Well, I purchased the 9.5 I looked at last week because it ran great in a tank and the compression, lower unit, etc tested good. I took it out tonight on the lake and the motor wouldn't run right. It seemed as though it was running too rich. It wouldn't rev out and seemed to be 4 stroking. It would try to rev out, and then it would stumble and start 4 stroking again. I am going to adjust the carb, but I don't have any of the specs for it and I can't determine where the adjustment for the high speed needle is. Could someone please tell me how to adjust the carb to factory specs?
Buy a carb rebuild kit for your engine. Remove the carb and float bowl. Remove the float bowl drain, and using the "Special Tool" thats mentioned a lot on here (Its really a small small flat headed screw driver. You can improvise, but do be careful) remove the high speed jet.
Remove both core plugs, the float, needle, and seat. I would suggest soaking the carb parts in carb cleaner at least overnight, but in the past when the inside of the carb didn't look that bad I've use carb cleaner in a can and some compressed air to clean it out. Never had any problems either.
Rebuilding the carbs is one of the many things most people do when they first get a motor. Its cheap (25 bucks) and for me, just knowing that all the gaskets and pieces are new makes me feel better about it.
Your problem may have something to do with spark as well. I would suggest pulling the flywheel and inspecting the coils to see if they are cracked. If they are originals, chances are they are cracked/bad/both. If nothing else, I'd throw a set of coils, points, and condensers in it.
The people here are great, and an immense resource.
I popped the flywheel off, and the coils look good. They are aftermarket with no cracks and still look new. The points are nice and shiny. I gapped them to .020in and reinstalled the flywheel. I am really thinking this is a carb issue. Is there a fast speed mixture screw on the carb that I can adjust. I see the idle speed mixture screw, but nothing else. How can I lean the carb out for top end running? What is the correct setting for the float?
I just ordered a new carb kit to rebuild the carburetor, but I still don't have any info on the carb specs (float height, needle adjustment, etc.). If anyone has this info it would be greatly appreciated. Also, Matt could you please email the manual you have to me at caryhenry@hotmail.com
Another question: will it be ok to get a service manual for another year 9.5hp? I have found some for 1970 and 1972 motors, but not for 1968. Do the models vary much over the years, or is any manual ok?
When it was running rich and 4-stroking, was it on a boat or in a barrel? And was it running with the hood on or off? The 9.5 does not like to run in a barrel, especially with the hood on. It breathes too much of it's own exhaust smoke. Likewise, on a boat if it runs well with the hood off but is rich and 4-strokes with it on, it has an exhaust leak. Extremely common on the 9.5hps. There are several possible leak sources. Come back for more info on this if applicable.
I was running it on a boat when I had the problems. I tried running it both with the hood on and off (to test the leaky exhaust) but it made no significant difference. While running WOT, you could hear the motor try to run higher but then it would back down to the lower speed shortly thereafter. It sounds just like my 55 5hp when I have the high speed knob set too rich.
due to being too rich? or do you think a coil is bad?
On another note, I decarbonized the motor really well today and it seemed to run a lot better. I put some earmuffs on it, and it seemed to rev out all the way in forward. After running the other night I had noticed that the spark plugs were coated in a moist black sludge. After running today they were nice and clean. I'll take it out for a test run before I rebuild the carb to see if it made any difference. Could the problem have been from the excessive carbon build up? I checked the compression before and after the decarbon and it went up maybe 10 psi but that doesn't seem like much to me.
1968 Evinrude 9.5hp Carburetor
Linear Mode
