Wierd Bogging and Temp.

[cobra198]

Recently i have been having a problem with my t maxx 2.5. When i take it out to bash, it doesn't last very long....After about 5 mins of running the engine starts to bog out when i hit the gas. After a minute or so it gets really bad. When i bring it in the engine doesn't sound normal. I dont know how to explain it, but its kinda skips in and out. By now the engine is running really hot. It seems to be overheating, because it wont start again for a few minutes. I dont know what to do. Lean to get rid of the bog, or richen to cool the engine down? Neither seem to work for me. Anybody have any suggestions? Thanks a lot.

By the way i am running blue thunder 20% fuel with a pretty much stock engine.

 

[olds97_lss]

Sounds like your piston and sleeve are shot to me. Time for a rebuild.

Or, you could try to re-seal the carb neck and back plate. But it sounds like the piston/sleeve are worn.

 

[lykan]

It sounds like youe engine is out of tune. Definetaly too lean.

If you are having trouble with it keeping a tune, most likely you have a hidden air leak. It will be confusing, and you won't be able to find the sweet spot. It will either be way too rich, or way too lean.

Check fuel hoses, glow plug, head bolts etc.

You will definetaly need to richen it up.

Here's the theory.
Nitro fuel has the lube in the fuel
Without enough fuel, you don't get enough lube.
Then you get friction, hence the heat.
Both heat and friction will destroy your engine quickly.
Heat will cause things to warp, and not fit right.
Friction will wear down your piston faster.

When you run overly rich, you will loose a bit of power, and it will hesitate when you take off. This is a pain, but won't hurt your engine at all. You may use glowplugs faster.

When you run lean, there is a distinct possiblity that motor damage will result.

When in doubt, err on the side of caution and run rich.

 

[cobra198]

Originally posted by lykan
It sounds like youe engine is out of tune. Definetaly too lean.

If you are having trouble with it keeping a tune, most likely you have a hidden air leak. It will be confusing, and you won't be able to find the sweet spot. It will either be way too rich, or way too lean.

Check fuel hoses, glow plug, head bolts etc.

You will definetaly need to richen it up.

Here's the theory.
Nitro fuel has the lube in the fuel
Without enough fuel, you don't get enough lube.
Then you get friction, hence the heat.
Both heat and friction will destroy your engine quickly.
Heat will cause things to warp, and not fit right.
Friction will wear down your piston faster.

When you run overly rich, you will loose a bit of power, and it will hesitate when you take off. This is a pain, but won't hurt your engine at all. You may use glowplugs faster.

When you run lean, there is a distinct possiblity that motor damage will result.

When in doubt, err on the side of caution and run rich.

You were right about that. I was allready running my engine rich (cause their was a good amount of smoke), but it still wasn't enough. I richened it even more and that seemed to do it. Thanks a lot for the help.