Can not figure out what is wrong with 1983 enticer.

[RMK-King]

I have a yamaha 83 enticer 300 that has a issue I can not figure out for the life of me. It misses on the mag side cylinder, it does it the worst under half throttle. When idling the temp of the pto cylinder will be 300F and the mag side will be 110F. The mag spark plug is usually wet.

What I have done/checked.
- cleaned carb and verified flow from the fuel pump
-New CDI
- New spark plug wire caps, swapped wires and ran it to verify it is not a cdi/coil issue.
- Compression check showed 98psi on both cylinders
-sprayed carb cleaner around pto crank seal and all around intake to check for air leaks.


I am out of ideas as to why that one cylinder misses when they both share the same carb and both have the same compression with good spark. Any ideas are appreciated!!

 

[sifton]

I have a yamaha 83 enticer 300 that has a issue I can not figure out for the life of me. It misses on the mag side cylinder, it does it the worst under half throttle. When idling the temp of the pto cylinder will be 300F and the mag side will be 110F. The mag spark plug is usually wet.

What I have done/checked.
- cleaned carb and verified flow from the fuel pump
-New CDI
- New spark plug wire caps, swapped wires and ran it to verify it is not a cdi/coil issue.
- Compression check showed 98psi on both cylinders
-sprayed carb cleaner around pto crank seal and all around intake to check for air leaks.


I am out of ideas as to why that one cylinder misses when they both share the same carb and both have the same compression with good spark. Any ideas are appreciated!!

Plugs? What ones are you using?

 

[Aerosled]

Here's something to check. Is the carb mounted perpendicular to the engine? This link is about Rotax twins with a single carb. I'm not sure about the Yamahas.
http://www.eaavideo.org/video.aspx?v=2043795780001

 

[08nytromtxa]

i would point toward coil. if your plug is wet must have weak spark.

 

[Fiddy]

300 enticer

if the fuel pump pulse line comes from that side it may be leaking trhough the diapfram in the pump letting excess fuel into case, pinch it off and try ita little, happened to me filling the case. will need pump rebuilt.

 

[RMK-King]

if the fuel pump pulse line comes from that side it may be leaking trhough the diapfram in the pump letting excess fuel into case, pinch it off and try ita little, happened to me filling the case. will need pump rebuilt.

Checked the pulse line and it is dry.

i would point toward coil. if your plug is wet must have weak spark.

Swapped the plug wires around and it was still the mag cylinder, it should have switched to the other cylinder if that was the issue.

 

[protech offroad]

I would check the crank seal behind the mag.

 

[RMK-King]

I would check the crank seal behind the mag.

I think that is the next step,only other thing I can think of.

 

[bobby56477]

choke setting

i have a 86 yamaha phazer i''ve tryed to set choke to spec but they don''t seen to work what i''m i doing worry

 

[yumyum300]

Did you ever find the problem with your Enticer? I bought a 83 Yamaha 300 Enticer that has the same problem.

 

[stingray719]

I would check the crank seal behind the mag.

Would be my best guess. In the old days we would undo the pulse line and have a smoker blow smoke in the line with the piston on the down stroke and watch for smoke.

 

[m8magicandmystery]

I have a yamaha 83 enticer 300 that has a issue I can not figure out for the life of me. It misses on the mag side cylinder, it does it the worst under half throttle. When idling the temp of the pto cylinder will be 300F and the mag side will be 110F. The mag spark plug is usually wet.

What I have done/checked.
- cleaned carb and verified flow from the fuel pump
-New CDI
- New spark plug wire caps, swapped wires and ran it to verify it is not a cdi/coil issue.
- Compression check showed 98psi on both cylinders
-sprayed carb cleaner around pto crank seal and all around intake to check for air leaks.


I am out of ideas as to why that one cylinder misses when they both share the same carb and both have the same compression with good spark. Any ideas are appreciated!!

where does it say you changed the plug..??...did you

 

[sifton]

Pull your airbox off and seperate the two half's. You may have something inside restricting your air flow. Happened to me on a 340 Enticer once.