6HP Evinrude / no power

J

jddsmt

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Feb 22, 2004
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I have a 6hp Evinrude ser# 6202D J08497, I believe it is a 1972 model. I have replaced the coils, plug wire, condensers, points and re built the carburetor with a kit. The engine starts up great and has plenty of RPM when not in gear, however when I put it under load it drops RPM's and does not provide much power. It will however jump in RPM,s if I raise the engine out of the water and allow the prop to catch air but when it goes back in the water RPM's drop. I also done a compression test on both cylinders and got 75 top, and 80 bottom.<br /> Can someone please give me a direction to run with I'm all ot of suggestions. :confused:
 
D

DJ

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Re: 6HP Evinrude / no power

James Taylor,<br /><br />Most likely you are only running on one cylinder. They will surprise you at how well they will run on one, with no load.<br /><br />Your compression is good, so something else is amiss. Check for spark on both cylinders. You can pick up a cheap spark tester at any auto parts store.
 
J

jddsmt

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Re: 6HP Evinrude / no power

DJ:<br /> Thanks, will give it a try and see where it takes me.<br /> James
 
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Paul Moir

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Re: 6HP Evinrude / no power

I noticed you mentioned that you replaced your plug wires. You didn't happen to have used automotive type carbon core ones did you? Some have reported similair symptoms when they used suppressor wires with your magneto ignition system. IE, it worked fine until they put the engine under load.<br />Another idea is to carefully check your coil placement. Having the airgap between the magnet and flywheel just right makes a big difference on your spark intensity. I find they're worth fiddling with when you don't have the coil alignment ring.<br /><br />Finally, the armature plate is moving freely, right?
 
J

jddsmt

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Re: 6HP Evinrude / no power

Paul:<br /> I replaced the plug wires with the 7mm copper core, and the armature is moving freely. I will look at the gap on the coils, not much room to play with due to the fly wheel catching the corner of the coil's. What gap do you recommend.<br /> Thanks James
 
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Paul Moir

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Re: 6HP Evinrude / no power

Just line them up with the bosses as best you can. If your already getting good hot sparks that can jump up to a 3/8ths gap I wouldn't worry about them.<br /><br />OK, try disconnecting a cylinder and grounding the spark lead. Then start and run the engine. See if the drop out sounds any different. Then try the other cylinder. <br /><br />If it seems to run on one just the same as the other, suspect a fuel problem. Try putting a little fuel/oil mix in a spray bottle (one that really atomizes) and try spraying a bit down the carburator's throat while you run it. <br /><br />PS - Don't rev your engine in neutral or operate it above 1500rpms without a load. They have a tendency to run away.
 
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Xcusme

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Re: 6HP Evinrude / no power

James Taylor,<br />You can find a picture of the coil placement in this thread... ;) <br /> Coil Pic
 
R

R.Johnson

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Re: 6HP Evinrude / no power

Check the exhaust by-pass cover for leak's. you could be pulling water into the bottom cylinder. This is why the engine rev's out of the water.
 
Chinewalker

Chinewalker

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Re: 6HP Evinrude / no power

It's also possible you've got a blown head gasket. Easy enough to check...<br />- Scott
 
J

jddsmt

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Re: 6HP Evinrude / no power

DJ, Paul, Xcusme, R. Johnson and CHINE WALKER;<br /> Thank you all for your response.<br />I took each of your trouble shooting procedures and ran them to the ground. I found that while trying to save a dollar and make your own gaskets is not worth it, the head gasket that I made had burnt through, causing compression loss. She is running now on both cylinders and sounds as though she can push my john bout through the water.<br /> Once again thanks! <br /> James
 
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