doctoreagle

How badly does bumps/jumps affect the engines??

My boat went off a curb at full throttle and after it landed it quit running, and didn't run good for the rest of the time out.
I will play with it again tomorrow to readjust the needle valve, but could I have damaged something??

pro27

It depends on what it landed on or in. Did the engine itself hit anything? Did you break the prop?

We need more details.

doctoreagle

It laned on flat ground(lightly snow covered pavment). The engine kept running for a few seconds after, then studered(sp?) and finally quit. After that I tried to start it at half throttle and it ran until I opened the throttle more, then it studered and quit. I adjusted the needle valve a bit and it made things alittle better, but it would still quit after a few minutes and I couldn't get it to run at full throttle very well. Just kept dying out when I applied more stick.

The landing wasen't any harder than most it takes from the looks of it, just a small curb. This craft does take a beating when being used, it's never on the ground long before something makes it get airborne, lol.

Slayer-RCU

It could be a number of factors such as:

1. Air in the fuel lines (loose or ruptured),
2. Fuel tank pickup,
3. Carb knocked loose
4. Lack of fuel pressure for exaust

I was suffering a similar problem and it turned out to be the Clunk in the fuel tank..it was bouncing out of the fuel and sucking air....hope this helps.

Slayer

pro27

The four main culprits reveiled again......
I would check all these things. It doesn't take much to create a pin hole or tear in a fuel line or pressure line, and they are not always easy to spot.
#3 also deserves a good look, as ell as all the bolts and screws on the engine. Again, it won't take much to create an air leak on these engines that will cause erratic running.

doctoreagle

Well I replaced all the fuel lines and checked the tank, thats all good. The carb is screwed down and doesn't appear to be loose. BUt it just won't run right. It will start and idle, run it to full throttle and it dies after a minute or so. If I cut the throttle back it will recover and stay running. But as soon as I go back to full throttle it dies again.

I think I am going to have to take it apart and try to rebuild it.

Mr Cajun Gator

before you rebuild, try 2 things, one at a time.
1. Richen the needle
2. Replace the glow plug.
Also, check that the fitting on the exhaust that your pressure line is connected to, and make sure that it is open.
Sounds like what is happening is that the engine is not getting a good flow of fuel.

pro27

Not knowing how well you know the tuned sound of a nitro engine, but at full throttle, when it quits, does it quit abruptly, ( like now) or does it fall ooff innn rrrpppmmmm'sssssss aaaannnnnnnnndddddddddddddd tttttthhhhhhheeeeeeeennnnnnnnnnnnnnnnnnnnn
quit?

Could the spray bar have been jarred loose, and moved position causing it to be too lean or become overly rrriiiiccchhhh when at full throttle?

This may seem elementry, but didn't know how else to put it.....

TERBObob

My Feedback: (21)

Gotta agree with the others ...
I would first change the pressure line that goes from the muffler/tuned pipe to the fuel cell . Then , also check your fuel clunk ... make sure that its still connected to the line inside .
Then , as the others have stated ...
Like PROP said , sounds like a fuel pressure problem .

Model_Mann

my dad 'll be home this saturday ill ask him if he calls tonight, mabe he would know, i mean the man runs his own small engine business, and will fix any thing from my model engines, to anthing the size of a bob-cat and smaller, (hey pro, hint hint wink wink nudge nudge)

doctoreagle

Well I took the thing apart and couldn't see anything visibly wrong with it, everything looks good. I am going to try larger fuel lines to see if that changes anything.

It doesn't die right away, you can tell when it does and cut the throttle back and let it recover.
I don't see any type of spray bar, unless I need to take the crank out to find it, which I didn't do.

TERBObob

My Feedback: (21)

( inside the throttle - the bar that goes across that lets the little squirt of nitro into the throttle neck venturi . Where the needle goes into )

doctoreagle

Well I don't know what is was but she is running fine again. I took apart and reassembled the engine and repalced all the fuel lines.
Dunno.

But the good news is its running again.

Mr Cajun Gator

warmer weather.... pin hole in the fuel line....bad fuel line connection......engine was to lean. If it happens again check these things before you go to breaking down the engine. But try only one at a time.

pro27

Sometimes them gremlins figure they had enough fun and move on, leaving you to scratch your head and wonder........