| Author |
Message |
    
Tom Kelly
Member
Username: tom_k
Post Number: 7
Registered: 05-2008
| | Posted on Wednesday, June 06, 2012 - 05:55 pm: | 
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Im trying to determan if rebuilbing my Plamer 60 is in order.It runs well but has low performance,wont exceed 1600 rpm,thats about 4knots I recently found a log from the origional owner that docunments a crusing speed of 2200rpms and a max of 2600rpms at 6 knots and 1.5gph.I use twice that. |
J.B. Castagnos
Senior Member
Username: jb_castagnos
Post Number: 692
Registered: 07-2002
| | Posted on Wednesday, June 06, 2012 - 06:46 pm: |
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I would start by looking at the hull-propeller, if the engine is running slow and using more fuel it sounds like it's over loaded. |
Tom Kelly
Member
Username: tom_k
Post Number: 8
Registered: 05-2008
| | Posted on Wednesday, June 06, 2012 - 07:13 pm: |
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The hull or prop havent changed,the hull is cleaned regulary and the prop is in good shape.It seems to have low compression. |
J.B. Castagnos
Senior Member
Username: jb_castagnos
Post Number: 693
Registered: 07-2002
| | Posted on Wednesday, June 06, 2012 - 08:04 pm: |
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If you are not seeing a lot of blow by from the crankcase breather I would start with a valve job. I don't think they would have had hardened valves and seats, unleaded fuel may have worn them out. As the valves recede in to the seats the gap closes holding the valves open. |
Tom Kelly
Member
Username: tom_k
Post Number: 9
Registered: 05-2008
| | Posted on Wednesday, June 06, 2012 - 08:15 pm: |
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There is some blow by,and it increases the longer and harder the engine runs,but its not smoking us out of the boat.My understanding is that the valves arnt in the head so it would involve pulling the engine? |
David C. Dunbar
Member
Username: david_in_ma
Post Number: 20
Registered: 03-2010
| | Posted on Thursday, June 07, 2012 - 04:38 am: |
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The overall ignition system condition, timing may be retarded, the advance may be stuck or not working, the air cleaner may be clogged,carbureter mixture incorrect for some reason, weak valve springs, restrictions in the exhaust system. Investigate all the easy external possibles first. David |
