1975 SeaRay 302 - Wont open up (Hesitation)

[DansSeaRay]

Hello friends,

I have a 240 1975 SeaRay 302 (2 barrel carburetor). Boat starts up no problem. Idle's pretty good. not rough. Going into gear is fine and even giving it a little throttle is fine. When I try to open her up it runs terrible. Sometime I can get it to plane out but most of the time it struggles. Especially after its warmed up. When I do plane it out it only runs at about 3600 RPMs. I have this boat for 3 years and never had a problem getting up to 4000 RPMs. Always ran great from an engine perspective.

Yesterday I pulled the carburetor off and completely tore it down and rebuilt it. Threw it back on and there was no change except now my idle runs a little higher.

Can someone give me some tips on trouble shooting this. My next step was to replace the points. In the beginning of the year i did replace the fuel water separator when i did my typical maintenance.

Please asks questions if you have them.

Thanks

 

[achris]

Re: 1975 SeaRay 302 - Wont open up (Hesitation)

Engines require certain things to operate properly... Basically they need the correct fuel/air mixture to be compressed and then fired at the right time.

So, in this order.

1. Compression tests.
2. Check spark plugs, replace if needed.
3. If points, replace, along with condenser and rotor. Check and adjust, if needed, points cam dwell angle.
4. Inspect distributor cap and leads, replace if necessary.
5. Check spark quality (needs to be a nice BLUE spark drawn over 1/2").
6. Set timing. Check timing advance is working correctly.
7. Check/change fuel filters and check that the fuel system is not sucking air.
8. Check fuel pump pressure.
9. Check for full opening of the carb. Also ensure choke is opening fully when the engine is warm.

 

[DansSeaRay]

Re: 1975 SeaRay 302 - Wont open up (Hesitation)

Thank for your response. I will take back the fact that it never had a problem opening up. Since I had it for three years. I first year there was a couple time where it hesitated but I was able to push through it and then it was fine. Last year it happened more often. About a hand full of times. It does feel like the same kind of hesitation from previous times but now it really struggles.

I did replace plugs 2 years ago. Do you think I need to do it again? The plug wires I don't have a clue when they were replaced. Is there a way to inspect the plug wires or do I just replace all together? How do you check fuel pump pressure?

I will go through your list. Maybe a week before I get to all of it. Camping for the whole weekend.

 

[haulnazz15]

Re: 1975 SeaRay 302 - Wont open up (Hesitation)

I'd suggest starting with the distributor and replacing the points/condenser, and setting your points gap/dwell. Also inspect the advance springs, as those could be causing issue with the timing advance as you increase the throttle. Report back your findings.

 

[slothman]

Re: 1975 SeaRay 302 - Wont open up (Hesitation)

pull the fuel line off the carb and turn it over, you should see a nice stream of fuel. If not, replace the pump.