Big Red 28

[deputybill705]

Good morning everyone. I have a Big Red 28 on my MGT 4.6. The motor has been sealed and has 1 gallon or a little more through it. The problem I am having is the engine will not accelerate past have throttle when I try to lean the motor pass factory settings. The motor idles fine. I can't get the temp past 180F. I have never had a motor do this. I took the motor apart and cleaned and sealed it. Put a new glow plug and fuel line on it with no change. Any help would be appreciated.

 

[ninnon]

Are you sure the carb is opening fully?- check your servo's. Also, have you tried checking you whole exhaust and fuel system for an air leak?- most tuning problems I've had have been fixed by fixing and air leak.

 

[Rolex]

When the engine is properly warmed up, does it launch off the line without stuttering when you hit full trigger? If not, it's a LSN adjustment.
When that's been corrected you go on to the HSN for WOT.
Not getting over that low temp could be a combination of both needles.

 

[hotrodrob]

Right!...and if it had an air leak you would be having the opposite problem

 

[Rolex]

Thanks for your support, hotdogbob.

 

[deputybill705]

The carb does open fully. The truck launches great off the line but bogs down about 2 ft out or so. The trick has a brand new fuel tank and fuel lines on it. I have not checked the fuel system or exhaust for leaks but I will. I will update everyone with what I find. Thanks for all your help.

 

[hamz9561]

Check your throttle linkage for binding and full travel.

 

[Rolex]

https://www.rcnitrotalk.com/misc/tuning-flowchart.pdf

 

[deputybill705]

Update on the Big Red. I took the motor out of the MGT and put it in the LST2. The motor does the same thing. It bogs down if I try to lean it any from factory. I checked the MGT tank for leaks. The tank checked good. I'm thinking the carb could be bad. Any suggestions?