'91 90HP wont go above 1400rpm (long) suggestions please

pontoonski

Recruit
Joined
May 21, 2004
Messages
3
I just dumped in today, first time this season. I've only owned the boat for about 10 hours (last season) and here is my situation. Last fall I used it briefly. Had a marina put some gas in during that 10 hours last season and at that time they also added the 2 stroke oil to the gas. Ordered the Clymer manual to do a winterization and read that the motor has an oil injection and that the gas does not need mixed...more on that later. Anyway, it ran beautiful until I took it out last fall. Winterized it according to the Clymer manual. Start it up about 2 weeks ago and it ran perfect. I trailer the boat to the lake it's used in and figured I should fill up on gas at $1.99 while I can. I do not add any oil to the gas. I dump in today, start it and let it rev at about 3000 rpms for a couple minutes, idle down, let the lines loose and proceed to motor down the river at idle. I then get to the mouth of the lake and try to give it some gas and I get nothing as far as rpm's. It feels almost like the throttle cable broke. I idle back to the dock and see that the throttle is moving the lever on the engine. My uneducated guess seems to be that it either running very rich like the choke is stuck or maybe too lean and the engine is electronically holding back to protect itself. Does anyone think it could be that I did not add 2 stroke oil to my gas? The oil resevoir on the side is filled and it was working last year even with the mix gas as I did get a low oil warning beep the last day of use. Everything was running perfect up until what seems *to me* that the old (mixed) fuel ran through the lines, and the new unmixed fuel reached the engine (About 3-5 minutes of running). Heading back tomorrow (Sunday) after posting here on the forum and cracking the Clymer manual for suggestions. The engine starts and idles just fine but I can not get any revs past 1400rpm. There are no warning beeps suggesting low oil or overheating. What could have happened to where I launch and it runs great in neutral even up to 4000 rpms to just a few minutes later to where there is nothing? Maybe the injection pump wasn't working to full capacity but ran fine on a gas mix?? But would this situation of straight gas cause the engine to not rev at all?? I have no excessive smoke but to see small oil splatters (like light rain) appearing behind the motor. Any help greatly appreciated. TIA
 

hondon

Lieutenant Commander
Joined
Jun 11, 2001
Messages
1,922
Re: '91 90HP wont go above 1400rpm (long) suggestions please

Try running on a different fuel source,a portable tank .You may well just have critters living in your fuel tank vent and not allowing it to do the job.What happens if you squeeze the primer bulb or activate the choke/primer on this unit?Just because the engine came with oil injection ,do'es not mean your engine is still using it .That you will need to find out.
 

pontoonski

Recruit
Joined
May 21, 2004
Messages
3
Re: '91 90HP wont go above 1400rpm (long) suggestions please

With the neutral throttle all the way up (i.e. should rev to 4000 rpms) it runs at about 1400. When I depress the key to activate the choke their is no difference, when I squeeze the gas bulb, again no difference. I did some thinking and thought about a possible clogged fuel line/filter. Will do some looking today. It's just unusual that it reved just fine during it's first warm up of the season and then a few minutes later nothing. Maybe something worked it's way into clogging something? Maybe it is a fuel/oil issue. Thanks for the suggestion of trying a portable tank.
 

pontoonski

Recruit
Joined
May 21, 2004
Messages
3
Re: '91 90HP wont go above 1400rpm (long) suggestions please

Well I tried a portable gas tank with some mix to no avail. I talked to the marina's service guy and he said it could be several things but suggested it might be the stator. So I put in a work order for the marina to look at it this week. Still no revs above 1500. I'll keep the group posted.
 
Top