Help diagnose 2 problems please

[surroundsound64]

Seems to me it is electrical related since it only happens with warm engine AND misses badly at speed. This tells me to start looking for electrical components that fail with heat and thus cause a weak spark condition. My first thought is the ballast resistor, if so equiped. Trying connecting all wires to one side of the resistor (does not matter which side) and see if the problem is resolved. If so, then replace the resistor (do not simply bypass permanently).

If problem presists, then suspect the coil next (even though it is relatively new). Then start looking for bad grounds and electrical connections on engine and key switch. Poor electrical connections can get hot, once hot, resistance builds, once resistance builds, electrical current is compromised, blah, blah, blah....

It should be perminately bypassed because he has electronic ignition.

I have had lots of problems with elecronic ignition in my boat, the same problems you had described, but it ended up being the electronic ignition parts were for a different model. It started great, and idled great, but then wouldn't run good at all at higher rpms.

You might want to verify that it is the correct part number.

[jthooker]

Re: Fuel Pump
I would not suggest changing the fuel pump until you’ve checked the fuel pressure.
If the fuel pressure is low then you will need to remove the fuel pump to determine the problem.
Your mechanic should have the proper fuel pressure gauge and fittings that will allow him (you) to check the fuel pressure while the boat is running at various speeds. He should also know what the pressure should be.

[surroundsound64]

Ya, what jt said. Don't change the fuel pump on a whim. They are expensive and sort of a pain in the butt. If there is fuel flowing through the clear line that goes up to the carb you need to replace it. That's the "emergency" line that allows you to see when the main diaphram breaks.

[fatboycowen]

Seems to me it is electrical related since it only happens with warm engine AND misses badly at speed. This tells me to start looking for electrical components that fail with heat and thus cause a weak spark condition. My first thought is the ballast resistor, if so equiped. Trying connecting all wires to one side of the resistor (does not matter which side) and see if the problem is resolved. If so, then replace the resistor (do not simply bypass permanently).

If problem presists, then suspect the coil next (even though it is relatively new). Then start looking for bad grounds and electrical connections on engine and key switch. Poor electrical connections can get hot, once hot, resistance builds, once resistance builds, electrical current is compromised, blah, blah, blah....

I am kind of a newbie and dont know what the ballast resistor is, or where it would be. Anyone have a picture? I will try to describe what i see when i pull the cap off. With the rotor off, there is just the plate with the electronic ignition. This has (2 i think) wires coming from it that both go to the small polls on the coil. Then the rotor fits on, then the cap.

I will work on the boat later today (after work) and try to get some pictures of my setup, so people can spot any problems they see.

Thanks again, you guys rock.

Jon

[fatboycowen]

Seems to me it is electrical related since it only happens with warm engine AND misses badly at speed. This tells me to start looking for electrical components that fail with heat and thus cause a weak spark condition. My first thought is the ballast resistor, if so equiped. Trying connecting all wires to one side of the resistor (does not matter which side) and see if the problem is resolved. If so, then replace the resistor (do not simply bypass permanently).

If problem presists, then suspect the coil next (even though it is relatively new). Then start looking for bad grounds and electrical connections on engine and key switch. Poor electrical connections can get hot, once hot, resistance builds, once resistance builds, electrical current is compromised, blah, blah, blah....

It should be perminately bypassed because he has electronic ignition.

I have had lots of problems with elecronic ignition in my boat, the same problems you had described, but it ended up being the electronic ignition parts were for a different model. It started great, and idled great, but then wouldn't run good at all at higher rpms.

You might want to verify that it is the correct part number.

I will check the part numbers after work as well.

[fatboycowen]

Re: Fuel Pump
I would not suggest changing the fuel pump until you’ve checked the fuel pressure.
If the fuel pressure is low then you will need to remove the fuel pump to determine the problem.
Your mechanic should have the proper fuel pressure gauge and fittings that will allow him (you) to check the fuel pressure while the boat is running at various speeds. He should also know what the pressure should be.

I havnt had my mechanic back since last year, as i like to do things myself as often as possible. Not for money reasons, but because i enjoy learning.

[fatboycowen]

Ya, what jt said. Don't change the fuel pump on a whim. They are expensive and sort of a pain in the butt. If there is fuel flowing through the clear line that goes up to the carb you need to replace it. That's the "emergency" line that allows you to see when the main diaphram breaks.

No fuel in the clear line.

How do i take apart the fuel water seperator to inspect that?

[EchoLodge]

I had a similar problem with my 90 Sport. One time it was a coil. The second time it was the gas anti siphon valve. This is located in a 90 degree elbow that sits on top of your fuel tank. It has a strainer in it and mine was clogged. You can remove it and clean the screen.

[Quinner]

On my 77 SN I had the issue of sputtering etc. over 3k rpm and mine turned out to be the anti-siphon valve also.

[mfloski]

Fuel Pump:
To purchase the gauge to check the fuel pump is about 50 bucks...off skidim.com web site, a new fuel pump is about $80.00...because of this I changed mine on a whim it happened to be a good choice. it is very easy to change out...if your mechanical, should be a no brainer.
Anti-Siphon valve:
Anyone have a pic of this.....what does it connect to?

[Rick]

It still sounds like the ignition module may be wrong and not allowing the advance needed to run faster. The Choke should be wide open when warm If noe you may not be getting the air it needs. The choke on my 66 Barracuda was wired always open. In So Cal it was never cold enough to really need a choke. Also Check that the ciol is a electronic ignition rated coil. My bet however is on the choke and the Ignition module.

[fatboycowen]

It still sounds like the ignition module may be wrong and not allowing the advance needed to run faster. The Choke should be wide open when warm If noe you may not be getting the air it needs. The choke on my 66 Barracuda was wired always open. In So Cal it was never cold enough to really need a choke. Also Check that the ciol is a electronic ignition rated coil. My bet however is on the choke and the Ignition module.

I will see what i can do about the choke. Interesting thought. I will warm it up, and hold that plate open and see if she goes better.

I checked the timing at 600 rpm and adjusted to 6 BTDC as specified. I then brought it up to about 2000, and it was at about 22 BTDC. Then 3000 was at about 30 BTDC, which i have heard is good. None of these things will help my first concern which is no hot start. Without hot starts, i cant really use the boat.

Thanks,

Jon

[fatboycowen]

On my 77 SN I had the issue of sputtering etc. over 3k rpm and mine turned out to be the anti-siphon valve also.

Sweet, i will check that sucker. I like easy fixes, lets hope this is the one!

[EchoLodge]

Anti Siphon Valve

No picture but it is easy to find. Follow the gas line from your fuel pump to the top of your gas tank. It is the 90 degree elbow that goes into the tank.

[fatboycowen]

Update

I checked the Antisiphon and the Tank vent. Then i went looking for the ballast resistor. I think i found it. Is it at the back of the motor, under a black plastic box? Is it white, and about 3 inches long with one wire one each side?? If so, i found it, and it wasnt bypassed. I connected the two wires going into it togather shorting it. Then we started the boat, and it ran like usual.

Thunderstorms were coming, so we ran the boat on the mooring for a while, and found that the 3200 rpm studder still remains. However, we couldnt reproduce the no start condition. We ran the boat for about 15 minutes at varying RPMs, and the boat kept starting fine!

Then, we shut it off, and tried again to start it, and a spark came from the battery area, and everything died!!! We must have blown a fuse of some kind, but we couldnt figure out what.

We waited a while, and the power seemed to come back on. Tried to start again, and another small spark and no power.

Did we do something wrong???

Thanks again for everyones help.

Jon