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Tohatsu 9.9 2 stroke wont rev in gear

D

Danielc

New member
Hi, newbie here. I have a 9.9 2 stroke tohatsu motor. I think is around a 1996 model. It seems to start and idle ok. But put it in gear, it wants to rev for a moment and then dies down and runs just above idle. It wont rev to full power in gear, but will rev out in neutral. I have pulled the carb and jets apart and cleaned them, but no joy. Plugs look ok, and have spark. Im thinking possibly the fuel pump might be dodgy. Just wondering if anyone else has had this issue.
 
Does spark jump a gap of 5/16" ( 8 mm ) or more ?------What does a compression test show ?-----What happens if you operate the manual fuel pump ?----Sounds like it is running on one cylinder.-----Most motors will rev up in neutral , really means nothing and it would rev up on 1 of 2 cylinders.
 
At one point when i squeezed the primer bulb, it picked up a few revs and seemed like it wanted to go harder. Dont have a compression tester, and didnt look that closely at the spark, other than to check each plug was sparking.
 
It is a 1996 model 9.9D. I fully stripped the carb and fuel pump, cleaned with carb cleaner, and ran a thin piece of wire through each jet to make sure there was no excess gum etc, that hadn't been removed by the carb cleaner.
 
M9.9D2, eh? You should redo the carb. Complete disassembly, then soak all non-rubber bits overnight in real carb dip, then blow out every passage with tons of generic carb spray. The spray is not aggressive enough to soften the organic deposits in the carb by itself. Never use any wire, as it can scratch surfaces, and cause weird mixtures. What do the plugs look like? If they are too clean and dry, you are too lean.
 
Thanks. Been thinking about picking up a brand new carb and fuel pump assembly off ebay. They seem pretty cheap. The plugs look pretty good. Not too lean or anything. Might take it for a run romorrow and spray a bit of fuel down the carb at WOT and see if it makes any difference. At least then i can confirm it is a fuel issue.
 
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