Scale won't stay running

[Don Riek]

Guys,I like the strut leak as the possible problem, however I just looked at the strut entry through the hull and it is virtually sealed with just a very small hole at the trailing edge of the strut. I will seal this off completely and try again.

I had, along the line, thought about water intrusion but could not pinpoint the entry point. The sponge idea is a very clever one and I will try that also because if it works, I can track down the cause from there. Also might have to make the sponge standard equipment!

I have pretty much ruled out overheating with the drop in Nitro %, also there is no indication of lean condition. Water exit is through the hull next to the motor and has not been changed.

Thanks for all of the ideas so far and yes, I will be letting everyone know how this turns out.

What about the exhaust? How does it exit the hull?

Doug,

Exhaust exits directly through an opening in the cowling via an extension tube on the pipe's stinger. The tube sticks out past the opening just a bit.

 

[Bill Gibson]

I would replace all lines fuel and water. check your water nipples on your motor. check o ring on motor head. check lines in side of fuel tank. Rudder pickup does the boat pee when running. and is uour preasure line clogged on the pipe. just some things I would check then check your bearings and drive line for binding. but it really sounds like there may be a water leak some wear maybe at the srtut that is making a mist in the hull choking the motor. This happened to me when the silicone came undone on my circus. it would run for a lap and quick. once i fixed the silicone it ran great. go figure

Already replaced all lines, filter, rebuilt tanks, pressure checked all, all lines free and clear, nothing clogged. Bearings were replaced along the line, no apparent binding (seems like this would be a problem with or without cowling) I will check the misting thing, although I can't understand how water would get all the way to the front with the boat running 50+ mph. This is worth a second look. Thank you!

Id think you could see water coming from the strut ,ive had this happen and it is tough to pinpoint. Also had a blocked fitting on the pipe crap built up and closed it off. I had a 82u55 PT hull that would not run with the cowl on,found only a Macs pipe would work. It would run like heck for a couple laps then lay down and die. Prop it down a bit if you have not piched the sleeve in a while. Hey if it dies after a couple laps bring it to Atlanta maybe i can beat you for a change.............Mike PS i hope you get her fixed

Very funny Mike! Right now everybody is beating me! I did double check the pressure fitting and have pretty much ruled out motor problems since the "backup" motor I put in it (Perry Walters') had the same result.

Brian said check for water leak at strut, good idea. Run the boat with out cowl and look for water spray comming out of the strut cut out.. We had a sport 40 do that and the water sprayed inside the cowl right up to the motor with the cowl on. Maybe you could add a floor drain at the back too. Try the old sponge on the floor under the carb trick too.

PHIL T

Phil that was the problem i had with my sport 40 till you made me aware of that.....3 or 4 laps and she'd go dead in the water....it didnt take much of a leak for that to happen either!

 

[Don Riek]

OK, I am going to concentrate on the water intrusion theory. In sealing around the strut I more closely examined an old patch on the bottom alongside the sponson. While this patch had seemed solid when I looked at it along the way, closer checking revealed that it could flex and open up a slight crack that potentially could act as a water pickup. I have done a more thorough patch, so we'll see.

Oh yeah, while working on boats with SHARP turn fins, it would probably be smart to cover the fin somehow. I am now missing a nice chunk of my elbow due to my negligence!

 

[FloridaScaleBoater]

Don, give me a call

772-834-7554

 

[Norm Doerr]

Cracks in the cowl, Cowl moving around.. Cowl.. something with the cowl..

Throw the cowl in the bathtub push it under the water look for cracks and voids.

 

[Don Riek]

Looks like I finally have gotten to the "bottom" of this, so to speak. After carefully sealing at the strut and the old patch, I just ran 8+ laps with no issues until I hit something (gator?, turtle?) which put a nice nick in the rudder and broke the breakaway pin. Since I had taken no spare parts with me, I was done. I'm pretty sure the problem is now solved, though.

Thanks to all who offered suggestions. You definitely got me going in the correct direction.

:lol: :lol: :lol: :lol: :lol:

 

[Bill Gibson]

Looks like I finally have gotten to the "bottom" of this, so to speak. After carefully sealing at the strut and the old patch, I just ran 8+ laps with no issues until I hit something (gator?, turtle?) which put a nice nick in the rudder and broke the breakaway pin. Since I had taken no spare parts with me, I was done. I'm pretty sure the problem is now solved, though.Thanks to all who offered suggestions. You definitely got me going in the correct direction.

:lol: :lol: :lol: :lol: :lol:

Don, i know all about that turn fin deal!!! seems like every time i build a stand for my boats i build it in such a way that EVERY time i go to pick up the boat by the stand its EXACTLY where the turn fin is and OUCH!! guess ill never learn! Glad your gettin the bugs worked out on your scale boat, and WATCH OUT FOR THEM TURTLES!! Bill