Fuel Issues?

[stocky]

I have a 1988 Merc 150 xr2 that has just been rebuilt. When on the water running at anthing like 3000-4000 rpm the engine will just die or labour. When I back off the throttle and pull it back on it will go OK.This problem doesnt happen immediately as you can run for 10-15 minutes before this occurs. I first thought that it may have been a blocked filter and isolated it but the problem still occurs. A couple of thoughts have crossed my mind:<br />1. Picking up some crap from the tank and blocking the fuel line.<br />2. Sticky needle and seat<br />3. fuel pump issues<br /><br />Look forward to your replies<br /><br />Thanks<br /><br />Stocky

 

[AMD Rules]

Re: Fuel Issues?

Maybe a plugged vent on the fuel tank....starving for fuel?<br /><br />Does it run ok if you squeeze the fuel bulb when that happens?<br /><br />Check all your connections...ie. sucking air at a fuel line?

 

[stocky]

Re: Fuel Issues?

Sorry I didnt mention but on two occasions when the motor was losing revs I pumped the bulb and there was no change.

 

[Laotzu]

Re: Fuel Issues?

Stocky, I went through a similiar problem and found out it was some varnish flakes in one of the carbs. <br /><br />Jerry

 

[stocky]

Re: Fuel Issues?

The boat does have a raycor fuel filter and I would doubt if any varnish would have passed through. What I did think about was that maybe the venting of the fuel tank is blocked or partially blocked. What do you think.

 

[Laotzu]

Re: Fuel Issues?

Could be. In my situation, the boat had sat for 4 years and the varnish was built up in one of the carbs, the one closest to the filter.Had water in the gas besides. Maybe not so strange, but mine would max out at 3000rpm because it was only running on 2 cyl. Sounded ok, but no power. Big problem, but an easy fix after trying a hundred things..<br /><br />Jerry

 

[stocky]

Re: Fuel Issues?

Sorry about the delay in replying, but thanks Laotzu there was a blockage in one of the idle jets on number three carby.