Poor acceleration, no WOT

[calwldlif]

Re: Poor acceleration, no WOT

There isn't much info here.
Guys rightly suspected water.
If I understand your discription
boat is running rich?
Bogging sound?
Smooth but no power?
Choke?
Carb power valve?
Please discribe what feels like pulling a boat.
what sounds does the engine make?

 

[GRHoward]

Re: Poor acceleration, no WOT

Have you rechecked your tune-up. The amount of hours is about right for a cracked insulator on a sparkplug. A cracked insulator would let the plug fire well enough to start and idle smoothly but fail under load. You could use a scope to analyze the spark or you could just put in a new set of plugs.

 

[bronxlatetour]

Re: Poor acceleration, no WOT

Tune up was done less than 10 hours ago. Coil has less than 3 hours on it. The boat struggles to get on plane now. I used to hit the throttle to about 3/4 to get up on plane and the RPM's would climb as we accelerated, I would actually have to back off the throttle as I got on plane. Now I have to give full throttle and the rpm's go to about 3000 and seem to struggle. When I slowly get on plane then they will rise to a max of about 3700-3800. I also hear the secondaries opening up sooner on the carb.

 

[kimchee]

Re: Poor acceleration, no WOT

Did you try messing around with the outdrive trim a little to see if you get some out of the ordinary sounds? maybe your outdrive is not aligned... After mentioning you VERY SLOWLY backed into sand, its kinda hard to ignore that as a possible culprit...

 

[bronxlatetour]

Re: Poor acceleration, no WOT

I had the boat out today, same deal. I've trimmed the drive with out problem. No unusual sounds/vibrations. Today at one point while cruising the RPM's wouldn't go above 3400 and it sounded like it was running very rough. Could this be a carb issue? If so, would it occur out of the blue? Wouldn't it be a gradual decline in performance? I'm lost and frustrated. I also realized that I had some cold start issues as of late. Sometimes I have to crank the hell out of it with the throttle fully depressed to get it to finlly turn over. That's only after sitting over night though. Even on a day trip with 7-8 hours in between it starts fine. Help!

 

[calwldlif]

Re: Poor acceleration, no WOT

I haven't seen where you checked anything.

 

[Bondo]

Re: Poor acceleration, no WOT

I haven't seen where you checked anything.

Ayuh,................ I Knew I was supposed to do Something last night..............

It's getting Tougher,+ Tougher to fly out to all these Broken Boats every night,+ Fix them while the Owners are Sleeping...........

Yes Virginia,........... There IS a Santa Claus.............d

 

[wiredtaz65]

Re: Poor acceleration, no WOT

What type Carb is it? Holley? if so, has the engine backfired recently? Holleys are know to blow power valves in a backfire,Whick causes the engine to run slugish and rich.Pull your plugs and "read" them. What color are they? you can tell a lot from this.If plugs a a light tan color that perfect.

Id then look at the fuel pump to see if it working properly

 

[bronxlatetour]

Re: Poor acceleration, no WOT

I was going to change my plugs today in hope that I would find a cracked one. Before I did, I figured that I would check my wires on the outside chance that one popped off. The first wire I checked had a big electrical burn mark through the side. Totally fried. As I believe that my boat was sturck by lightening 2 weeks ago I think it might have occurred then. Unless this is a common thing to happen on marine engines? I bought a new set of wires and I'm taking the boat out tomorrow. I'm pretty confident that this will solve my problem. I would like to thank everyone for their suggestions.

 

[calwldlif]

Re: Poor acceleration, no WOT

Geeez:|
Did I say Geeez:|
I don't have anything to say..............................
:devil:

 

[Crownie2]

Re: Poor acceleration, no WOT

A couple thoughts:

It's possible the distributor timing has slipped since the tuneup - this will cause a big loss of power. Wouldn't hurt to check it.

Also - check to be sure there is no restriction in your gas tanks vent line. These can get plugged up at the opening. You could also try running it on a portable tank to eliminate any tank/fuel line issues...

Bob

 

[woodrat]

Re: Poor acceleration, no WOT

Gas tank venting has been problematic on two of my boats. In one of them the fuel line was running along the bottom of the boat and then was raised up above the floorboards and then sent back down again (because the previous owner was too lazy to pull up the floorboards to properly route the new line) so it would get airlocked in that bend from time to time. Took a long time to figure that one out!