bob johnson
Rear Admiral
- Joined
- Feb 25, 2009
- Messages
- 4,306
been dealing with a warm port head for a while, asking a lot of questions, trying every remedy I can find..
bought some extra heads to try out....cleaned them up and got them ready, then went and took the old ones off.
I am posting a picture of the plugs, wondering about a possible lean condition..dont know how to diagnose that...trying to find out why the head runs hot..
the dont look too bad to me. I discover the bottom port cylinder is .030" over size....wonder if the carb jets were not changed if this could lead to a lean condition...
the combustion chambers are all pitted....but they are also pitted on the head i took off the 90 hp spare motor I have.
the 115 hp heads i bought off craigslist are beautiful with no pitting.
this is the head i just took off my motor
the bottom head here is from the 90 hp spare motor I have, and the top one is the used 115 head i bought and surface cut...
this a picture of the pistons in the block, slight carbon and some clean wash near the ports..
what is the pitting from...saltwater maybe?? carbon particles exploding in the chamber?
nothing is obvious on the take off heads as to why they port over heats
what about any other way to diagnose a lean condition, or any other cause for over heating( 190-200 degrees sometimes around 3000-3800 rpms...lower or higher the temperature falls to 170 ish...but the other head is always 30-50 degree cooler....
thanks
bob
bought some extra heads to try out....cleaned them up and got them ready, then went and took the old ones off.
I am posting a picture of the plugs, wondering about a possible lean condition..dont know how to diagnose that...trying to find out why the head runs hot..
the dont look too bad to me. I discover the bottom port cylinder is .030" over size....wonder if the carb jets were not changed if this could lead to a lean condition...
the combustion chambers are all pitted....but they are also pitted on the head i took off the 90 hp spare motor I have.
the 115 hp heads i bought off craigslist are beautiful with no pitting.
this is the head i just took off my motor
the bottom head here is from the 90 hp spare motor I have, and the top one is the used 115 head i bought and surface cut...
this a picture of the pistons in the block, slight carbon and some clean wash near the ports..
what is the pitting from...saltwater maybe?? carbon particles exploding in the chamber?
nothing is obvious on the take off heads as to why they port over heats
what about any other way to diagnose a lean condition, or any other cause for over heating( 190-200 degrees sometimes around 3000-3800 rpms...lower or higher the temperature falls to 170 ish...but the other head is always 30-50 degree cooler....
thanks
bob