Poor running engine

[okflyer]

I have a 70's series starflite 115 hp.<br />engine, ran great last year, this year, last weak as a matter of fact the engine idles great,<br />however you have to hold your breath when you advance the throttle and hope it doesen't die.<br />If you play with it long enough it will finally take off, then it sounds like it is loading up or something for a while a couple of seconds maybe then it will peg the tack at 6500 rpm and you have to pull it down to not over rev. it.<br />it seem like the mid range has no power at all.<br />mind you this is on a 15 ft. mod. trihull that was clocked at 56 mph. last year now it won't get out of its own way. any help will be greatly welcomed. also I have had about 15 or 20 parts stores give me different types of plugs to use<br />and nobody seems to agree on anything, I currently run champion l77jc4's any advice on the plugs ?? Thanks in advance Bill

 

[JB]

Re: Poor running engine

Howdy, Okieflyer.<br /><br />First of all, you are either seriously underpropped or you are revving the engne in Neutral. It is not clear from your explanation.<br /><br />Plugs are not your problem. It is likely to be fuel or fuel pump trouble. Clean both carbs and your fuel pump. Put a water seperating filter in your fuel line.<br /><br />Change your prop to one that will not allow the engine to exceed 5500rpm under load.<br /><br />Let us know what you find out.

 

[okflyer]

Re: Poor running engine

bump

 

[okflyer]

Re: Poor running engine

the over rev. condition is in gear this is the prop i was told to use for skiing.<br />and the motor will run wide open until you run out of gas. not even a hint of a problem.<br />p.s. the prop is a 17/3

 

[okflyer]

Re: Poor running engine

bump

 

[okflyer]

Re: Poor running engine

ok here we go. Pulled both carbs. found nothing wrong, nothing stopped up no trash no water, however I did notice the advance mech. was retarded all the way, and would not move.<br />Several years ago i melted down a stator and I guess all that green stuff that had the adv. mec.<br />glued to the hub came from that. I didn't think I<br />was even going to be able to get the nylon bushing off with out breaking it.<br />all cleaned up now and smooth as glass.<br />could this have been the problem?? No adv. no mid range power and falling on its face off idle ??

 

[okflyer]

Re: Poor running engine

bump

 

[okflyer]

Re: Poor running engine

bump

 

[cclemon]

Re: Poor running engine

OK,<br /><br />Yes it sounds like you found the problem. A sticking timing advance would cause the problem you described. It's not too windy today, are you going to try it?