[schossow5]

Hi,
I've inherited my Opa's Ingersoll(Case) 448. It's an 88 with the Onan 18hp of course. It's been sitting for roughly 10 years.
What I've done so far having read many many posts :
Changed all fluids
Removed cylinder heads and cleaned off all carbon deposits including valves
Replaced Battery
Replaced plugs
Cleaned Carb
removed shrouds and cleaned out all dirt and debris(mouse nests)
New intake and head gaskets

After doing all the above I started her up. vvvrrooom. I was pleasantly surprised, considering it hadn't been started for 10 years or more.
However, my delight was short lived as I could hear an obvious misfire.
I felt each cylinder head and the left was room temp and the right(obviously) was hot. So I checked for spark in the left and there was none. From what I've read I should do some electrical diagnostics on the coil and the points system. I'm not very electrically savvy so I was wondering if maybe there was a quick answer someone may know of, given the symptom(one having spark, the other not), that may help me bypass doing all the electrical diagnostics.

 

[RestMyCase]

Since both cylinders fire at the same time and you have spark on the righside, I would rule out the points/condenser. Do a coil test as outlined in the Onan B-series service manual.

:trink40:

 

[rscurtis]

Switch the plug wires between cylinders and see if the problem follows the wire. If it does, you have an ignition problem. If it doesn't, there is another problem, possibly a vacuum leak.

 

[schossow5]

Well, I was out at the shop after RestMyCases' reply. I bought a multimeter and downloaded the B48M service manual. I checked the coils resistance per the manual and everything was within parameters. What I did notice is that the boot for the malfunctioning plug may not be fully seating in the terminal. It is very different from the other plugs wire, almost like the piece that makes good contact is broken off. I'm going to try switching the plug wires and see what happens. Wont get to the shop until tomorrow.

 

[burned300]

You can also switch plugs, ( I know, they are new) I had a Champion die more that once

 

[schossow5]

Update:
S crazy as it sounds after testing everything that carys a current I did end up switching plugs and found spark. What a headache. Popped in a new plug and everyone was great....for 5 seconds. It didn't take long to hear the misfire, again left cylinder. So I read a bunch of posts and went through and gaped the points ( they were wayyy off) and adjusted the valve clearance, also off but only the intake valves in both cylinders. Put it all back together fired her up and no change. For kicks I decided to check for a leak with starter fluid and found the leak in the left cylinder intake gasket. Was brand new, but I must have broke it setting it in( scraped against a fin or bolt, dunno). So I made one out of cardboard, until the next arrives, and she runs beautifully.

Thank you for all the advice. This is an amazing machine and running in tip top shape.




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