Tohatsu M9.9B2----->Struggling under load<-----

[flangler]

Hello,

I'm new to the forum and new to outboards. I got this motor for 400 dollars and its super clean. Starts first pull and idles great. I changed the lower gear oil and entire fuel system(lines, filters, etc...) I even cleaned the entire carb inside and out and replaced the diaphragm. However when under load its struggling to get up to speed. It seems like it's not getting enough fuel. When I manually open it to WOT it will get up and go. Pumping the primer bulb has no effect on engine performance. I always check to see if the vent is open on the tank. I think I'm getting air in the line somewhere. can anybody help me? Is there anything else I should take a look at? Any help is appreciated!

 

[pvanv]

Re: Tohatsu M9.9B2----->Struggling under load<-----

I would verify float height. Keep in mind that there are almost no parts available for that motor any longer.

 

[flangler]

Re: Tohatsu M9.9B2----->Struggling under load<-----

I know! I found that out shortly after purchasing the motor. If I get another year out of it I will be happy. How do you go about measuring float height? Thanks you.

 

[pvanv]

Re: Tohatsu M9.9B2----->Struggling under load<-----

With the bowl off, the float should be parallel to the casting when the carb is inverted (gravity pushing the float towards the shutoff point). Full info is in the Factory service manual, available from any dealer, including me.

 

[flangler]

Re: Tohatsu M9.9B2----->Struggling under load<-----

Ok that is easy enough. I'll give it a try. I'm thinking about going over the entire fuel system on the boat and motor side to check for a leak today. I'll let you know where the float was sitting. Thanks again!