[wrj9892]

We are new to boating and just bought a used boat with a 78 Evinrude 175 outboard motor. The previous owner had rebuilt the motor over the winter and assured us it ran great. The first time we took the boat out the motor cut out every time we tried to throttle up to full speed. He took the boat back and has since rebuilt the carburetors again, checked the fuel lines and tank, replaced the fuel filters and pump, and changed the gaskets. It runs better, but we're still having problems. Now its a little balky at the start, but gets up to full throttle. However, when we slow down for a long time or shut the motor off, we again have the problem of not getting up to full throttle. The previous owner and a outboard mechanic friend of his are at a loss for what is still causing the problems. Any suggestions?

[wrj9892]

Additionally...does altitude have any effect on this problem. The boat will primarily be used at lake which is about 5000 feet in altitude.Still searching Wendell

[almost retired again]

9882, Did the boat come from a lower altitude? If so the carbs may have to be re-jetted to keep the air/fuel ratio proper. If it's an air jet go larger, if it's a fuel go smallerGood luck

[wrj9892]

Yes it was adjusted in town here at about 2800 feet. Thanks. I'll check on this.Wendell

[wrj9892]

Does anyone know a good motor shop in Boise ID? I think its time to take this thing in.

[wrj9892]

Finally order the service manual. Hopefully something will show up. Taking it out again this weekend. Question - The throttle plates look like they are close, but not quite in the same position at full throttle. I'm only talking about 1/16" to 1/8" difference between them. Is this enough to contribute to the problem.