Small Engines (Lawn Mowers, etc.): Honda Mod# HRX217HXA, hrx217hxa, honda mower

Question
Re: Honda lawn mower Model# HRX217HXA

Engine Model# GJAAA-1244554 which is stamped on the engine.
(it is in the Honda model# GCV190 engine family)

I have recently received one of these mowers for repair, it does the same thing as discussed in the conversation below, only the one I have is backfiring through both the carb and exhaust, the smoke is blue-ish (oil). It is NOT WATER in the gas, the first thing I did was clean out the fuel system - No Difference. It may be a timing issue, the Honda GCV190 engine has an internal timing belt (Why would anyone put a TIMING BELT inside of a small engine bathed in oil?) and possibly it jumped timing. I have not attempted to fix this yet as I am waiting for the service manual for this p.o.s. engine.

My question for you is; Since the following conversation is so old has anyone else determined what the cause is, of this hard starting, stalling, backfiring issue? To me it sounds like timing.

Thank You
Steve

In reference to the following conversation with Tom dated 8/18/2008:

Note: the following conversation is not with me.


Small Engines (Lawn Mowers, etc.)/Honda Mower Engine

  
Expert: Tom Adinolfi - 8/18/2008

Question
Hello, my HRX217HXA mower with a GCV190 engine would not start yesterday. The engine would make popping/backfire sounds thru the carb. Occassional white smoke from the muffler. I replaced the spark plug today and nothing changed, still won't start. The engine ran just fine last week. The mower is only 4 years old and has had yearly oil changes. Not sure what to do next.



Answer
Any chance it was left where rain could have got into the tank? Sounds like water in the tank to me. If there is even the remote chance water could have somehow, someway got into the tank, I would empty the tank, remove the carb bowl and dump that too, and do a fresh refuel....That white smoke is telling me there is water in the muffler. If it is in there It's very well  in the tank too.    Tom

Answer
Have you pulled the valve cover and checked the valves?  All 4 cycle engine exhibit valve overlap at one of point at top-dead-center (TDC).  You can insert a drinking straw into the spark plug hole and feel when the piston comes to TDC.  You should be able to rock the flywheel back and fourth and either see or feel the valve overlap (both valve will be open slightly).  This technique will ensure timing is correct.  At one factory school they purposely mis-marked the timing mark on the cam.  I was not the first to get the engine assembled but I was the first to get it running...by making sure the valve overlap was present at TDC.

This sounds complicated but it is very simple and the best way to check timing (mechanical) with out dis-assembling the engine.
Eric