2001 Yamaha 115 4 stroke has problems starting and bogging on a load

Joined
Apr 22, 2011
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1
I just recently bought this boat and has run fine the first 2 weekends, then last weekend... boat had a lil problem starting at the ramp. its seems when turning the key to start it turns over..and over and as soon as i let off the key its started. all seemed fine...till went to get it up on a plain. it would bog down and the more throttle i gave it the worse it bogged down??? Checked the bulb...Tight.. checked the water seperator...no water. then the filter on the motor...red ring still on the bottom and no water in that as well??? the previous owner had lost the original key and had been using a regular metal key to start for months...no problems?? any suggestions?
 
Joined
Oct 28, 2010
Messages
923
Re: 2001 Yamaha 115 4 stroke has problems starting and bogging on a load

Sounds like a fuel issue, if you put a new key (will have to put new key switch in as well) make a note of the key number and keep it safe somewhere, that way if you lose it you can replace it easy. First you need to ensure you don't have a fuel restriction, hook up a fuel vacuum gauge to the output side of the filter on the engine just before the fuel pumps. You should not see more than 4"hg. After this is verified check the fuel pump pressure at the VST you should see 44 psi (it may drop a little once the fuel pump stops but should stay at a steady 36-40 psi for a few minutes) with the key on, once the engine is running you should see about 35 psi, this means that the regulator is working by reducing the fuel pressure.
 

Bamaman1

Lieutenant Commander
Joined
May 15, 2011
Messages
1,895
Re: 2001 Yamaha 115 4 stroke has problems starting and bogging on a load

Make sure you're getting fuel. Check the fuel filter next. See if the spark plugs are fouled. Then, pull the carbs, disassemble them for cleaning, put'em back together and watch it run good. It's often the needle valve getting stuck from non-use over the winter--or dirty carbs.

On 2 strokes, there's no rebuilding of carbs--just cleaning them. They're simple, and no kits or gaskets are usually needed if you're careful.
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
8,851
Re: 2001 Yamaha 115 4 stroke has problems starting and bogging on a load

the previous owner had lost the original key and had been using a regular metal key to start for months...no problems?? any suggestions?

I believe the plastic hood just fits over the metal key to help keep moisture out of the switch, if there is a problem with the switch then it would need to be replaced, but the plastic/rubber cover would be a good thing to put on also.
 
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