Logo
FULL SITE MENU

1987 350 270 engine problems

H

henryf

New member
need help trouble shooting a problem, my starboard engine when power applied will pull good till about 1800 rpm than eng starts cutting out, rpm goes up and down than finally quits. changeed the fuel filter no difference, at the dock in neutral eng runs perfect took it to 3500 rpm several times no problem anyone have any ideas
 
Had a problem like yours same engine but an 89, check the electrical system coil, points etc. I have a EST ignition and it was a wire out of the points that was shorting out at 2000 RPM's. If the carb or fuel system is bad it will be bad thru the entire RPM range not just under load and in gear.

Thats my 2 cents it drove me crazy.
 
You mention "electronic conversion" kit.
I'd encourage you to NOT do this.

1..... this is likely the Pertronix kit.... (Hall Effect... magnets encased in a plastic unit and a cheezy sensor).
2..... this does ZERO for any wear that may affect the operation of the advancing system.
3..... there are much better systems available..... such as VR that the Mallory, and some others offer.

I'd only do the Pertronix conversion if on a tight budget, and ONLY if the distributor was sent out for re-calibration.

As for your engine issue, use the tried and proven P of E.... (process of elimination)....., and one item, and one item ONLY until you find the issue.
If you take these one at a time.... (apposed to throwing all sorts of parts at it), you'll learn exactly what the issue was, and you'll be better equipped to diagnose a similar situation in the future.

.
 
Last edited:
I just had this problem on my 1980 270 port side engine. Corrected the problem as follows:

a. Changed fuel filter at carburetor
b. Replaced mechanical fuel pump. Use caution with this change, as the push-rod position must be held at the cam lobe or you will bend the push-rod.
 
Henry
Let us know if your distributor tune-up works.
I am having exactly the same symptoms with my port engine. I have replaced points, condensor & rotor but no improvement. I am about to change cap and wires as well.
I recently replaced my broken fuel pump and filters are new but have not checked the anti-siphon valve on fuel pick-up.
 
You mention that you changed the fuel filter. I had the same engines a while back and believe there was more than one filter per engine. Also, did you dissect the filter to see if there was crud inside? Bob
 
Temporarily connect a six gallon outboard fuel tank to the fuel pump inlet and see if the problem still exists. This will eliminate alot of guessing.
 
Ignition related problems usually result in a "Jerky" miss whereas fuel related problems usually result in a gradual and smoother loss of power as the rpm increases. When the engine quits, immediately check for spark.
 
Back
Top