Boat will not stay running. Please Help Fuel issue?

[jstatham]

Ok guys I need to pick your brains again. I have a 88 Johnson VRO. The boat has been sitting for three year so I have rebuilt the carbs, replaced the plugs, changed the foot oil, new fuel pump (non VRO style), fuel filter, new fuel line. Ok now for the details. I took it to the lake today to test it out. It will idle fine but after a minute so it would die. I then feel the fuel bulb and it is soft. I then pump it up and it runs fine again. So I had my dad drive while I squeezed the bulb and it ran fine for a while. I thank I may have squeezed it to much and flooded teh engine. A few time we had a hard time getting it to crank back up. So I figured the issue was the vacuum line on the Non vro pump since I had to use a smaller size fitting than the hose. I took the fitting off and replaced with the correct size and the fuel bulb still got soft. I then changed the fuel line and put the old line back on thinking the bulb was the issue. I got the same thing. I then removed the fuel selector that has a main and reserve and hooked the old line straight up to the tank. I then nursed it over to the ramp and it ran ok. Once again I was squeezing the bulb. Once hooked to the trailer I stopped squeezing the bulb and ran it wide open and it would not go dead and the bulb was tight.. I am stumped on what could be the issue. I then got home and removed the fuel pickup from the tank and it looked fine. It look like a big straw and the hole was too small to see in it. It has a 10 gallon built in tank. The only thing I can think of is that there is a bunch of sludge in the bottom of the tank and when I had it hooked to the trailer and a steep angle and it was able to pickup fuel? I tried the main and the reserve and all did the same thing. I had a full tank of gas by the way. What should I try next? Is this a fuel issue? I disconnect the fuel line and turned it over and fuel was pumping out of the pump. I am going to try and go back to the lake this week and take a test tank and hook up a different line and see what happens. DO you have any thoughts or suggestions that may help. I have to have this boat ready it a week to pull 300 miles. Thanks in advance

 

[jtexas]

Re: Boat will not stay running. Please Help Fuel issue?

A restriction between tank and bulb, the fuel pump would suck the bulb flat.
The only way you could flood the engine with the primer bulb is if the needle valves on your carbs are leaking. When the carb bowls are full the valves close and you can't pump more fuel into them.

Did you replace the needle valves & seats when you rebuilt the carbs and adjust the floats? inspect the carb bowl gaskets, make sure there's no leaks.
and the fittings from bulb to fuel pump to carbs, make sure it's not sucking air.

Good thought on using a test tank - whatever other problems might or might not be present, that fuel line has to hold pressure for it to run right.

 

[tashasdaddy]

Re: Boat will not stay running. Please Help Fuel issue?

did you remove all the jets, and clean till sparkling. removing the jets requires a special tool (that can be made from a quality screw driver) you have a fuel restriction,
http://i155.photobucket.com/albums/s311/frankr_photos/FixedJetScrewdriver2.jpg?t=1177353186

you also did not mention you changed two of the most important parts. the impeller and t-stat, the heart of the cooling system. the impeller is rubber and dries out, and will fail at the most inopportune time, and possible cause real damage to the engine.

 

[jstatham]

Re: Boat will not stay running. Please Help Fuel issue?

Ok when I rebuilt the carbs I was able to remove all the jets on all three carbs except one but I cleaned it very throughly and yes I did replace the needle and seats and the floats were set correctly I believe If I remember correctly 3/4 in but I did it by the book. I checked and rechecked and I did not see any fuel leaks. I ran it again when I got home and it idled fine and I could not get it to go dead. I am not sure what do try next. I did not replace the impeller or thermostat because the guy said he just did the impeller before he let it sit up. It pumps water very well and it is not overheating. I also read that changing the thermostat is a real pain? What should I try next. Is there anywhere that has a test tank you can use?

 

[tashasdaddy]

Re: Boat will not stay running. Please Help Fuel issue?

running on muffs, does not put backpressure on the exhaust. should idle around 850 on muffs, when in the water should idle at 650-700 in gear. you may need to set your idle up or the throttle stop screw. a 3 year old dry impeller is flirting with trouble. if you don't have tach, borrow a timing light with the tach feature.

 

[jstatham]

Re: Boat will not stay running. Please Help Fuel issue?

It will idle fine. I think I may have figured it out. Tell me what you think. When I removed the fuel selector and hooked the fuel line straight to the tank it did not run well at first. After I pumped the bulb a few times it ran great. I backed it up to the trailer and loaded. Once on the trailer I put it in gear and ran it wide open for several minutes and it would not die. I am wondering if I had air the in the lines and when I removed the fuel selector the air worked itself out and it started working? I did notice the line for the fuel selector was loose and I could just pull it off by hand. So I thank it was sucking air there. Does that make any sense? I need to take back to the lake and give it another test. Any comments?

 

[jtexas]

Re: Boat will not stay running. Please Help Fuel issue?

3-gal plastic tank plus fittings, a few bucks at walmart. friend with portable tanks, free.

If you pumped the primer bulb up right now, then checked it in a couple hours, would it still be firm? if so then sounds like your loose line was probably the problem. If it was me, I'd take her back for a test run before that 300 mile trip.

About the impeller, those vanes develop "memory", so after being immobile for so long it'll be less effective than when it was put away 3 years ago. But I guess you know the consequences of a failure - I'd at least keep a close eye on the pee stream.

 

[jstatham]

Re: Boat will not stay running. Please Help Fuel issue?

I have a 6 gallon tank that I am going to try this week. I also ordered an impeller. How difficult are they to put in. I have 2 days that I can actually work before I leave and I just cant afford a screw up. I have read where people have messed up the main rod putting in the impeller and having issues? I don't know if I can risk it. I can always carry he impeller with me and watch the pee stream.

 

[iwombat]

Re: Boat will not stay running. Please Help Fuel issue?

The impeller itself isn't a tough job. Where most people run into problems is separating the LU. Make sure to read where all the bolts are (there's a couple hidden ones). Also, if it hasn't been serviced in awhile it may have some stubborn fasteners, or a sticky drive shaft.

Once you get the LU off, the impeller is a snap.

 

[jtexas]

Re: Boat will not stay running. Please Help Fuel issue?

yup...first step is disconnecting the shift rod up under the bottom carb...trim tab has to come off, there's a bolt up under there, mark it first so you can put it back in the same orientation...a little dab of dish soap will hold the pump housing gasket in place while you position it...manual calls for "OMC adhesive M" or something like that where the L/U joins the midsection, I use permatex #2. Make a mental note if the inside of the housing is scored, any noticeable marks at all, like if it's been run in gritty or sandy water, you'll want to do a full pump kit on your next impeller change.

 

[jstatham]

Re: Boat will not stay running. Please Help Fuel issue?

OK guys I want to thank everyone for there help and I thought I would give an update. There were actually 2 things wrong. #1 the fuel selector was sucking air. Also the replacement fuel filter I bought was for a 1/4 inch fuel line and not a 5/16. I hooked the fuel line directly up to the tank and put the old filter back on. I the took it back to the lake and it ran awesome. It purred like a kitten and idled great. I ran it for about 20 minutes and loaded it back up. I guess the next questions is should I mess with changing the impeller before my trip. I ordered one yesterday but I am hesistant on replacing because I don't want to mess it up. I may carry it with me just in case. I am also going to replace the fuel filter with a 5/16 size filter. Thanks again for all your help.

 

[jtexas]

Re: Boat will not stay running. Please Help Fuel issue?

First impeller change can be intimidating, but you can do it (with a manual). Since you have no history with this motor, you don't know how strong it pees with a new impeller, can't judge whether it's deteriorated. I hate to think about waiting till it fails to replace it. If you decide to wait, test your overtemp horn. Come to think of it, test the horn anyway.

 

[jstatham]

Re: Boat will not stay running. Please Help Fuel issue?

How do I test the horn? Where is it located?