92 Sleekcraft 26' Enforcer 454 merc - can't get past 3800 rpm on 19P (same with 21P)
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92 Sleekcraft 26' Enforcer 454 merc - can't get past 3800 rpm on 19P (same with 21P)
Bought this 92 Sleekcraft 2 years ago. I didn't launch it last year, but the year before (when I bought it) I was not able to get past 3800 rpm and around 40mph. It had a 19P stainless on it which from what I understand such a small prop should get me way past 4500rpm. I had a 21P stainless but that made no difference.
Things I tried already: confirmed plug wires are good (good resistence); put in new plugs; new cap and rotor; replaced with carbs jets to be a better fit for my altitude (the jet change made no difference).
From what I recall, I did get the occassional hesitation when punching it from a stand-still (sometimes I'd have to give it only half throttle until it revved up a bit and then give it 100% (if I'd give it 100% from a stand it would sometimes hesitiate or stall).
Any ideas?
Things I tried already: confirmed plug wires are good (good resistence); put in new plugs; new cap and rotor; replaced with carbs jets to be a better fit for my altitude (the jet change made no difference).
From what I recall, I did get the occassional hesitation when punching it from a stand-still (sometimes I'd have to give it only half throttle until it revved up a bit and then give it 100% (if I'd give it 100% from a stand it would sometimes hesitiate or stall).
Any ideas?
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Ignition timing. Idle isn't THAT important. But you need 32 ro 34 at WOT. if not advancing, it'll sound beautiful around the dock but have no balls. And that is a largish boat for single 330 hp motor. I think 50 will be it's practical limit. Now, don't beat the excrement out of it today. Engine isn't the only thing with 2 year rest. Watch oil pressure and especially temp. Let it settle in and blow the rust off the bores and rings. Then do a compression test.
Last edited by dereknkathy; 05-16-2017 at 05:26 AM.
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so I had a mech out. He said the timing was way off so he adjusted it and fiddled a little with the carb. We fire it up (still on the trailer in the yard) and he said it sounded nice and said based on the sound he could tell everything was as it should. So I launched it yesterday for the first time in 1.5 years and it did run smooth but still only got to 3900 rpm. I called my mech and he said he thinks it is my 2 barrel carb - he said I should put on a 4 barrel.
Personally I think the mech I choose may not be too good - I knew him from the local car repair shop and he was good on cars - not so sure on boats.
Anyway, your thoughts? Is it unusual to have a 2 barrel on a 454 merc? Is that stock, or perhaps did a past owner put this on? If I do upgrade to a 4 barrel, what can I expect in hp increase? Is a swap easy?
Thanks
Personally I think the mech I choose may not be too good - I knew him from the local car repair shop and he was good on cars - not so sure on boats.
Anyway, your thoughts? Is it unusual to have a 2 barrel on a 454 merc? Is that stock, or perhaps did a past owner put this on? If I do upgrade to a 4 barrel, what can I expect in hp increase? Is a swap easy?
Thanks
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OK, I'm no expert or mechanic, but I just removed my flame arrestor thingy and took a picture of the carb - pretty sure it is a 4 bbl. Anyone know what type this is before I call the mech and give him a piece of my mind - he charged me $200 to come out for about 30 minutes to my house and all he did was set the timing and fiddled with the carb screws a little - he didn't even know the type of the carb after fiddling with it??????
Oh on a side note, I had the cover on so the room was tight. After removing the screw for the flame arrestor I pulled it up not knowing it had a washer on it. I heard the washer fall but can't find it. I'm hoping it fell to the bottom of the engine area - I looked at the top of the carb and didn't see it there. There is a small chance though that it fell into the carb. Your thoughts? If it is there, would it make it to the engine, or just plug the carb?
Thanks
Oh on a side note, I had the cover on so the room was tight. After removing the screw for the flame arrestor I pulled it up not knowing it had a washer on it. I heard the washer fall but can't find it. I'm hoping it fell to the bottom of the engine area - I looked at the top of the carb and didn't see it there. There is a small chance though that it fell into the carb. Your thoughts? If it is there, would it make it to the engine, or just plug the carb?
Thanks
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Yes. It will suck it in and possibly do catastrophic damage. That is a carter-weber-edelbrock afb...four barrel. If you don't find washer, carb has to come off. Then go get a magnet on retractable stick and play go fish. But first, get a flashlight and look down carb for the washer. Don't open throttle.
Last edited by dereknkathy; 05-24-2017 at 09:48 PM.
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Yes. It will suck it in and possibly do catastrophic damage. That is a carter-weber-edelbrock afb...four barrel. If you don't find washer, carb has to come off. Then go get a magnet on retractable stick and play go fish. But first, get a flashlight and look down carb for the washer. Don't open throttle.
So by don't open throttle, how can I see down there cause the flappers are closed. So I can't even open them by hand to look in better? So if I can not find the washer along the side somewhere, you would suggest removing the carb? If I remove it, wouldn't the washer fall into the intake holes?
I'll take a closer look tomorrow - if I don't see anything do you think it is a good idea to try to turn the engine over via pry bar from the main pulley? If I get a full rotation without a snag, is that a sign that I'm good to go?
Thanks
Last edited by dna; 05-24-2017 at 11:24 PM.
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If it is laying on throttle blades and you open them, it will drop in to intake. Pull carb without having opened throttle, and even if you don't find washer, you can be faIrly sure it didn't go down intake. Turn carb upside down, expect about half a cup of gas to run out. Now you can open throttle and shake.
Last edited by dereknkathy; 05-25-2017 at 01:15 AM.