troubleshoot a high end power lose

Haven't made it back to the boat yet...

Based on the other posts I'm going to check the fuel pick up in the tank for blockage first thing.

Hope to get down there this weekend - but I've been saying that for two weekends now...
 
I had the same problem on my 240 SRV, check valve at the tank was full of muck, pulled it, cleaned it, no more problem.
 
Opened up the fuel tank hatch. Pulled the pickup tube. The screen was as clean as the day it was made. Checked the valve, it was clean and functioning. Reinstalled eveything. I'll try replacing the fuel pump next.
 
Spark!!! Forget the fuel until you verify the spark. You said your wires were old. Check your distributor and make sure the points,weights and springs are good and moving freely. You need it changed anyway as you said they were old. I would tackle this before you go digging into the fuel system. If its starving for fuel she would heat up...
 
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Alot of talk about the coil. It is one of the easiest thing to check. get a couple of feet of wire. Attach one end to the negative terminal of the coil. disconnect the coil wire from the top of the distributor cap. turn the ignition to on. hold the coil wire about 1/4 inch away from your carb stud or any other good ground. then momentarily touch the wire you connected at the coil to a good ground or the neg on the battery. you should see a healthy spark. this trick is more helpful at diagnosing a bad wire in the distributor. that is often the reason people often replace a perfectly good coil.

pretty good trick some might find useful
 
I put on new wires a while back, no difference. Checked the timing which was at 14 so I reset to 9 BTDC. Plugs remain a light gray with no fouling. Ran at night with the hatch open and no dancing light show.

So took the marine mechanic out for a spin. His take was the pump. It looks to be OEM and she has over 1400 hours so a fressh one couldn't hurt.

We'll see...
 
Have you taken the top off the carb. It is possible that you have a small amount of water or dirt in the bowl. when you try to get her up on a plane, the angle of the boat changes and the crap pools to the back of the bowl. pop the screws off and look. 10 minute job and you will know right away! seen it more than once!
Phil
 
I had the same exact problem. I changed everything mentioned in this post and beyond. I ended up finding out I had the wrong drive ratio. Also a few major issues (heads needed to be redone and collapsed lifter). But even after that work was done, it STILL wouldnt go beyond 3400 RPM. Once they changed the upper and lower drive, problem solved. I now get her up to 4200 RPM with no issues. Check your ratio on the upper and lower drive.
 
Riptide III said:
Have you taken the top off the carb. It is possible that you have a small amount of water or dirt in the bowl. when you try to get her up on a plane, the angle of the boat changes and the crap pools to the back of the bowl. pop the screws off and look. 10 minute job and you will know right away! seen it more than once!
Phil
Click to expand...

Hmmmm...Thats something I hadn't thought about. My filters have all been clean so far but I guess some could have found its way through and accumulated ver time? If the fuel pump doesn't fix it I'll look at that. The problem started out subtle but now the motor quits when trying to get up on plane.

DeBlasi - she ran out fine in years past. This is a new problem that has crept up.
 
Riptide III said:
Alot of talk about the coil. It is one of the easiest thing to check. get a couple of feet of wire. Attach one end to the negative terminal of the coil. disconnect the coil wire from the top of the distributor cap. turn the ignition to on. hold the coil wire about 1/4 inch away from your carb stud or any other good ground. then momentarily touch the wire you connected at the coil to a good ground or the neg on the battery. you should see a healthy spark. this trick is more helpful at diagnosing a bad wire in the distributor. that is often the reason people often replace a perfectly good coil.

pretty good trick some might find useful
Click to expand...

Ok. I'm new at this. You want me to climb into the bilge and produce a high intensity spark on the carb? Ok, I understand. I'll be right back.
 
I had a 1974 Dodge Challenger. I was working with the coil. Had the coil wire in my right hand and a wrench in my left hand resting close to the fender. The coil hit me via a bad wire in my right hand and knocked the wrench out of my left hand. They can pack quite a punch. I was about 18 at the time.
 
:smt021been there done that, and lived to tell the near death test:smt101,USE a tester or timing light to test coil/pac:thumbsup:
kybishop said:
I had a 1974 Dodge Challenger. I was working with the coil. Had the coil wire in my right hand and a wrench in my left hand resting close to the fender. The coil hit me via a bad wire in my right hand and knocked the wrench out of my left hand. They can pack quite a punch. I was about 18 at the time.
Click to expand...
 
An update and back to the thread topic. My brother (KRB64) took it out with the local marine mechanic. Having gone through pretty much everything mentioned and likely candidates to the cause, he suspects it to be the fuel pump. He was going to change that out for us. It was about two weeks ago that they took it out and we have not had a chance to get back down to the lake to check. He is a very busy man and highly sought after but he usually gets to those things in a week or so. Thanks for everyones input and we will update you on the results of the fuel pump soon as we get a hold of the mechanic.
 
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Hampton said:
Ok. I'm new at this. You want me to climb into the bilge and produce a high intensity spark on the carb? Ok, I understand. I'll be right back.
Click to expand...

Youre a real funny guy John! I guess I took for granted that the individual is smart enough to vent the bildge and has working olfactory glands.
Seriously though, I would have eliminated the sediment in the carb theory prior to spending money on a pump ect.
 
Haven't blown myself up yet...

Wouldn't the sediment have to come through the pickup screen, fuel/water filter and the carb filter first? All have proven clean so far. Unless it was varnish left over from evaporation maybe?
 
You Would be surprised at what will magically appear in the bowl of a carb despite all the filters. especially if the boat has been layed up for a while. could even be water in the bottom of the bowl from condensation. When the boat engle changes the engine will begin to injest it. I had a boat that ran great till the deck angle changed. the engines would begin to stutter and it would not get up on a plane. Turned out to be water in the carbs.
 
Riptide III said:
... Turned out to be water in the carbs.
Click to expand...

Well that is one of the possabilities we discussed. As stated earlier the mechanic has rebuilt many carbs this season due to ethanol sitting and seperating. After the filter and pickup proved clean he started leaning towards the fuel pump.

My brother talked to him the other day and the thing is still on back order...
 
I know how you feel. Been having the exact same problem. Just tried run the boat today and made it 300 yds and nothing.... Finally got it home and started trouble shooting. I removed my carb cover and tried to start it. No fuel was coming out as I was cranking, so I am now searching for a fuel pump. As I said, my troubles were exactly like yours. Started kinda sputtering, few days later it was hard to get up on plane but then sputted back down, then nothing.... I had replaced the fuel filter, new gas everything. Just kept getting worst each time I went out. Good Luck.
 
My boat is getting up to about 4200 and then surging. I haven't figured it out yet but running in the ocean you don't have the opertunity to run wot too often so it hasn't been too much of a problem, I posted the process, I did almost everything. I have not changed the fuel pump yet. The point is there is a post in the faqs on Iboats about testing the boat side of the fuel system on an I/O which made a lot of sense. In short it says that under load that part of the fuel system can suck air causing the boat to crap out. It will not show up as a fuel leak as the part of the fuel system between the tank and the pump should not ever be under pressure but will be subject to vacume while under load and if there is a leak air will mix with gas causing a lean condition. They tell you how to check the system in the post. Good luck!
 
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