View Full Version : OMC Tech rebuilt looper problems
We just completed a rebuild of a 93 Evinrude 200 Lim ED. Starboard head doesnt come up to operating temp. Changed thermostats didnt help. Also wont come off high idle unless black and white wire is touched to ground. I suspect the 2 problems are related. Motor was rebuilt all stock with the exception of boring .020 oversize, new wiseco pistons and a polished and balanced crankshaft. I wouldnt think those changes wouls create any sort of problem. Both my OMC tech and myself are at a loss. The thermostat was replaced on that side of the motor. Anyone seen this before? Any ideas? This problem existed prior to the rebuild as well. Thanks for any help (Racer, I sent you a PM regarding this in case you didnt see it_)
perfmarine1
07-02-2016, 12:05 PM
How much of a temp difference? Have you tried swapping the thermostat spring. If one valve(poppet) leaking it will affect temp.
temp on cool side head doesnt change much from ambient temp. oddly enough the block directly behind the head does go up to operating temp
faztbullet
07-02-2016, 11:44 PM
Poppet seal installed correctly???
racer
07-03-2016, 08:47 AM
PM answered. Also correct head gasket orientation. Stock 93 heads? Dividers in block?
yes, I believe head gaskets are oriented correctly but will double check. Heads are stock (I bought the engine new in 1993 and this motor has had never even had the heads removede until the current rebuild, been damn good engine in spite of being driven very hard on a hydrostream).
Not sure what your referring to regarding divider in block?? please advise.
Will check on poppet seal.
Thanks for answering my PM racer. You've bailed this old man out a few times now.
58Evinrude
07-03-2016, 01:17 PM
Is the water restrictor pin in the block on that side?
racer
07-04-2016, 08:52 AM
Block has 3 dividers/pins to route water, two are on the port side and one on the starboard. Parts book shows location. Like mentioned in the PM you need to make sure you do not have water coming thru the hoses from the poppet to the cylinder head at idle, should not have water here until about 15PSI.
Oddly enough i backed the trailer in the neighbors pond,started the engine, it idled at about 1300- RPM for a short time and backed down to about 650 RPM. Perfect. I believe I had a bad thermostat. Having exhaust back pressure was what it needed.Both heads equally hot so I believe as soon as its broke in its ready to roll.
As i mentioned at the beginning of this thread its all stock OEM parts with the exception of the wiseco pistons, .020 overbore and a polished crank its bone stock. I have a set of Chris carson reeds coming. The 1993 LE came stock with the 225 HP pistons. Porting was not done during rebuild for reliability reasons.
My question is other than installing the reeds what else, if anything can be done to get a bit more HP out of it short of porting?
Thanks for all of the help. A special thanks to Racer. You are the Guru for OMC guys. I sure miss the days of mod VP watching you race in Bay City,Mi. The only OMC in the race and the 2.4's couldnt come close on the straightaways. Amazing watching you spin in turn one, finally getting restarted after being lapped coming back and either winning or coming cose to winning. Obviously I'll not forget that race. Hell, I dont remember what I did this morning but I sure remember that.
Block has 3 dividers/pins to route water, two are on the port side and one on the starboard. Parts book shows location. Like mentioned in the PM you need to make sure you do not have water coming thru the hoses from the poppet to the cylinder head at idle, should not have water here until about 15PSI.
I didnt know that. Thanks for the info.
warriorcookie
07-04-2016, 05:48 PM
-Get your setup right. Engine height, setback, prop, etc. This is usually cheapest and worth the most.
-Plug the idle reliefs.
-2.7 heads (hard to find) or some perf heads from Al Stoker, Bush, etc.
-225hp carbs/throttle bodies.
Those are the easy ones. Make sure once you start monkeying with this motor you jet the carbs properly. This also includes jetting #2 one size richer. Don't forget these carbs crossflow.
racer
07-05-2016, 07:35 AM
93 limited edition has 225 carbs.
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