Small engine repair anyone????

[vrodjason]

Ok here's where we are at today. Did the compression test. Rear cyl was 115 front cyl 110. Soooo... I'm thinking mayne the condenser. Called around and no one seems to have one or even wants to help me find one. Go figure- no one must want my business! Economy must not be too bad. WHat do ya'll think now????

[madjack]

Jason, make absolutely sure you have spark...put original coils back on, remove spark plug wire and using insulated pliers hold near spark plug while cranking the motor and see if it throws a good spark(check to see if they make a solid state module to replace points and condenser)...if you have spark, then your fuel system becomes suspect...blown intake gaskets(sucking air), blocked fuel filter, or blocked jets/needle valve in carb...remove both spark plugs and squirt a small amount of fuel directly in cylinder, replace spark plugs and try to start.........
madjack

[Kevin A]

Ok here's where we are at today. Did the compression test. Rear cyl was 115 front cyl 110. Soooo... I'm thinking mayne the condenser. Called around and no one seems to have one or even wants to help me find one. Go figure- no one must want my business! Economy must not be too bad. WHat do ya'll think now????

This is a good sign, now we know it's likely not an internal engine problem. If you can't find a condenser locally try these guys
http://www.jackssmallengines.com/index.html (no affiliation with our illustrious admin of the same name )
You'll likely still get a spark with a bad condenser but the points will arc and burn. For peace of mind it's best to replace it when you replace points.
Once you establish a good blue spark at the plug, see if it will run. If not, it's time to move on to the carburetor. If you wind up ordering a condenser from the link above, you might want to get a carburetor kit and possibly an intake manifold gasket as well. Rebuild the carb and clean out the fuel tank, lines and replace any fuel filter it might have in the system. Keep us posted.

[IASCOTT]

I would make sure the plug wire isn't shorting out to ground. If possible switch the two plug wires around and see if your dead cylinder moves. If it does then its the plug wire. You can do the same thing with the spark plug but i see you have replaced them so most likely that's not the trouble. I would also make sure the that your valve train is actually functioning correctly. Even if the valve aren't opening you will still get a compression reading.

Scott

[vrodjason]

iascott, i have already tried switching the plug wires and the prob didn't travel with the wire. I even put different wires (used) on and still the same prob. After I thought for a while I remember an old guy who messes around with old mowers. He used to own a mower shop but now just tinkers on them but he can still order parts. I went to talk to him and told him what I have and the problem and he just grinned. He pulled out his parts book and showed me that his suppliers don't even carry condensers for an Onan anymore. So I asked what is the difference between one from the other. He said nothing except how they are mounted. He then told me a way to check a condenser. This is where you guys come in and tell me if this is possible. He said to disconnect the condenser wire, remove a plug wire, put the condenser in the plug boot making sure there is good metal on metal contact and turn the engine over. He said this "charges" the condenser. Then take the condenser wire and ground it to the condenser case. He said it should spark if it is good. I tried it without knowing if it was a good test or not and I got no spark. So I think my next step will be to see how good of a spark I am getting at the plugs. I'm still not sure if this is the full problem b/c if it was the condenser wouldn't it affect both cylinders?

[madjack]

...to test a condenser with an ohm(volt) meter...first touch the lead to the case, ensuring full discharge...next, with the meter set to Ohms, touch leads to the body and lead of condenser...it should show almost no ohms at first but steadily increase to infinite ohms(almost immediately) as the condenser charges...if it shows infinite ohms from the beginning, it is bad...the make/model/brand of condenser shouldn't mater as long as it physically fits in the mounting spot provided.........
madjack

[vrodjason]

Thanks madjack!! He said as long as I could find a place to put it and make sure it is grounded any condenser will work.
Has anyone heard of the "charging" the condenser test?

[vrodjason]

No progress today. Did't get to work on it at all. Went to look for my volt ohm meter and realized it is at my work so i'll bring it home tomorrrow and do the comdenser test. Let know something then!

[IASCOTT]

Ok now I we need to know if you just switched the wires at the spark plug or did you also switch them at the coil also. If switching the plug wires at just the coil doesn't change what cylinder is running then its not an ignition trouble but something with that cylinder. If it does then one side of the coil is bad. Onan fire every time a piston come up on TDC either if its on the exhaust stroke or the compression stroke.

A person also needs to make sure the timing is correct. But sense you have one cylinder working I don't think this is the problem either.

Now I'm going to assume its a single carb engine and sense we have one cylinder working we can eliminate that as a problem. But I would make sure there isn't a huge vacuum leak. Or something got past the carb and plugged the intake side of the dead cylinder. Which I don't think you have because you are able to get one cylinder to fire. But I would still make sure some critter didn't decide to take up residence in your intake system.

Now if neither of these are true then most likely the intake valve isn't opening for some reason. If the valves aren't opening you can still get a good compression reading on a compression test.

Now I would be real careful when playing around with condensers they can pack quite a charge and aren't anything you want to be zapped with.
But I don't think its the condenser sense you have on cylinder working. I think you have an internal problem with you valve train.

Scott

[madjack]

Jason, the test I described is a "charging" test...you are simply using the battery in the meter to charge the condenser...you can also accomplish the same thing by attaching the condenser across a 12v(or other) battery...beware that any charge you put into the condenser will come right back out under discharge.........
madjack

[vrodjason]

madjack, dumb me realized it was charging it after after I responded to your reply. I read your post again and the light bulb went off!

iascott, I took the dual output coil off and installed two single output coils on. So I think I have ruled out the coil/s. I also had thought about a gasket leaking big time creating the prob. I seem to remember the guy I got it from saying these motors were bad for intake leaks. Wish I had checked this first.

So here is my new plan of attack- 1) Check intake for obstructions 2) Check all of the gaskets 3) Check the condenser.

I'm thinking if none of these seem to be the prob. I'm going to take it out to my dad's and put it in his barn. He's always looking for a side project. Since he retired he gets bored plus I think he has ADD. He works on 20 things at a time somehow and usually all in the same day!

[vrodjason]

Went home yesterday and started working on the tractor. Did a visual check on the intake gaskets. No obvious blowouts. Checked inside the air cleaner for signs of critters. None. On my way home stopped and got a condenser. The parts store guy looked at me a little funny when I told him I didn't care what it was for as long as it had a mounting tab. But anyway, checked the condenser per madjack's instructions. Bad! So put on the $2.91 condenser, adjusted the points and primed the carb. Hit the key switch and "holy cow it's running"!!!!! Now all I need to do is adjust the carb a little and she should be good to go.

Thanks for everyone's help! Without your help, this would have been a miserable experience. Again thanks to all!

I'm going to put a few pics in my album if you would like to see it.

[Cutterpup]

So it's safe to say that you condense this to it's lowest level?

Dan

[madjack]

Jason glad to know we/I could be of help.................................

p.s. unfortunately, you no longer have an excuse to NOT mow the grass ..................MJ

[Kevin A]

Went home yesterday and started working on the tractor. Did a visual check on the intake gaskets. No obvious blowouts. Checked inside the air cleaner for signs of critters. None. On my way home stopped and got a condenser. The parts store guy looked at me a little funny when I told him I didn't care what it was for as long as it had a mounting tab. But anyway, checked the condenser per madjack's instructions. Bad! So put on the $2.91 condenser, adjusted the points and primed the carb. Hit the key switch and "holy cow it's running"!!!!! Now all I need to do is adjust the carb a little and she should be good to go.

Thanks for everyone's help! Without your help, this would have been a miserable experience. Again thanks to all!

I'm going to put a few pics in my album if you would like to see it.

Jason,

That's great news.
I'm glad we were able to help lead you in the right direction and that you avoided tearing the engine down looking for valve train problems that were not there.