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1071 evinrude 9.5 hp No top end power! pLease help!

kawi027

New member
Okay im a bit frustrated with my 1971 evinrude 9.5 hp model 9122 R. Heres whats goin on.

Engine runs great in the garage idle and runs smooth...purrs like a kitten.
I take it out to the lake in my 12 ft aluminum flat bottom with just me in the boat and 6 gallons fuel etc, I weigh about 200lbs and the thing goes about 8mph and I can barely get the front end to plane! I have done all the repairs listed below (except the points adjustment) and have already been on the water and they have made no difference whatsoever. Heres what Ive done:

Took the top of the carb off (looked pretty clean) except I noticed a tiny bit of debri in the float bowl (probably from the old float) , so I sprayed out every orifice, removed the high speed jet and sprayed with carb cleaner and blew it and the rest of the carb with air. Also I visual checked out all the fuel lines and did not notice any leaks.

Compression is about 80lbs in both cylinders using the pull rope, check to see if both cylinders were working by removing 1 spark plug at a time (both are running ).

Prop seems fine, this is a short shaft evinrude, I tried different prop angles in the water and nothing helped, even messed with the lean/rich dial...nothing!

I have not checked the reeds yet but I did not see the carb spitting any fuel up and plus the thing sounds great just no power on the top end. When I have it full throttle it sounds like the engine has a lot more RPM to go (and yes I checked the throttle linkage and it is getting full throttle.

I bought this engine a few weeks ago and the old owner said that it had been sitting for about a year because the last time he took it out it overheated on him and was smoking (due to a bad water pump). I took apart the water pump and the set pin had stripped out the old water pump key so I replaced the complete water pump and it no longer overheats.

The only thing I adjusted but have not taken to the lake since I adjusted it were the points, both were set at about .013 so I readjusted them to the correct .020. Also the rest of the ignition system looks pretty new. Since the points were off by this amount would that affect the top end power?, I started it up and the engine sounds about the same when the points were off.

Sorry for the long essay but I wanted to give all u guys as much info as possible. Im heading to Big Bear tomorrow (friday) and would appreciate any quick tips on things I may have missed and could check.

Thanks in advance.
 
Is it running on two cylinders??? After you run it, shut it down and feel the cylinder heads to see if they are the same temperature...if they are not...it is running on a single cylinder. You could also confirm this by dis-connecting one plug wire at a time to see if they are both contributing.
 
oops...I missed your confirmation that it is running on both cylinders. These motors often leak exhaust under the cover and lose power for that reason...try running with the cover off to see if it makes a difference.
 
Fill a oil squirt can with fuel/oil mix and squirt it into the carb at full throttle to see if the problem is fuel starvation. What is the spark plug color after the motor has been running? Overheating often causes head gasket failure but your compression numbers don't seem to indicate that.
 
You need to check the ignition system -----will spark jump a gap of 1/4" or more ???---------------------Have you checked the lower unit for binding ???
 
Your points being off that far will effect the performance! Now that they are set to.20 have you run it?
 
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