87 OMC 4.3L 4bbl Rochester

[JustMrWill]

FINALLY after many months of working on it and $1k left at the shop - had to get flywheel and starter replaced, I got her on the water (fresh) last Wed. Ran great except for bogging down at about 3800 RPM (just shy of full throttle). I figure that it is just a carb adjustment and I can live with "not quite 100%" for the weekend.<br /><br />Took her out Sunday (saltwater) and could only get it up to about 2500 RPM (18-20 MPH on GPS - speedometer not working yet) - throttle at about 3/4. Any more and it would sputter and back fire and stall. After doing 2 dives...on way back...maxed at 2100 RPM and was averaging about 10 MPH (long trip back)<br /><br />Prior to taking her out for the first time I drained all the gas from the tank and put about 10 gallons of fresh new gas. I added another 20 gallons before this trip and had my diving equipment with me (so had a heavier load).<br /><br />Any suggestions as to where to start looking would be greatly appreciated. Thanks in advance.<br /><br />-JustMrWill

 

[elpaso]

Re: 87 OMC 4.3L 4bbl Rochester

Not getting fuel ?<br />Pull your fuel filter - water separator. Pour into a transparent bottle. Look for water and debris. Replace with new.<br /><br />On Rochester Quad - there is a small inline filter where fuel line enters carburetor- check and clean. This takes 2 wrenches - 1 to <br />hold filter housing -2nd to loosen fuel line.<br /><br />Is everything normal -temp. - oil pressure -voltage.<br />Post findings. This is a start.

 

[JustMrWill]

Re: 87 OMC 4.3L 4bbl Rochester

Will be checking filters in next couple of days...will get back with results from that.<br /><br />Oil pressure at about 70-75 psi<br />Temp - steady in middle of green (? degrees)<br />Voltage - when running about 14v...not running...variable...battery doesnt seem to be charging so slowly drops...was down to about 10v (and I swapped out to spare battery I had onboard) soooo.. that is yet another problem I have to look into.<br /><br />Thanks for the reply.<br /><br />-JustMrWill

 

[JustMrWill]

Re: 87 OMC 4.3L 4bbl Rochester

Checked fuel separator last night - very little debris and no water...switched out to new separator anyways. Carb looks alittle gunked up. Will be pulling it and cleaning it (will check filter at that time) tomorow or Friday.

 

[Chris1956]

Re: 87 OMC 4.3L 4bbl Rochester

Just - Also check the filter on top of the mechanical fuel pump. My '88 has one of those filter stones that GM liked to use.

 

[JustMrWill]

Re: 87 OMC 4.3L 4bbl Rochester

Thanks...is it easy to get to or do I ave to remove fuel pump?

 

[JustMrWill]

Re: 87 OMC 4.3L 4bbl Rochester

Ok...finally got a chance to take a look and guess what I found? The distributor retaining bolt had lossened and my ditributor moved back and forth freely. Goona re-time and thread lock that bolt ...should be water testing tongiht or tomorrow night. Will let ya know.