Here is a picture of the spark plugs in my 9.8. The left one is the top. Can someone tell me what might cause them to run different? Possible solutions on what to look for. Thanks for any help.
The motor runs OK at best. Not great. The only thing I have done to check the spark is take the plug wires off one at a tme. The motor did die when doing this but it took a little longer when the bottom one was pulled. Do you think it would be worth getting under the fly wheel to check things out or should I be looking some where else. I did buy a spark checker which is basically a tool that goes between the plug and the wire. Is this a sufficient spark check? The compression is 100 on both cylinders.
My 3 cylinder 90HP 2 stroke plugs look a bit different, the middle cylinder plug where the prime start enrichening device is located seems darker than the top and bottom plugs. Maybe it's caused by that rich mixture during start up, but can't say for sure? That Harbor Freight Spark Plug sandblaster works great if you have a compressor. Good Luck!
The motor runs OK at best. Not great. The only thing I have done to check the spark is take the plug wires off one at a tme. The motor did die when doing this but it took a little longer when the bottom one was pulled. Do you think it would be worth getting under the fly wheel to check things out or should I be looking some where else. I did buy a spark checker which is basically a tool that goes between the plug and the wire. Is this a sufficient spark check? The compression is 100 on both cylinders.
I don't know how old your plugs are, but the white insulator on the left and what I can see of a white insulator on the right tell me that your plugs are running too cold. If you go to the Champion www you can see the proper color for plugs. Obviously a 2 cycle OB plug will be oily but the colors/damage will be the same.
Possibly if you get the correct temp plug the fowling will cease as the oil accompanying the gas will get hot enough to burn off.
Then I'd put some Sea Foam in the gas to clean up all the goey crud that the cylinder(s) surely has/have.
Then I'd start worrying about other things like points and all which possibly requires the removal of the flywheel.
When I accidently ran My 88 50hp Evinrude at 100:1 it eventually developed a knock.
The Top cylinder only required a rebuild.Bottom was untouched.
Bottom cylinder must have bee everso slightly richer.
Another possibility is you may have a bad fuelpump diaphram leaking fuel into the crackcase.This usually affects one plug.
lindy46- I will try the spark tester this evening.
Texasmark- I am pretty sure that these NGK plugs were the direct replacement for the Champions that the book called for. Would elevation change what I really should be using? Reno is 4500'. I put Seafoam in with this batch of gas but I don't remember how many ounce I used for the 2 gallons. Can Seafoam be sprayed directly in the carb inlet?
Steelspike- The fuel pump was one of the first things I took care of with a rebuild kit. New gasket and diaghram. EXCEPT the check valves. Maybe I try those?
How about the float level? Maybe try and get the float lower?
