| Author |
Message |
    
Michael Michler
New member
Username: b52
Post Number: 1
Registered: 07-2009
| | Posted on Thursday, July 02, 2009 - 01:43 pm: | 
|
This is a 1980 80 hp. All timing points are set correctly. 15P prop which is minimum needed operating at 5000 ft. altitude. New carb rebuild. Starts, idles and runs great up to 2800rpm. When asked to go more it bogs out. This is the point where the butterfly valves start to open. When the choke(enrichment valve) is opened at the 3000rpm point the motor wants to take off. Will make 5500 rpm. Back off the throttle and it will bog out again. Main jet at .090 have tried recommended .086. Have not changed vent jets. New fuel pump kit and fuel seems to be pumping well. What am I missing ?? |
JB
Senior Member
Username: beckerjs
Post Number: 1755
Registered: 11-2005
| | Posted on Thursday, July 02, 2009 - 02:42 pm: |
|
did you try opening idle mixture screw 1/8 to 1/4 richer, helps it through the lean spot/won't idle quite as smooth |
Michael Michler
New member
Username: b52
Post Number: 2
Registered: 07-2009
| | Posted on Thursday, July 02, 2009 - 03:28 pm: |
|
Tried that. I am now looking at fuel starvation. I may have a bad disconnect fitting on the engine side. Thanks |
JB
Senior Member
Username: beckerjs
Post Number: 1756
Registered: 11-2005
| | Posted on Thursday, July 02, 2009 - 03:53 pm: |
|
you could simply pump the bulb by hand to see if that improves anything. It sounds as if you have a good working knowledge, good luck. |
Fastjeff
Senior Member
Username: fastjeff
Post Number: 6186
Registered: 09-2003
| | Posted on Thursday, July 02, 2009 - 04:32 pm: |
|
Try delaying the point where the butterflies start to open even further. That's mighty thin air up there, pardner!
Jeff |
Tony Delio
Senior Member
Username: tonyob
Post Number: 1482
Registered: 05-2001
| | Posted on Thursday, July 02, 2009 - 05:54 pm: |
|
The throttle plates should open a long time before the engine reaches 2800 rpms. |
