Sn2001 gremlins

2nd thread of my ccf career, I'm still struggling with this boat, I love having the thing and being on the water but geeze it's becoming frustrating.

So what I'm dealing with now is basically the boat won't run IN GEAR above 1200 or so rpm. It seems like it's bogging down and will occasionally die if I don't return to neutral quick enough. It Started out great today, I've got the idle issue almost completely dialed in and correct (http://www.correctcraftfan.com/forum/forum_posts.asp?TID=39332&title=83-351-stalls-in-idle-gear). We got on the water this evening and pulled through the long no wake zone at my preferred ramp, we then took off and ran great for 3-5 minutes and all on its own, it was like I pulled the throttle down toward neutral, slowing the boat and dropping the rpm.

Now I had A similar episode Friday, btwn then and tonight I put in a new fuel pump and filter. And changed oil, probably out of paranoia that the diaphragm in the pump had failed and leaked gas into the oil.

The boat is currently running like a champ in idle gear and seemingly purrs throughout the rpm range while not in gear.

I read that a hose or tube in the fuel tank can become clogged and should also be cleaned. Can anyone help me with info on this???

Are there any other things I should check or look at?

Thanks

8122pbrainard wrote: Trevor, On the top of the tank where the fuel line attaches is the anti siphon valve. It looks like a hose barb fitting. Remove it and see if it's clear.

Thanks for the info. I'll be working on that first thing Thursday.

Tfreeman wrote: I read that a hose or tube in the fuel tank can become clogged and should also be cleaned. Can anyone help me with info on this??? Thanks

The tube that picks up the fuel out of the tank. Your problem sounds really similar to what I experienced with mine, even worse probably.
I pulled out that tube (you can do that through the vents on the back, no need to pull the tank out) and cleaned it with carb cleaner, let it soak, gently hit it. There's a filter in there, in my case the tube got clogged with dirt, hairs, even a dead bug.
Easy fix that worked wonders!

You could:

Diagnose this as a fuel starvation problem first. Take the motorbox and flame arrestor off. Go do your normal thing and when it starts bogging down look down the carb to see if you're getting gas when throttling.

If you are in fact not getting fuel out the boosters start working backwards to the tank incorporating each component in the fuel system one by one. Run off a gas can starting at the pump, then after the filter/separator, then line to tank, Certainly starting with a clean pick up tube and anti siphon valve is recommended. That's good maintenance.

Hollywood wrote: You could: Diagnose this as a fuel starvation problem first. Take the motorbox and flame arrestor off. Go do your normal thing and when it starts bogging down look down the carb to see if you're getting gas when throttling. If you are in fact not getting fuel out the boosters start working backwards to the tank incorporating each component in the fuel system one by one. Run off a gas can starting at the pump, then after the filter/separator, then line to tank, Certainly starting with a clean pick up tube and anti siphon valve is recommended. That's good maintenance.

I forgot to mention that as well. So yesterday evening while still on the water I removed the flame arrestor and had the wife give some throttle. According to my best guess, as I have nothing to compare it to, the spray from the accelerator pump looks like it changed from a V shaped spray (like when the motor isn't running) to more of a light mist. In my opinion it looked like a lack of fuel, but I am not completely sure with my lack of experience.

I almost believe I can pull the anti syphon tube and clean it and head to the water for a test, of course I would bring a can to test if it's still acting up, I think that would end up being more efficient then 2 separate trips for potentially the same thing.

Fuel delivery is definitely going to look different running vs not running.

Next time it bogs down on you shut it off and pump the throttle and again compare stream.

Hollwood is Plan B

Check the inlet screen at the carb first. I've experienced several plugged anti siphons but they would always fill the fuel bowl during low rpm operation- it would only run out of gas at sustained higher throttle (flow can't keep up with demand). Even significantly clogged valves acted this way- they really only catch very large particles.

The fuel inlet screen at the carb is very fine though- and if plugged can significantly limit filling of the bowls to the point where any throttle input results in a stall. So I'd start there.

I also would not rule out ignition- what do you have for an ignition set up? Info on dizzy and internals to wires, cool, plugs and wires please.

TRBenj wrote: Check the inlet screen at the carb first. I've experienced several plugged anti siphons but they would always fill the fuel bowl during low rpm operation- it would only run out of gas at sustained higher throttle (flow can't keep up with demand). Even significantly clogged valves acted this way- they really only catch very large particles. The fuel inlet screen at the carb is very fine though- and if plugged can significantly limit filling of the bowls to the point where any throttle input results in a stall. So I'd start there. I also would not rule out ignition- what do you have for an ignition set up? Info on dizzy and internals to wires, cool, plugs and wires please.

The previous owner did some sort of electric ignition. I've got no clue on the specifics he put in, but the cap has clean contacts.

I had some carb issues, that resulted in me working through a rebuild, vacuum leak, adjustment etc to solve a poor idle, but the boat ran descent throughout that time frame above idle speeds, I guess at the point that the mixtures over came the vacuum leak, anyway, I seemingly had that squared away and then this started.

I will put the inlet screen on the Check list.

Well, I have no real update, I did not make it to the water today for a test, I will head out for that tomorrow first thing. Today I checked the tank vent and anti syphon tube, found nothing remarkable on either, cleaned them for good measure. I saw a little debris in the tank so I went ahead and pulled it, cleaned that also. I ran a temporary fuel line from the strainer back to use for checking purposes. I checked the carb screen. It appeared clean, but cleaned it anyway. While in that area, the fuel hose btwn the pump and carb had a couple of slight kinks in it. I know it's a replacement hose, not sure if it's factory length, style, size, or routed correctly. Either way, I pulled it out and routed in a way to avoid the kinks. Also while the supply line was unhooked, I blew it out with my air compressor.

I did notice a little resistance and then has erupted out of the other end and stopped when it met the Bimini top. I was not able to locate a clump of debris or anything to confirm it was clogged, but I am certain the fuel line is clear in both directions.

I guess tomorrow the only other thing that could starve the motor would be if I over adjusted the float in the carb. Other than that I guess I'll have to get onboard with the possibility that the problem is not fuel related.

Hollywood wrote: Tfreeman wrote: While in that area, the fuel hose btwn the pump and carb had a couple of slight kinks in it. I know it's a replacement hose, not sure if it's factory length, style, size, or routed correctly. This sounds like a potential hazard, take a closer look at that hose. FEDERAL LAW: 183.558 Hoses and connections. (a) Each hose used between the fuel pump and the carburetor must be “USCG Type A1” hose. http://uscgboating.org/regulations/assets/builders-handbook/FUELSYSTEM1.pdf

It is a coastguard approved hose, manufacture date of 2004 or 2008 can't remember, that's how I know it is a replacement. But the rest holds true, idk if he slapped in some hose or if it is a direct replacement

Have we ruled out a weak fuel pump yet? Have you measured pressure?

Here is a video of my vacuum guage from today, if someone can guess better than I can.

https://youtu.be/rBmZzlEdcUY

Trevor,
With the changes you are getting in the timing, it does sound like you may have a issue with the distributor. If you haven't checked, make sure the advance mechanism if free to move. Pull the point plate and lube the flyweights. Check the springs to make sure they aren't broken. Don't worry about them being loose. In the retarded timing position, they are loose.

Inside the distributor, I have found two attached springs that are activated(I guess) by the fly weights, but they are not the same springs. I am assuming this is incorrect.

Also in the caked on grease in the bottom of the housing I found pieces of a spring that are thin like one of the installed springs. I'm guessing it was broken and replaced with a different spring in the past.