Hello everyone! looking for some advice...
My son was riding his 1979 ET340 yeterday when it suddenly quit on him. He left it until I arrived a few minutes later. When I started it, it would barely idle and as soon as a little throttle was given it backfired (seemed to be through the exhaust) and it died.
Here's what we've checked so far:
- Compression is 100 PSI each cylinder. We checked the compression a few weeks ago out of curiosity and noticed it was at 100 PSI. Figured we'd wait and do a piston/ring job in the off season. Maybe this was a bad idea and we should have done it right away. I figured 100 PSI would be enough to continue on the rest of this winter. Unil yesterday the machine ran great and no starting issues.
- Spark plugs appear dark brown, maybe even blackish (not grey).
- Was thinking maybe crank seals, so started again in the garage and while running we sprayed WD40 on the clutch side crank seal (oil pump is removed we're running pre-mix), no apparent change in RPM at idle.
- We noticed the outlet of his muffler (out the bottom) was dented pretty good and was almost closed right up. Was likely from a stump or something he must have hit. We swapped mufflers with another ET340 I own, no change.
Any advice for next steps or possible issues would be greatly appreciated?
Thanks!!
My son was riding his 1979 ET340 yeterday when it suddenly quit on him. He left it until I arrived a few minutes later. When I started it, it would barely idle and as soon as a little throttle was given it backfired (seemed to be through the exhaust) and it died.
Here's what we've checked so far:
- Compression is 100 PSI each cylinder. We checked the compression a few weeks ago out of curiosity and noticed it was at 100 PSI. Figured we'd wait and do a piston/ring job in the off season. Maybe this was a bad idea and we should have done it right away. I figured 100 PSI would be enough to continue on the rest of this winter. Unil yesterday the machine ran great and no starting issues.
- Spark plugs appear dark brown, maybe even blackish (not grey).
- Was thinking maybe crank seals, so started again in the garage and while running we sprayed WD40 on the clutch side crank seal (oil pump is removed we're running pre-mix), no apparent change in RPM at idle.
- We noticed the outlet of his muffler (out the bottom) was dented pretty good and was almost closed right up. Was likely from a stump or something he must have hit. We swapped mufflers with another ET340 I own, no change.
Any advice for next steps or possible issues would be greatly appreciated?
Thanks!!
