jmendoza
Petty Officer 1st Class
- Joined
- Jun 9, 2008
- Messages
- 314
I finally rebuilt my 1975 Johnson 9.9 w/ 15 conversion last fall. Every year since 1982 I have been promising myself I would tear down the power head and overhaul it during the winter, every year I would close up the cabins and not think about it until they were under 4 feet of snow, oh well! Not wanting to spend the limited time I do have at the lake wrenching, instead, the little Johnny has endured for years with little or no service other than an occasional plug change. 25 years ago I purchased .030" over pistons, rods, bearings, engine and lower unit seals, pump kit, and complete gasket set in anticipation of doing a total overhaul, as the engine had been seized once due to overheating. Then a couple years ago, a decent powerhead became availlable for only $100.00 on ebay, it was pristine, albeit an Evinrude, it was a 1975 and identical. That kicked around my garage for a year until I got tired of it and decided to slap it on the Johnny, and rebuild the original power head some time later, if at all. Boy, am I glad I did this job!!
I found some severe problems:
1. Corroded hole in block where upper water tube grommet seals allowing a big cooling leak.
2. Torn fuel pump diaphragm, caused engine to sometimes cut out at low speed.
3. Lower unit full of chocolate milk, bad drive and prop shaft seals.
4. Timing was off and out of sync with carb.
5. Rock hard fuel lines were leaking at fittings, needed replacing.
End result is an engine that starts on the first pull. Thanks To John Gill of Holloways Marine in Big Bear Lake for lending me some special tools for the ignition and lower unit/gear case. John also got me the original gold paint(actually an olive drab metal flake) from BRP, and Thanks to Nanas decals, they are perfect matches for the old faded ones on the cowl.
Although the old engine still had great compression, it lacked crankcase compression, as such the new engine does not seem to be any faster, but sure gets there quicker, meaning it pulls and accellerates much quicker. Oh, and it uses about half the fuel it once did as well. Best of all, it looks like new.
I found some severe problems:
1. Corroded hole in block where upper water tube grommet seals allowing a big cooling leak.
2. Torn fuel pump diaphragm, caused engine to sometimes cut out at low speed.
3. Lower unit full of chocolate milk, bad drive and prop shaft seals.
4. Timing was off and out of sync with carb.
5. Rock hard fuel lines were leaking at fittings, needed replacing.
End result is an engine that starts on the first pull. Thanks To John Gill of Holloways Marine in Big Bear Lake for lending me some special tools for the ignition and lower unit/gear case. John also got me the original gold paint(actually an olive drab metal flake) from BRP, and Thanks to Nanas decals, they are perfect matches for the old faded ones on the cowl.
Although the old engine still had great compression, it lacked crankcase compression, as such the new engine does not seem to be any faster, but sure gets there quicker, meaning it pulls and accellerates much quicker. Oh, and it uses about half the fuel it once did as well. Best of all, it looks like new.
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