84 SeaRay Seville has hard time after 30 minutes

[HRHVT]

oh, i just remembered. Yesterday I noticed that I had to adjust the idle screw a bit on the carb to get it to start, and to idle at about 750. Then when it warmed up I had to adjust it back because it was idling too high. This was all before i left the dock. It revved up high after a couple minutes

 

[alldodge]

Adjusting idle up then back down leads me to the choke needs adjusting. Should have a 1/8 gap at the top of the choke plate when dead cold.

Disconnect the metal fuel line between pump and carb, blow I out with some air.

You need marine fuel line USCG type A1, not just automotive gas line. You can use auto fuel line for the test if your unable to find it locally, but don't leave it that way.

Don't use starting fluid in the carb, the stuff can break things. Put a small amount of gas in something you can very easily drip into the carb. Something like a pump oil can. This way it is safer and can be added a small squirt at a time. Don't leave the gas in it long term it will damage the pumper.

https://www.amazon.com/Powerbuilt-64...FPYR919SPRMN54

 

[thumpar]

The mixture screw is not for adjusting idle speed. You adjust it for a good mixture and then use the screw on the throttle linkage to adjust the idle speed.

 

[HRHVT]

It was the screw on the throttle linkage that I had to adjust, not the air mixture screw. I think the "butterfly" was straight up and down when the engine is stone cold. But I can double check that later today, if it stops raining. I will run out and take a look. Maybe I can even take some pics if it will help.

Also, either today (if it stops raining) or soon, I will take off the metal line and blow air thru it with a compressor to make sure it is all cleaned out. I'll also change the fuel line from the tank to the pump.

I'll make sure next time I go out I have a small pump with some gas in it, to test it that way,a nd will also see if it gets really hot before it "konks" out.

 

[HRHVT]

So, I just went out and took a look, and sure enough the choke is wide open. seems as though the linkage was a little stiff, not sure how easily it should all move around. I could move it so the choke was closed, but didn't seem as though I should have had to do that. Is there a way to see if the auto choke is working? or should i also spray a bunch of carb or brake cleaner on the outside linkage in the hopes of loosening it up?

 

[thumpar]

When it is cold push the throttle forward. The choke should then close.

 

[HRHVT]

sorry, i am all new to this. When you say the throttle, are you talking about the throttle linkage on the carb? If so, then that is what I did and it closed, but I think it has always been open whenever i checked it, i remember having a hard time starting it before, and manually putting a few drops of gas into the carb, and it was wide open hen too, which may have been why it wouldn't have started.
If it was sticking, then that would explain why i had to adjust the idle to get it started and then back off again a minute or two later when it warmed up a little right?
Would it also explain my troubles after 30 min of cruising at relatively high rpm's?

 

[thumpar]

One the choke is open it will stay open unless the throttle (handle) is pushed forward with a cold engine. I don't think that has to do with the 30 minute trouble.

 

[HRHVT]

Thumpar and Alldodge, thanks so much for helping me to try to diagnose this mystery ailment,

When I get home tonight I am going to check and make sure the choke is closing when i Push the throttle handle forward. Otherwise I will clean the linkage and adjust as to get it to close.

Today I should also be able to replace the gas line (rubber) and clean out or blow out the metal line ot make sure it is clear.

Was thinking of also testing the coil, I have read on here that sometimes the coil heats up and will cause these symptoms, and I justw anted to clear that out of the way.
Do you happen to know what the specs should be for the primary coil, and the secondary coil? I tried to search it out online and could not find anything.

Also, if it is the coil, would it most likely have to be after it failed in order to show up as out of spec?

If so, I can add it to the list of things to check when it konks out on the water.
Ignition coil, temp, spark, etc

Thanks again for all of your help

 

[alldodge]

I don't know what area f it country your in, but if it's 60 degrees or below it should close, when the throttle is moved forward. If it's in the 80's it might not close all the way.

The normal starting procedure for a carb motor when cold, is push the throttle forward in throttle only mode twice, then bring back . Not all the way back just to the forward detent. Once started you can then use the handle to give it a bit more gas if needed.

The choke should be electric and is adjusted with the round dash pot on the side of the carb.

There are a lot of good coils thrown away every year because there cheap and easy. I'll ask to stick with the fuel issue until proven this isn't the issue. If your out there and adding fuel doesn't make it run better, then we can try the electrical side

 

[HRHVT]

I'm up here in Vermont, so it is usually less than 80. Right now it is in the 50's. We don't get enough nice hot days to get out on the boat, which is why it is so frustrating to get out and have it fail. I am ordering some new fuel line 3/8 id and will put that on when it gets here, as well as blow out the steel line. I will also check the choke and make sure it is set up right, as well as adjusting the idle screw if need be.
I like the idea of adding fuel when it fails, should settle it one way or the other, and i hope it is in the right way so i can be finished with it.
Not sure what to look at after it does fail though, assuming by then, i have changed the fuel lines, and the filter, and the fuel pump.
But, we'll see.
Thanks for helping me

 

[HRHVT]

ok, well I cleaned out the metal fuel line, and replaced the rubber fuel line. Also cleaned out the filter inside the carb, although there was only one very tiny speck inside of it.
Also, adjusted the choke so that it actually shuts when you push on the throttle. Seems to be working fine now.
I put the air mixture screw all the way in, and then backed it out anywhere from 1 turn, to 2 full turns. Didn't seem to make much difference, except when i backed it way, way out it would stall.
Meanwhile, I had to put the idle adjustment screw all the way in to get the boat to start and to stay running, It is way more than just touching the metal piece, it is really cranked down.
However, after all of this, the boat did seem to run and stay running yesterday. Usually it would stall after 1 1/2 gallons of gas, about 20-30 minutes. Yesterday we ran it through 3 1/4 gallons of gar, about an hour or more, at 3-3.5k, rpm. Never stalled,
We then floated for about 20 minutes, relaxed, fished a little, and then cranked right up, and ran another gallon of gas getting back to the dock. So, it appears to be fixed, other than the idle adjustment having to be all the way in.
Soon, we will go out and test it again, with about 7 or 8 gallons of gas to be sure.

 

[alldodge]

I had to put the idle adjustment screw all the way in to get the boat to start and to stay running, It is way more than just touching the metal piece, it is really cranked down.

IMO the carb is shot and needs replaced

 

[HRHVT]

Thanks for your help Alldodge,
So, Do you think the 30 min problem could have been caused by the carb also?
I was imagining that perhaps I should get a new carb. Maybe get better gas mileage, better response, etc. The idle screw should be just touching the throttle linkage right? no way it should need to be cranked all the way down.

 

[alldodge]

You mentioned that the idle mixer screw is having little effect and would be all the way out before any change. Then you have to turn the idle screw all the way in and have to crank it down hard to keep it running. Something just isn't right and with everything else I'm thinking its messed up.

Have you done a compression test yet?

 

[HRHVT]

no compression test yet, man i hate to think about that

 

[alldodge]

no compression test yet, man i hate to think about that

Its quick and easy and will let you know a lot about the motors status

 

[HRHVT]

afraid of the test results, but i will have to buy a tester and check it out, seems to run fine yesterday, 3500 rpm's the whole time with no problem, but yeah, i have to do the compression test.

 

[alldodge]

Should be able to get a loaner tool from autozone, o'reillys and others

 

[HRHVT]

Didn't even think about the loaner tool, but bought one online and it was delivered today. Haven't tested the compression,yet, but will do tomorrow.
Did however take it out on the lake today to see what happens. Lasted longer than usual, but still a similar result. Basically ran for about an hour, and then sputtered and died. Poured some gas in while it was sputtering and it kicked it back up. Still ran kinda rough, gave a big backfire, and then revved back up again. Seemed to be fine, headed back to the dock and made it about half way when it did it again, and went thru the same routine. Ran rough, sputtered, kicked back up and then cruised safely back to the dock.
Wondering if now maybe it is the carb needing rebuilding?
I'll get out there tomorrow morning and check the compression, but it won't be that hot when i test it.
What should the numbers be? Or is it just more important for them all to be about the same?
Thanks