Question guys!

[Jym777]

When I start it up cold #2,4,or 6 cyc will make a pop pop sound out the exhaust, when warmed up you hear nothing, is their a valve adj on these things? I was thinking air leak but it would still do it when it was warm if that was it? Any ideas? Appreciate any and all info! Jim..

[John Schmidt]

Yes, the valves are adjustable on these engines. I'd look at ignition on that side first, especially if you don't have extremely high mileage. I'm pushing 50k and have yet to make any adjustments to the valves although I've checked them twice.

[Jym777]

Thanks John, thanks for the info! I know it's on left side got my ear down at the tail pipes it's popping on the left side, have done valves on cars but not on one of these, do you know what the valve lash is on these? And how do you find tdc for each cyc, it only has 34000 on it! Appreciate your help! Jym..

[John Schmidt]

You really need a Honda shop manual, the valve adjustment procedure is outlined in there....including the turn of the engine for the next valve to be checked.  First move when doing it....pull all the sparklers.

[Steel cowboy]

Try some easy fixes first, I would look at the intake o rings, and the exhaust gaskets first. When the engine is cold the gaskets and Orings don't seal as good as when everything is warmed up and expanded. Make sure the acorn nuts are all there and tight. I said tight not torqued down. I found the acorn nuts on mine were loose and I had lost one already. Easyer than a valve adjustment.

[Jym777]

Appreciate all the info guys, the "O" rings were changed about two months ago when I rebuilt the carbs and the exh gasket about a year ago, but I'll have to  see if they are tight. Thanks for the reply!

[Grumpy]

Also look at the clamps on the rubber connectors on the intakes, also could be some partially clogged slow jets, dump about 1/2 a can of Berrymans B12 and putt around with the bike at slow speed for a while. Running at high speed it runs off the high speed circuit and does not use the slow jets.