Bolens QT 16 ignition ????

[docrocky]

This is my third QT 16...The first gave me a challenge in that the engine to PTO drive broke at the universal and it took some time and expense to replace, but i eventually got it done. As i was trying out the rototiller, it lacked spunk and i was only using a surface cultivation for newly sprouted weeds. Engine started and ran smoothly but no real power. I checked spark to both cylinders and it was ok but then on the compression test onc cylinder was zero. Look at prior THREAD and we found totally destroyed push connector rod and piston destroyed. I was so surprised to see one cylinder of a 2 so thoroughly destroyed and yet it ran so smoothly and not noticeably noisy.

Now onto the second QT 16. It starts and runs smoothly but has little if any oomph. Checked spark to each cylinder and both ok. Checked compression to each cylinder and both register 65 psi, and does not change with a little oil lub instilled. I noticed that when testing the spark with tester, the light on one cylinder is not as bright as the other.

A friend has suggested I check the timing but I can not find anything in the manual nor can I find any marks at the front of the engine at the crankshaft pully etc where I can hook up a timing light and advance or decrease the spark. (no distributor cap to rotate ) Or could this be a points and condenser problem? Or does it matter what post from the coil to either spark plug. the coil has 2 terminals for the individual spark plugs. Or can this be a carb adjustment problem and not electrical?

Thanks

 

[seth350]

Poor Bolens

I just finished getting one of these fired up for a friend of mine. I would suggest not touching the timing unless absolutely necessary! The two post coil just fires both cylinders at the same time, so being "out of time" is a possibility but if it is out of time, I doubt it is much.

That Onan is a very forgiving engine, or the one I got going was anyways. Several things got his Onan running in tip top shape.

1) Under the fuel tank is a valve, and it gets trash in it. Also removed fuel pump and cleaned gunk out of it.
2) Removed stock plastic fuel line and fuel filter and replaced with rubber hose and larger fuel filter. (For kicks and giggles)
3) Points were in rough shape, replaced with new set and condenser.
4) Adjusted intake exhaust valves
5) Cleaned carb and adjusted.
6) Intake manifold gaskets were falling apart and was sucking air.
7) Wrapped exhaust pipe with header wrap (For kicks and giggles)
8) One quirky thing with his and others I have read about, is if the fuel tank gets too low, it will run rough. Which just means that the fuel pump isnt performing like it should. But most people just keep it topped off to avoid changing it out.
9) Be sure cooling fins around cylinder heads are clean and free of dirt dobber nests.

That's all I have to say about that....

To atest to how forgiving the Onan was for me....
I got his engine running and mind you it ran but it ran poorly. After all of the above steps I took....the one step that fixed my issue or rather pointed out a different issue was adjusting the valves.
Turns out, both intake valves had a screw lodged in there keeping them from shutting! The way the air cleaner bolts on to the carb is where the screws came from. It is very easy to drop one in and then you have to pull the whole intake and pipes. Not fun!

Getting those screws out and adjusting the valves helped tremendously, naturally!

EDIT:
Forgot one other tid bit for you...
Make sure you have the correct spark plug. The Onan likes a longer necked sparkie than your conventional one in the bottom of your toolbox. :thumbsup: