problem with 21" mower

[EliteImpressions]

I have a mower with a honda engine that was used about 3 times a week for 3 years. Before the problem this mower would start on one pull everytime.

I used it for one lawn and it was fine but when I got to the next it would backfire once and thats it. If I tried to pull the cord right away it would act like it was already started (the cord would pull very easy with no resistance) Any tips would be appreciated.

[S DIAMOND]

Look at the valve cover. Is it dented in by chance? Did you run into an object that made contact with the valve cover? :walking:

[S DIAMOND]

If it is dented in, then it is possible that one of the valves could be held slightly opened. I have seen this more than once.

[EliteImpressions]

Yes,

It is dented in. How do I go about repairing that or is that for a professional to do.

[S DIAMOND]

Drain fuel and oil (for less mess). Tip mower up so you can access it easier (follow universal precautions when working; unplug the spark plug boot etc.) then remove the cover. Gently tap out the dent from the other side.

Examine the valve assembly and make sure everything is OK.

Now, you will have to clean the old RTV sealant off completely and make sure you don't get any into the mower. You'll need Honda bond or an equivalent RTV sealant to reapply and let it cure overnight for best results. Follow the directions. It's really easy.:) Hope this helps some.

[S DIAMOND]

You didn't post any engine numbers, so I'm assuming you are speaking of a GCV model and not a GXV model? The difference will only be gasket material, I'm pretty sure. GCV will be RTV and GXV will usually be (example) a cork, rubber,or fiber gasket.

[EliteImpressions]

S Diamond,

Thanks for the help. Ill give it a shot tonight.

[EliteImpressions]

S Diamond,

I removed the cover and taped out the dent. I looked at the assembly and it looks intact but Im not really sure what I should be looking at. I put the sealant and let it cure but its still not working. Heres a pic if this helps any.

Thanks
Joe

[Phil G]

Sounds like you've got a valve issue there. Remove the spark plug, get a set if feeler gauges and check the valve/push rod gap. It is straight forward to do. Rotate the engine slowly to check the gaps. I would imagine one of the valves has no gap due to the impact on the cover. If it didn't stop when you were using it, it may have been damaged whilst in transit in your van. You're looking for a gap between the the push rod and the rocker. Check the manufacturers site, but to give you and idea the gaps should be in the region of 8 to 12 thou.
Don't be intimidated by this, it's a straight forward job to do.
Good luck, Phil :)

[EliteImpressions]

I didnt get a guage but I did pull the cord and watced the valves go. They both appear to be the same distance and work in the same fashion. The dent was on the right side so I made sure the right valve was working the same as the left. Still no luck. Im going to try the spark plug and if that doest work, Ill send it to the dealer.

Thanks

[Phil G]

I didnt get a guage but I did pull the cord and watced the valves go. They both appear to be the same distance and work in the same fashion. The dent was on the right side so I made sure the right valve was working the same as the left. Still no luck. Im going to try the spark plug and if that doest work, Ill send it to the dealer.

Thanks

No problem about the gauge. Just one check before you take to the repair shop. Rotate the crank slowly and when each valve is in the closed position (out the furthest) look to see if there is a small gap, or rock it in and out to feel any gap. No gap, no valve fully closing, a few thou' can make the difference. Although unlikely the possibility exists that the valve stem could be damaged and stopping it from seating fully. Worth spending two minuets to save $40 to $60.
Good luck Phil :)









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[S DIAMOND]

Joe sorry to hear that didn't fix the problem. I could not see anything out of the ordinary with your photo. If you do not feel comfortable adjusting the valve lash, then do take it in for further inspection. It is possible there are other related problems involved.

You may have done this already, but if you have not, remove the plug, and with a small flash light (mag light, etc.) examine the piston. I don't think this will be a problem, but examine the piston top for any possible damage and or pieces in the cylinder.

Your clearance on this engine, as most Honda engines, is:

IN: 0.006" +/- 0.002" Metric: 0.15 +/- 0.04mm
EX: 0.008" +/- 0.002" Metric: 0.20 +/- 0.04mm

It's not difficult to set and or inspect the clearance, but you will need a feeler gauge and will need to set the piston at T.D.C. of the compression stroke. Honda has made it a little easy by placing alignment marks on the Cam Pulley to help in this process. But if don't feel comfortable doing this, no problem. P.M. me if you want a "walk-through," Keep us posted. :)

[Happy Frog]

Nice helpful posts S DIAMOND.
You are an asset to this web site. :drinkup: