Small garded tiller won't start

[radojica]

Hello,

I was recently tilling my garden for about 20 minutes, and in that 20 minutes tiller stalled 2 times and the seconnd time it stalled I stopped the work,
brought it back to the garage and checked fuel and just visualy. I started it 3rd time and it runned for 5-6 seconnds and stopped.
After that I repeated it couple of times and still stopped after 5-6 seconnds.
After couple of times it won't start at all, so I assumed the carb...
I cleaned carb even though it looked cleen with carb cleaner thoroughly.
After carb cleaning still no go, after couple of times it won't even start.
It just starts with starter spray for 0.5 seconnds and dies.
I changed sparplug, checked for spark... everithing ok.
I then checked valve clearance, it was off maybe 0.002 on the intake... I adjusted clearance as specified to 0.006 intake 0.008 exoust.
Still no change...
Finaly today I removed head and checked valves, no major carbon buildup, nothing special, valves are sitting "fine" (I'm not an expert).
I checked compression with my finger... I can hold air when I try my best... does this mean that it looses compression trough piston rings
and is that common reason for not starting?
How it is possible that it starts with starter spray if compression is so low?

The engine is OHV, some Chinese Honda replica... not many working hours (I've bought it used, but seemed decent)
PS. I tested carb on my lawn mower, it works with it...

Sorry for long post and for my bad English.

Thank you in advance for any suggestions or opinions.
KR,
Radojica

 

[bertsmobile1]

Find the magneto coil and remove the kill wire from the coil
Attach another piece of wire to the terminal make sure it is insulated & not touching anything.
Start the tiller
ir it runs fine then you have a problem with the kill switch
Ground your extra wire anywhere to stop the engine
I have no knowledge of the tiller you are using so do not know how many kill switches are on it or where they are so you will have to trace back the kill wire to check all of the switches.
Long posts are good.
The more you tell us he more we have to work with,
Good luck & good cropping.

 

[radojica]

Hello bertsmobile1,
Thank you for your suggestion.
I've checked the kill switch, there is just one. I measured ressistance with mOhm-meter (I have a lot of engineering instrumentation) it seems pretty decent.
I anyhow bypased it as you've suggested and no difference. I had high hopes that it is something simple as this, but no luck.
One other thing, when I start it with starter spray and quickly push governor rod to max it stays on but runs very very poorly, like it is going to die any seconnd, I didn't want to screw something up so I stoped it after 10-15 seconds.

 

[bertsmobile1]

So we have ruled out the carb & the coil switch.
That only leaves us with the governor , the fuel supply or the control cable.
In cases like this I like to push the spacers out of the air filter housing so I can fit the carburettor without the air box fitted.
Then start the engine using carb cleaner, not starting fluid which is too volatile for petrol engines.
Once the engine starts give it short shots of carb cleaner to keep it running and watch the governor
As the engine speeds up when the carb cleaner is sprayed into the engine the governor should close the throttle butterfly and as the engie is slowing down towards a stop it should open the butterfly wide open .
If not the governor is not adjusted properly.
Also after starting I like to put my finger on the governor arm or throttle butterfly and work it manually
If it does not respond the the position of the butterfly then there is a fuel supply problem.
IT could be bad fuel or not enough fuel.
The other thing I do is fir an inline spark tester that glows red so I can see if the spark is breaking down at speed
And of course all this is done with a known good plug that has been warmed up in another engine .
Easy for me becaue I have all this stuff laying around and plenty of old fuel tanks so I can hook one up with fresh fuel in it to rule both a dirty tank or bad fuel out.

 

[radojica]

Hi bertsmobile1,

I resolved the issue.
I've tried starting with carb cleaner and pumping carb cleaner every few seconds, and as I sprayed the engine speeds up and governor responds by closing butterfly, and shortly after, starts opening it again. So that meant good governor operation, by my opinion. But still shutting down without spraying carb cleaner. And when I pushed governor arm to the max it runned on fuel but poorely (as I mentioned). So it got me thinking...why is it not sucking fuel from clean carb... I removed bare engine from tiller compleately, and when I spin flywheel by hand with sparkplug in I could hear noise of air leaking (when in compression stage) somwhere inside engine, not to outside. I've removed engine head and inspected gasket... And here is where my inexperience came to light... I've noticed that the whole gasket was nice and shiny , and just in one place gasket was not shiny, and that place was between cylinder and "hole" for valve pushrods... It being the Chinese version of Honda GXV120 meant that I could find replacement gasket. I ordered replacement gaskets, and used water sandpaper on glass surface, and resurfaced head with 400, 800, 1000, 2000 grit papers respectively. When gasket came I used my "calibrated" hand to tighten the head bolts equaly. I tested compression with my finger and it was 10x better. I reasembled, puled 4-5 times and it started. I left it on idle for 15 minutes, all worked fine, waaay better than before, must be that carb cleaning, valve lash adjustment, new cable from coil to bypas switch and new oil made it brand new. I hope that this fix holds and head does not warp again.
Thank you for your suggestions, it brought me to conclusion of what could have been the issue.This is not my profession but i enyojed this process of repair.