there.

Dave

[SPLINTER]

Hi Dave! good to here from you again. Sounds like a periodic mis fire. Yo can put your hand close to the exhaust and feel it every 10 sec or so. The bike ran wonderful last year and only sits for a couple of weeks at a time. After three weeks of sitting, the problem started. Dave, I would bet my life on it...the carbs are clean. Its not like this bike sat for a long time. Valves all sound fine and I have set the mixture screws at 3 1/2 turns out. The floats I left the way they were. When it ran fine. To the eye, they appear mechanically correct. As to your last point, I did not check those, but will. I could see if this bike sat for a long time and the carbs could get super dirty...but this baby has been humming for some time now.

[ajs350]

Splinter
I had symptons just like yours and cleaned my carbs many times only to find it was the float levels being too low. See the following "missfire and hesitation" thread.
viewtopic.php?f=25&t=6893
Ross

[SteveG]

.......... Valves all sound fine...................

Hello!

Does that mean you don't hear them? (Tight?) Or you hear them clacking? (Loose?) Have you personally set them?

Many searches on the site reveal you want to set them to the loose end of the margin, i.e. .005. There you will hear them a little. Tight valves may sound good (quiet), but are death for the motor (burned valves / poor running).

Good Luck!

Steve

[SPLINTER]

Splinter
I had symptons just like yours and cleaned my carbs many times only to find it was the float levels being too low. See the following "missfire and hesitation" thread.
viewtopic.php?f=25&t=6893
Ross

Ross, this is one thing I did not check. The float levels. I was doubtful they would have changed since the last time the engine ran fine. Looks like I'll be removing the carbs yet again and checking/adjusting the floats. I take it this would produce the popping? Does the float have to be level when the tab just touches the plunger or should it be level when it seats?
The popping I'm getting is more noticeable at idle. just every so often, what sounds like a misfire or pop. Seems to lessen once the engine heats up, but never really goes away. During hard acceleration I also noticed a couple of flat spots as the speed is increasing.
OK, before I go for the gusto, I'll wait till the day is over to see if any other suggestions are forthcoming as to the probable cause of my condition. Thanks to all again for the steady suggestions.

[ajs350]

Splinter
I set the float level to 15.5mm using the Honda tool. The tab should just be touching the plunger, not compressing it. This is where I went wrong. I was compressing the plunger somewhat so that when I removed the tool the float was pushed down leaving the idle jet starving for fuel which produced my misfire.
Ross

[SPLINTER]

OK now...lets see...with a rise of hands, how many agree that this can be the cause of the misfire? Just curious.

[daves79x]

I think all we're saying is that this is one verifiable cause of what you are describing. I know you are trying to avoid another engine tilt, so pull #6 bowl on the bike and check the float - easy enough to do. That'll see one at least. In Ross' case, most all of his were too low.

I'm kind of confused with the statement "I was doubtful they would have changed since the last time the engine ran fine". If the engine ran fine, what exactly were you trying to fix by cleaning the carbs? You may have mentioned this before - I can't remember. Or, taking the comment the other way, just exactly when did the bike last run fine?

Let us know what you find.

Dave

[SPLINTER]

Dave, I appreciate your input and patience. The last time the bike ran fine was last Fall. Then it sat for at the most, a couple of weeks and back on the road again, then another couple of weeks and on the road again. 3 1/2 weeks went by and the problem started. All indicators were to clean the carbs. So, thats how the process started. I didn't think that the floats would suddenly have changed just by cleaning them. Therefore my statement. I will check the outer bowls (floats)tonight.

[Mike Cecchini]

OK now...lets see...with a rise of hands, how many agree that this can be the cause of the misfire? Just curious.

Hand raised here. With the carbs in the position shown in the pic......and the tab just touching the plunger is not what the manual (or I) say how the floats should be checked.

Imo........the carbs need to be tilted back just enough (circa 5--10 degrees) to where the float lever tab touches the plunger and
closes the valve by this (ever so light) pressure.......then check for the right float height (15.5 mm).

$.02

[SPLINTER]

Interesting Mike. Lets see if we can get a consensus here.

[oilheadron]

That's true Mike IMO. I just turn mine upside down (so that gravity is holding the valve against the seat) and hold the float by both pods so that it isn't cocking on the float pin. And then, of course, take the measurement with the float tang just barely contacting the valve pin.

[Mike Cecchini]

That's true Mike IMO. I just turn mine upside down (so that gravity is holding the valve against the seat) and hold the float by both pods so that it isn't cocking on the float pin. And then, of course, take the measurement with the float tang just barely contacting the valve pin.

Also, check both floats. I found many of mine were right on one float.......but off on the other float.

Both floats should be 15.5mm..... not just one.

[daves79x]

Either way works just fine - as long as you are not depressing the pin.

Dave