GT40 probs

I will try and make it brief:
Our cover does not keep out the rain. The plug was not pulled. The bilge filled up with water about half way up the oil pan. I drained the water, and put the boat in the water. It ran really rough with small backfiring. I shut it down and pulled it in the garage.
1. Cleaned Dist Cap and rotor.
2. Cleaned strainer (it was really full)
3. Tried to start it on the hose. Turned over, no starty
4. Pulled fuel filter it was pretty dirty.
5. Pulled spark arrestor it was kind of dirty.
6. Checked that both fuel pumps came on

I am going to se marine tomorrow to get fuel filter, Dist cap & rotor. Next I will check for a big blue spark on the ignition side. I perused the diagnosis guide so it has lots of tips.

My concern is that that I have some moisture in a relay or something. Any tips? Where do I start?

seacamper wrote: Also, I have the connectors pulled to the low and hi pressure pumps and the fuel canister spun back on the FCC. Can I turn the engine over safely to check for spark? Tom

In theory, yes.

In my previous experience with misbehaving GT-40's, I'd say you're on the right track with the tune up parts. Those are low hanging fruit as far as cost goes and are always good peace of mind to know they're new.

Might as well throw a new FCC hose in there while you're messing with the canister. They can cause the "running really rough and backfire"

We had the same issues last year after a new FCC hose, hard starting and all around running rough, which turned out to be a coil. If the others (tune-up/cheap parts) don't solve the problem then I'd look to the coil.

^^Agree on the relays.

In line Spark Testers come in handy for testing spark. You can leave your spark plugs in place so you don't have to worry about fuel getting everywhere.

If I had to guess on the FCC shrader valve it might be to bleed the system. Or to measure fuel pressure at different points.

The Schrader valve on a fuel rail is indeed to check fuel pressure and you can use it to bleed pressure to change fuel filters. At least on an auto. I would have to assume the same thing on a boat.

I don't quite see any electrical going into or out of that but it actually looks more like a spin on fuel filter/water separator. If you're saying it has power I'm obviously wrong.

Hey Larry,
From my meager research, and perusal of the manuals, I would say that is the Low Pressure pump. It looks like it may be situated a bit differently because I am guessing that it is near the starboard forward motor mount? Mine is near the port fwd part of the engine, and right next to its big brother, the big canister called the filter/water separator or FCC. The Low Pressure pump should deliver about 6Lbs pressure, and it also has a volume test over a period of time. Look in the reference section for your friend and get him the GT40 manual. There is a good description there. My thinking on his problem would be that the low pressure pump, which is a sealed unit, should be replaced. If it is popping breakers, I would just replace it. I think less than $150. Call Zach at N3, or if you are in NC you might call Skidim to get the parts faster. Also order the two relays at the back of the engine next to the CB's. They are about $15 and are the same unit. One runs the fuel system and the other the EEC. It seems they are also a weak point in the system, and it does not hurt to have them wrapped up in the glove box just in case. If I am wrong, I am sure I will be gently corrected!
Tom

We have a manual for the GT-40, in the reference section.
http://www.correctcraftfan.com/Downloads/Pro_BOss_GT-40_Service_Manual.pdf

I personally think your best value is a pre-printed manual from skidim. I own the one at the top, it comes in a nice three ring binder and it's cleanly printed. You'd be hard pressed to print them yourself for less, unless you worked at Kinkos or something.

There's two that would cover the GT-40, 3rd and 4th from the top:
http://www.skidim.com/searchprods.asp?searchstring=manual&pagenumber=1&val=0

Sorry Larry, I had taken a look at your thread, but I had no idea on what's in the pic.

lewy2001 wrote: Seacamper here it is:- "Also check the output of low pressure pump as mentioned previously. This is achieved by disconnecting the high pressure pump electrical connections at FCC. Remove fuel hose from low pressure pump to FCC and place it in a container. Install the jumper to STO terminal it should pump about a US Quart in around 15-20 seconds." Larry that looks to be the same low pressure pump that PCM used on both the GT40 and the Excal. They are a Carter fuel pump.

Thanks Mark,
Just what I was looking for. So I did that and my gas looks like lemonaid. How did that happen? I have poured out about a gallon, and its still lemonaid. Milky yellow. Could it be? Bad fuel all along? Sigh. I probably have about 8 gallons to dump. Where do you get rid of 8 gallons of gas?
(I think we all know the answer to that)
Tom

seacamper wrote: Sigh. I probably have about 8 gallons to dump. Where do you get rid of 8 gallons of gas? (I think we all know the answer to that) Tom

-Divide gas equally and place into 4 large garbage bags.
-Attach M-80 or quarter stick of dynamite to 3'x3' piece of card board, repeat 4 times
-Place garbage bag on top of cardboard
-Detonate remotely (minimum 100')

emccallum wrote: Did you have ethanol blend fuel in it? Sounds like you need to dump all the bad fuel, drain lines, change filters, and say a little prayer that that was the problem. As for what to do with the old fuel....it can only go two places; The sky or back to where we got it!

My kids voted for the dynamite, but my wife overruled it. I guess it goes back to mommy nature.

I would get as much out by hand through the fill tube then dilute what is left with a fresh gallon or two, then pump that out.

I have always just evaporated bad gas in an oil drain pan. Depending on the amount, it can take some time and you will end up with a gooey mess.

Did you check the FCC hose and filter? Just saying, you're going to a lot of work and $ for a very common $1 part and a 15 min fix. Knock out the easy/cheap options first. Outside of that I'll shut up.

storm34 wrote: Did you check the FCC hose and filter? Just saying, you're going to a lot of work and $ for a very common $1 part and a 15 min fix. Knock out the easy/cheap options first. Outside of that I'll shut up.

Hey Chris,
Yes, new filter and hose go in tomorrow. I will also have 2 relays on standby. I also needed to get to the anti siphon valves to rule out that simple problem.
Tom