WOT problem, no search success on iboats

[roscottjr]

Took boat to lake for 4th for a day of swimming, fishing, and then watching fireworks. We put the boat in and idled to dock for rest of our group to board. We then started back up, idled out, and then began across the lake at what we are assumeing was WOT for this boat. It is a 1993 Pontoon I believe about 16-18 foot with Johnson 48 hp outboard. Original factory setup and very few hours on engine however engine had not been run in about a year or 2. Originally it would not stay running and after checking everything and cleaning and such we narrowed everything down to a bad carb, replaced the carb and it ran fine. Anyway, we were running at around 4800 rpms and about 5 minutes after leaving the dock the engine suddenly dropped to 3200 rpms. We checked the carbs and both were getting fuel. We disconnected the plug wires while running top cylinder then bottom and each made a significant change confirming that each cylinder was still getting fuel and spark. The engine continued to run great with the exception of only getting up to 3200 rpms. Another family member went back to the lake Saturday and continued to run the engine for about 4 gallons and then went home but said other than not getting above 3200 rpms he had no problems. We checked for overheating and it is not overheating. Also, at idle it will idle smoothly and spit ever once in a while and you can put it in forward it will continue but if you put it in reverse it will idle a few minutes then shut off. This also started after it dropped to 3200rpms. The engine gives no problems at all starting. Fuel is mixed 50:1. I was thinking a lync and sync but it ran fine for about 5 minutes so I figured that procedure wouldnt do any good. Also, when running at WOT of only 3200 rpms if you push the key in (fuel primer) the rpms will jump but this too has quit working. It acts like its starving for fuel but its getting plenty.

Robert

 

[jbjennings]

Re: WOT problem, no search success on iboats

Sounds like you still have a carb problem to me. Especially if choking it helps. Have you pulled the plugs and looked at them? I would just to make sure there's no water in the cylinders. How about your tank vent? have you tried pumping the bulb during WOT or loosening the gas cap on your tank? Did you say you REPLACED the carbs or just rebuilt it/them? Curious...
Just a few ideas,
JBJ

 

[tashasdaddy]

Re: WOT problem, no search success on iboats

"engine had not been run in about a year or 2" any one who thinks an engine should run fine after sitting, with out maintenance. read this, and do it. http://forums.iboats.com/showthread.php?t=158086

 

[mikeyzx2]

Re: WOT problem, no search success on iboats

A simple carb overhaul is probably in order, and if you didn't replace the water pump impeller you might want to, it doesn't take much for one to deteriorate especially after a couple years of sitting. Rule of thumb is typically at the beginning of the season (which I'm a bit overdue as I don't have a "season" here in Alabama). At the same time, change out the lower unit oil, put in new spark plugs, and check out the fuel lines.

Don't want to end up sitting out on the lake with a burnt motor or fuel problems.

 

[roscottjr]

Re: WOT problem, no search success on iboats

"engine had not been run in about a year or 2" any one who thinks an engine should run fine after sitting, with out maintenance. read this, and do it. http://forums.iboats.com/showthread.php?t=158086

Umm, I dont recall saying I expected it to run fine after sitting for a year or two, you said that.

1 Working carb was rebuilt

2 Non-working carb was rebuilt, still didnt work so it was replaced with a new carb

3 Fuel lines replaced

4 Engine has no choke, unless the primer is concidered a choke

5 New water pump

6 New lower unit oil

7 Tank vent clear

8 Primer bulb stays firm

9 Removed Gas cap to confirm getting enough vent

10 Tried pumping bulb while running with no change (I was hanging over back of boat while someone else was driving)

Pulled and checked plugs. 1 is black colored and the other is a beige color but spark is excellent. Not sure what the colors mean on a marine engine though.



tashasdaddy,

I spent over a week going over this engine before we went to the lake. I also have 2 other boats as well as a spare 60 hp outboard. I have searched these forums and followed everything that even remotely sounded similiar to my issues. As far as my post goes, I would not dare post a thread on here to do so much as show a picture of my boat without searching first. I have been ragged by you and other moderators for what you believe is me not searching the forums first. Im sure there are a lot out there who do not search the forums before they post an issue but I for one have read the forum "rules" or "sugestions" whichever you want to call them and would appreciate being treated as one who foloows those guidelines rather than being sent to a thread Ive already looked at and read (in most cases several times) and not even mention anything about my issue. If you like I can take a picture of all the threads I have printed out and post it on here.

Robert

 

[tashasdaddy]

Re: WOT problem, no search success on iboats

sorry to offend you but if you had given the above history on the first post, instead of "Original factory setup and very few hours on engine however engine had not been run in about a year or 2." i would not have made the statement. primer is replaced the choke it is a solenoid the squirts fuel directly into the intake manifold. the lever on the solenoid, should be directly inline over the body of the solenoid, to be in proper running postion, any other position, it can let excess fuel into the intake. Beige color are running fine. sounds like the black one is not firing completely. leaving unburnt fuel deposits. you say it acts like it is starving for fuel, but it is getting plenty, how can you tell that, i can't tell what is getting thru a carb. you could have a partially clogged pick up in the fuel tank, not allowing enough fuel at high speed.

 

[roscottjr]

Re: WOT problem, no search success on iboats

tashasdaddy,

sorry for any misunderstandings, yes that was an error on my part for not getting the other info in the original post.

I only assume it is getting plenty of fuel because even though it wont go over 3200 rpms in purrs like a kitten at 3200. It doesnt sputter or spit or anything. The boat belongs to my in-laws and they got it from a real close friend. He said he cleaned the tank and everything but then again I ended up replaceing a carb. I didnt think about the pickup in the tank being partially clogged. Would that also cause it to run slightly erratic when in idle?

Robert

 

[roscottjr]

Re: WOT problem, no search success on iboats

sorry to offend you but if you had given the above history on the first post, instead of "Original factory setup and very few hours on engine however engine had not been run in about a year or 2." i would not have made the statement. primer is replaced the choke it is a solenoid the squirts fuel directly into the intake manifold. the lever on the solenoid, should be directly inline over the body of the solenoid, to be in proper running postion, any other position, it can let excess fuel into the intake. Beige color are running fine. sounds like the black one is not firing completely. leaving unburnt fuel deposits. you say it acts like it is starving for fuel, but it is getting plenty, how can you tell that, i can't tell what is getting thru a carb. you could have a partially clogged pick up in the fuel tank, not allowing enough fuel at high speed.

Yes the lever is in the correct position. The one in ours squirts the fuel into the top of the carbs though.

Robert

 

[wilde1j]

Re: WOT problem, no search success on iboats

If it responded to the primer by increased RPM's, it sounds like a fuel delivery problem. Fuel pump, air leak on suction side of pump, clogged filter,pickup restriction, vent problem, etc., etc. No reason "it won't purr like a kitten" with a fuel restriction!

 

[roscottjr]

Re: WOT problem, no search success on iboats

Ok Im not sure how to put this or who to give credit to. I think giving credit to everyone who replied to my thread is in order here.

I dont know what the problem was and had not had a chance to look at it while at the lake. However, we were takeing the boat from the dock to the boat ramp to bring it home when the engine spit and backfired a couple times then jumped to 5600 rpms. It ran purfect all the way to the ramp so instead of loading it and going home we spent a few hours riding around in the boat. We were all excited that whatever the problem was had fixed itself.

I am assumeing it was a piece of trash in a carb, fuel line, or pickup. Somewhere in the fuel delivery there had to be a piece of trash that finally turned loose.

THANKS to everyone for the help.

"There is no place like iBoats"

Robert & family