Onan P218

Troubleshooting, rebuilding, repairing Onan engines.
TLD89 United States of America
Posts: 67
Joined: Thu Dec 16, 2021 2:36 pm
Location: Collinsville, Il,
Has thanked: 209 times
Been thanked: 278 times

Onan P218

Post by TLD89 »

I decarb and set values, now motor turns over with spark and fuel and backfires. But does not run. Not sure that I turned the motor clockwise when setting values. Could that be the problem?
When setting values I set them at BTC should I've set them at 20 degrees?
User avatar
Eugen Canada
Posts: 5141
Joined: Wed Mar 03, 2021 2:52 pm
Location: Port Mcnicoll, Ontario
Has thanked: 11934 times
Been thanked: 16194 times
Contact:

Re: Onan P218

Post by Eugen »

TLD89 wrote: Wed Mar 01, 2023 10:23 am I decarb and set values, now motor turns over with spark and fuel and backfires. But does not run. Not sure that I turned the motor clockwise when setting values. Could that be the problem?
Might help to give a little more context about this engine. Was there a problem at all before, did it work at all?

If you set the valve clearance properly I don't think it matters which way you turn the engine to get to TDC. For backfires timing is a usual culprit. But the fact that you touched the valves, that may be involved in it too.
Case 224, 444, 644, 680E
Kubota B26 :blush:
User avatar
DavidBarkey Canada
Posts: 3107
Joined: Sat Mar 06, 2021 10:35 am
Location: Waverley On.
Has thanked: 17068 times
Been thanked: 10411 times

Re: Onan P218

Post by DavidBarkey »

TLD89 wrote: Wed Mar 01, 2023 10:23 am I decarb and set values, now motor turns over with spark and fuel and backfires. But does not run. Not sure that I turned the motor clockwise when setting values. Could that be the problem?
When setting values I set them at BTC should I've set them at 20 degrees?
Yes , What Eugen said . Need more background.
How did it run before ? Why did you adjust the valves , were they out of spec ? What all did you do to the engine ? Does it back fire out the exh. or the carb ?
Dave
Mad Tractor Builder
TLD89 United States of America
Posts: 67
Joined: Thu Dec 16, 2021 2:36 pm
Location: Collinsville, Il,
Has thanked: 209 times
Been thanked: 278 times

Re: Onan P218

Post by TLD89 »

Eugen wrote: Wed Mar 01, 2023 10:37 am
TLD89 wrote: Wed Mar 01, 2023 10:23 am I decarb and set values, now motor turns over with spark and fuel and backfires. But does not run. Not sure that I turned the motor clockwise when setting values. Could that be the problem?
Might help to give a little more context about this engine. Was there a problem at all before, did it work at all?

If you set the valve clearance properly I don't think it matters which way you turn the engine to get to TDC. For backfires timing is a usual culprit. But the fact that you touched the valves, that may be involved in it too.
The motor ran before with the choke partly closed. I think it had a carb issue, so I cleaned the carb and sealed the intake manifold seam.
TLD89 United States of America
Posts: 67
Joined: Thu Dec 16, 2021 2:36 pm
Location: Collinsville, Il,
Has thanked: 209 times
Been thanked: 278 times

Re: Onan P218

Post by TLD89 »

TLD89 wrote: Wed Mar 01, 2023 4:05 pm
Eugen wrote: Wed Mar 01, 2023 10:37 am
TLD89 wrote: Wed Mar 01, 2023 10:23 am I decarb and set values, now motor turns over with spark and fuel and backfires. But does not run. Not sure that I turned the motor clockwise when setting values. Could that be the problem?
Might help to give a little more context about this engine. Was there a problem at all before, did it work at all?

If you set the valve clearance properly I don't think it matters which way you turn the engine to get to TDC. For backfires timing is a usual culprit. But the fact that you touched the valves, that may be involved in it too.
The motor ran before with the choke partly closed. I think it had a carb issue, so I cleaned the carb and sealed the intake manifold seam.
The values did have carbon build up and where a few thousands off. I did take the timing gear cover off carefully cleaned the stator.
User avatar
DavidBarkey Canada
Posts: 3107
Joined: Sat Mar 06, 2021 10:35 am
Location: Waverley On.
Has thanked: 17068 times
Been thanked: 10411 times

Re: Onan P218

Post by DavidBarkey »

TLD89 wrote: Wed Mar 01, 2023 4:05 pm
Eugen wrote: Wed Mar 01, 2023 10:37 am
TLD89 wrote: Wed Mar 01, 2023 10:23 am I decarb and set values, now motor turns over with spark and fuel and backfires. But does not run. Not sure that I turned the motor clockwise when setting values. Could that be the problem?
Might help to give a little more context about this engine. Was there a problem at all before, did it work at all?

If you set the valve clearance properly I don't think it matters which way you turn the engine to get to TDC. For backfires timing is a usual culprit. But the fact that you touched the valves, that may be involved in it too.
The motor ran before with the choke partly closed. I think it had a carb issue, so I cleaned the carb and sealed the intake manifold seam.
Lean can also cause back fires up the carb . Check your fuel supply to the carb for restrictions. Do a compresstion test to rule out valves issues as well .
Dave
Mad Tractor Builder
TLD89 United States of America
Posts: 67
Joined: Thu Dec 16, 2021 2:36 pm
Location: Collinsville, Il,
Has thanked: 209 times
Been thanked: 278 times

Re: Onan P218

Post by TLD89 »

TLD89 wrote: Wed Mar 01, 2023 10:23 am I decarb and set values, now motor turns over with spark and fuel and backfires. But does not run. Not sure that I turned the motor clockwise when setting values. Could that be the problem?
When setting values I set them at BTC should I've set them at 20 degrees?

Still have the issue with starting. I checked timing with timing light and the timing mark TDC on flywheel is not even close to the TDC on the timing gear cover, it is at about 8 o'clock. The flywheel is in the correct position with the keyway on the shaft.
When decarbing nothing was touched with the cam or crank gears, only took timing gear cover off to retrieve value keeper. The governor linkage is also installed correctly.
Changed ignition module with a used one I had still have the same problem. Any ideas ?
User avatar
Spike188 Canada
Posts: 1057
Joined: Sat Mar 06, 2021 12:58 pm
Location: Ayr Ontario
Has thanked: 5595 times
Been thanked: 4040 times

Re: Onan P218

Post by Spike188 »

You have me stumped on the timing issue. If the timing cover was off, conferming that the cam and crankshaft gear timing marks line up would be a first check. The ignion module position is another thought. Dave may have some ideas.
Spike Colt - 9 & 10, Case - 108, 118, 444, 446, 448, 646, 646bh, Ingersoll 4016, 4118AH
Jancoe United States of America
Posts: 323
Joined: Sat Mar 06, 2021 3:09 pm
Location: Houghton Lake, MI
Has thanked: 16 times
Been thanked: 1428 times

Re: Onan P218

Post by Jancoe »

How about checking float height on your carb? Are you pushing to much gas through the carb?

Sent from my SM-S906U using Tapatalk

User avatar
DavidBarkey Canada
Posts: 3107
Joined: Sat Mar 06, 2021 10:35 am
Location: Waverley On.
Has thanked: 17068 times
Been thanked: 10411 times

Re: Onan P218

Post by DavidBarkey »

For it to be that far out . The trigger ring has to be on backwards or not on the key properly some how .
Dave
Mad Tractor Builder
Post Reply