engine stalling.

[Trickey]

Hi all in haveing problems with my inboard f1 tunnel. its running a 11cc k&b and starts and idles fine but when i send it out on the lake it accelarets for maby 20 meters and dies. Ive tryed adjusting the needle but it didnt help also changed plugs. Heres the bit that i cant work out, i can test run holding the boat in the water and it runs fine but send it on its way and it dies! >

One thing i was thinking was can carb icing the air temp with wind chill was only 3 to 5 d celsius,

Im a newbe so any ideas would be great.

 

[Grimracer]

Trickey

Sounds like you are not geting enought fuel to the motor. this could be in any fourm...to small a needle, bad bearings. and many others.. first make sure that the needle is way out.. it should at least run there but use lots of fuel and go slow.

Grim

 

[paul heuston]

check for water getting to the carbi as our motors don't like water for some reason.....

if it helps try to get to a pond with a few regular boaters and ask them to help as a boater that can look at your boat would normally get the problem straight away...

paul

 

[Trickey]

Thanks guys for your ideas ;D I tryed adjusting the needle out mabey1.5 turns but no change, is 1.5 enough??I are in the process of stripping the fuel suystem one thing that i noticed was some burnt oil/fuel in the pressure line from the pipe to the tank,it wasent blocked but could this be part of the problem??

How about carb icing i know this can be a problem on older cars with carbs the temp was only justabove freezing.

 

[GTR]

Hi Trickey

Is that the needle turned out 1.5turns from closed? If so it's no where far enough out. Probably should be between 2.5 & 4turns depending on howmuch Nitro you're running.

Will your motor pull max RPM at the bank with the prop it has on? Do you surface it at all or just hold the boat in the water? If it will pull max RPM while stationary your prop is way to small.

Just a few more ideas.

GT ;D

 

[Trickey]

Gt Sorry I should have been more specific i ment that i took the needle out a further 1.5 turns probberly about 5.5 turns in total. The moter will run max rpm will holding it in the water with the prop surfacing and looses rpm when buried, What i cant work out is why after test running in the water and running fine why does it die when i send it out on the lake. :'(

 

[Trickey]

Gt Sorry I should have been more specific i ment that i took the needle out a further 1.5 turns probberly about 5.5 turns in total. The moter will run max rpm will holding it in the water with the prop surfacing and looses rpm when buried, What i cant work out is why after test running in the water and running fine why does it die when i send it out on the lake. :'(

Im only running 10% nitro and i should say that the boat has runn very well in the past!!

thanks Trickey

 

[GTR]

Hi Trickey,

It's definately lean. That is so far out on the needle it might fall out. LOL No, seriously you must have an air leak somewhere, fuel lines, crankcase, blocked needle valve. On that amount of Nitro I'd expect it to run around 3 turns out at the most. Look for something wron in the fuel system.

Without being there it's trickey (no pun intended) to diagnose. Has to be fuel system, somewhere.

Dumb idea, have you tried a new plug?

GT 8)

 

[TimD]

What I would do is put in a new plug - then try and run it.

If the plug looks grey around the edges of the element then the motor bearings are kaput! if the element looks dull then it's lean.

The other possibility is that the engine is sucking water in from somewhere - either thru the carb or the head. Engines that have a head button that is surrounded by a cooling sleeve are notorious for this....

Also, can you see bubbles in the fuel line while it's running on the shore? sure sign of a split or holed fuel line or tank.

 

[Trickey]

Hi guys thanks for your ideas.I have decided to replace all the fuel lines so that might rule out one possabilty,and this weekend i am going out with some experienced boaters so they can proberly sort it for me.

Thanks again Trickey

 

[Altimat]

Maybe your prop is too big??? What is the water temperature?? That ice cold water could really help put the fire out quick too especially if its overpropped.

 

[Tony Jacuzzi]

when the boat is on shore and running and you pull the trigger it should NOT RPM right away. It should hesitate a little bit as it clears itself out. Generally if too rich it will putt around but wont stall in the first 20 feet. Put your hand at the stinger outlet it should be getting some fuel/oil misted on it. Make sure that there is a little bit of a lag on the throttle and once you get it running laps then lean on it a tad at a time. If the needle going in and out doesnt affect the motor start looking for air leaks in fuel lines, tanks etc... Tony J

 

[Trickey]

Hi all problem solved!! the boat was running a header tank which had a air leak it apears i bypased it and problem solved. Just some fine tuning needed now.

Thanks everyone for your invaluable advice

Trickey ;D

 

[EatMyShortsRacing]

Those air leaks can be tricky things.... they have a habbit of leaning out one engine on a Twin 90 Rigger and stopping it from completing a race... wonder what boat that may have been..

EMS Racing just one leaky piece of silicon!!!