Posts: 8
| I have a 1995 Evinrude 70 that is running terrible. Will not run at low ram in gear, but idles fine when warmed up. As soon as I engage the gears, whether forwards or reverse it kills the motor. I have had carbs rebuilt, new Reed valves tune ups, tried several fuel additives, nothing has worked. I would greatly appreciate any ideas you can give me. |
Posts: 3472
Location: Elk River, Minnesota | Hiya!!
There are a few things that this can tie to, so going through a checklist might be a good thing...
I think the first thing I would consider is how does it sound at idle...is it really smooth or does it sputter at all when it is warm? If it sputters a touch, it could be many different things, but I'd say start with some easy checks/indicators.
First. Pull the plugs...are they all uniform in color and the inside light brown? Are they black and wet or are they white and dry? Are they all the same or does one stand out differently than the other two? These indicators tell whether or not other issues are going on. If one plug is bad, it will have lots of deposits as compared to the others.... No matter what, I'd replace them yearly as they are fairly inexpensive and retest. If it is still running rough, then pull all the plugs and and check for spark...if one does not spark or is weak (do this with new plugs) , it could be the power pack as Steve Worrall mentioned.
If all the plugs have lots of deposits on them but have spark, it could be that your engine is just gunked up with carbon. If this is the case, decarbonize the engine (explained at the end). After you have completed a decarbonization process, replace the plugs.
Second: If changing the plugs does not do it, then if you can, find a timing light and check the timing. Your motor sounds a bit like my 99 Johnson 50hp that did the same thing...it would start, and once warm would idle fairly well, but then would die as soon as I put it in gear. I made the timing adjustment and she purred like a kitten. Instant start as well. If memory serves me, that engine should have an idle speed of roughly 800 rpms and the #1 cylinder (top cylinder) should be at 0 degrees TDC. If it is off, adjust.
If Timing is on and decarbonization is complete, then it is time to look at carb adjustment if the engine is running a tad rough... adjust each fuel/air needle screw 1/8 turn clockwise and see how the engine sounds. If it is worse, go back to original positions then adjust 1/8 turn counterclockwise. If worse, then your original position is correct. This should be quite noticeable.
My gut instinct says this is either carbon deposits or a timing issue. Do you do a lot of trolling?
To decarbonize the engine:
Get a can of pressurized seafoam and remove the air baffle in front of the carbs. Get the engine running and warm. Then, spray about 1 - 2 second squirts into each carb and repeat this about 4 -5 times in each carb. The engine
will start to sputter and burn white smoke. Now...spray about 4 - 5 seconds into each carb, shut off the engine, then spray another 4 - 5 seconds into each carb. Let the engine sit for about an hour.
Once the engine has sat for a while, take it out and open it up...get all the white smoke cleared out, then change your plugs... This is something that is good to do at the end of the season if you are running a carbed 2 stroke as they fuel/oil ratio is potentially much higher than the newer 2 strokes.
Steve
Edited by VMS 10/26/2020 7:17 PM
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