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OB Issues - Dies when shifing to Forward

S

Sjolie

New member
Hi I have a 3 year old Tohatsu 4hp, which has been plagued with problems. I've definitely had fuel issues throughout last year and had it professionally serviced this year. It is used on a smaller sailboat (19'), so runs mostly out the channel and back in, about 200-300 yards each way.

This weekend I was so happy that it fired right up and idled at the dock for 5+ minutes. Pulled away from the dock in reverse, spun around and headed for the channel in forward. About 1/2 way out the channel she just died. Started up pretty well in neutral, then when shifting to forward dies. Repeat over and over.

Sailed for a few hours, then needed to head back in, same problem. This time, however, my friend was able to coax some effort out of the OB by playing the choke as a throttle so we did make a bit of distance in the channel, but of course she died on the way in so we came back to the little harbor / ramp area under sail (which worked out pretty well I'd say).

I'd love ANY thoughts on this. I'm not very mechanical, but willing and able to learn!

Thanks.
 
Your situation could be a number of things, but sounds like the classic "too lean in low speed" problem, caused by deposits in the idle and transition circuits of the carb. Do you religiously run the carb dry at the end of each and every day? If not, you definitely need to do that. As part of the professional servicing, was the carb removed, completely disassembled, submerged in real carb dip for 4 hours, then blown clean with carb spray, and reassembled? If not, you could probably benefit from a good carb cleaning. Or... since the 6 hp carb interchanges directly, it may be more cost effective to just replace the carb. I keep one on the shelf at all times, for just such an occasiopn. 3R4032001M CARBURETOR ASSY, MFS/NSF6A2 $116.52. And yes, it will indeed turn your motor into a 6 hp model.
 
Thanks Paul. I agree, it definitely runs too lean. Until recently I did not know to run the carb dry at the end of a days use; so there are a good couple years of use that I was not doing that. I'm really intrigued by the idea of replacing the carb, especially if I can upgrade to a 6hp by doing so. I'd like to contact you directly if that is OK. I'll send a message via the site. Thanks again for your help.

Sean
 
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