Engine won't go over 1900 rpm

[mwolson1975]

I have a 1984 Bayliner with a 305. I can not get the rpm's above 1900. It just spits and sputters when I try to go above that.

I've put new spark plugs, wires, distributor cap, points, and condensor on it with no change in performance. Any other suggestions?

Thanks in advance

Mike

 

[Coors]

Re: Engine won't go over 1900 rpm

fuel filters

 

[mwolson1975]

Re: Engine won't go over 1900 rpm

yeah, I replaced the fuel filter also.

Other thing I didn't mention is I did check the timing. 8 degrees BTDC sound about right?

 

[Boomyal]

Re: Engine won't go over 1900 rpm

8 deg is good. Does it have a screen or ball check in the pickup assembly in the tank? They could be cloggged or gummed up.

 

[Coors]

Re: Engine won't go over 1900 rpm

who has Don's fuel system test? I can't find it.

 

[mwolson1975]

Re: Engine won't go over 1900 rpm

I checked the fuel pick up. It has a ball valve, no screen. All appears to be functioning properly.

 

[Coors]

Re: Engine won't go over 1900 rpm

I have a 1984 Bayliner with a 305. I can not get the rpm's above 1900. It just spits and sputters when I try to go above that.

I've put new spark plugs, wires, distributor cap, points, and condensor on it with no change in performance. Any other suggestions?

Thanks in advance

Mike

What is spitting?, backfiring?

 

[mwolson1975]

Re: Engine won't go over 1900 rpm

Yeah, that's what I meant. It sometimes backfires but not real often. It mostly just will not go any higher than about 1900 rpm. I've tried easing past that point and it won't go. If you watch the tach, it bounces up and down about 300 rpm.

 

[Maclin]

Re: Engine won't go over 1900 rpm

Sounds like internal carb problems. When was the last good rebuild on the carb? Any gas/filter/water problems since then? or long periods of sitting?

 

[mwolson1975]

Re: Engine won't go over 1900 rpm

I've had the boat about 4 years and haven't touched the carb. The problem started the last time out on the water last year. It ran great all day and on the way back to the boat ramp. After I dropped people off at the dock to get the trailer, I backed out and was going to run around until the trailer got there. From that point on, I've had the same problem. It's weird because it ran great all day until that point.

Do you think the carb would develop problems all of a sudden like that?

 

[Coors]

Re: Engine won't go over 1900 rpm

The carb, upon backing, could have ingested crap in the bowl.(crap in the tank moving to the pick-up)
Old plug wires leaking and cross-firing.
Distributor needing attention.
Timing.
I would start at fuel first, then track the rest down, it all needs attention each year, anyhoo

 

[Bondo]

Re: Engine won't go over 1900 rpm

who has Don's fuel system test? I can't find it.

Ayuh,.........

Right Here,........

 

[Coors]

Re: Engine won't go over 1900 rpm

Thanks, Bond
still a little slow on how to save links

 

[mwolson1975]

Re: Engine won't go over 1900 rpm

Thanks guys!

I've replaced most of the electrical so I guess the next step is the fuel as you suggest. I'll give it a try and see where I end up.

If anything else comes to mind, let me know.

I appreciate the help.

Mike

 

[180shabah]

Re: Engine won't go over 1900 rpm

It's weird because it ran great all day until that point.

Do you think the carb would develop problems all of a sudden like that?

Not wierd at all, everything is fine until a piece of trash that is big enough to clog a passage finds it's way in there.

 

[mwolson1975]

Re: Engine won't go over 1900 rpm

Wouldn't the filters catch anything that big? If everything is clean up to the filter, then I would think anything past that would be fine too?

If the boat had been sitting for a long time and the fuel deteriated, then I could definitely see a problem, however it ran almost every weekend all summer long just fine.

You guys know more about this stuff than I do so I'm going to test the system as suggested. I'm just trying to think this through with more experienced people listening to steer me back in the right direction when I veer off.

I still am suspect of the electrical system. Maybe I installed the points or did the timing incorrectly, however, I think I did everything right.

One thought going through my mind is in regard to the centrifugal advance? I'm thinking that since it idles fine up to about 1900 rpm's, maybe I have issues on the top end electrically. Your guy's thoughts?

Thanks again

 

[Maclin]

Re: Engine won't go over 1900 rpm

I am pretty sure the timing advance would not limit the rpm like that. It would just rev slower.

The carb is after the filters, and has material inside of it that can fail and cause problems. I had an outboard that the carb gasket deteriorated inside and chunked off a piece right into the main jet. Started and idled fine and revved in neutral, wouldn't get off the trailer without dying.

In my opinion it is time to take the carb apart and take a look.

 

[mwolson1975]

Re: Engine won't go over 1900 rpm

Still at it.

I went through the fuel system and everything appears ok. Rebuilt the carb (which looked extremely clean) and still had no change in performance.

What's next? Compression test? Could I have a stuck valve or ring problems? Not sure what else to do at this point?

Any tips are appreciated.

Thanks

 

[John_S]

Re: Engine won't go over 1900 rpm

You should be able to see some advance before 1900 rpm. Just watch it with timing light.

Reverse at the ramp... Did you take a large wake as you were reversing? Don't know what drive system you have, but you might have took some water up the exhaust. A compression test wouldn't be a bad thing at this point.