kbailey45

My Feedback: (41)

I just aquired a first generation TMaxx and a Ruslter with pro 15's in them. I bought them because they were cheap and I need something to destroy, i have my Jato for speed. On the Tmaxx the engine runs great but seems to want to die when I stop really fast or after long full throttle runs. My first thought was the linkage but that checked out ok. Temps are good, new plug, idles good at first, performs well and lsn and hsn are good. After this happens I have to Prime the engine to get fuel back to it. It has new fuel lines and the tank seems to be fine. I got a gallon of Trinity 25% with the trucks and am using it instead of my 30% I use in my Jato. The price on the jug is $26.99. That seems low to me like it may be old fuel. It doesn't have that "kick" in the smell like new fuel. Could this be my problem? I just finished breaking down the carb and cleaning it. It was dirty but it seems if that was the problem it would run like crap always. Like I said the motor runs great and actually has a little more power than I thought it would but wants to die after a few minutes. Once it dies and you get fuel back to the carb you are good for a few more minutes. The fuel isn't foaming. I have cleaned the carb and will try my fuel in tomorrow to see if anything is different. Also it had a blue pipe on it like a resonator but no writing on it. I also have the stock pipe so I put it back on thinking it may have something to do with it. If I can get the ruslter going I can sell it and have maybe $30 in this truck. It is actually in really good shape and I am having good luck finding parts. I would love to get it right so i can have a truck to where I can say "Hey look a giant 4 foot deep mudhole, let's see if I can make it through it" lol. Any suggestions?

8MILLSNIPER007

Your pipe has nothing to do with the issue, it could be bad fuel, but normally bad fuel will also give you issues like hard starting. To me it sounds like as soon as the engine comes up close to running temp it is losing its pinch (compression). You did say that your temps are good, but what are those temps?  Traxxas engines love to run at high temps like 280. 

proanti1

My Feedback: (2)

Pro 15s run hot, they run even hotter with a tuned pipe. How is the compression when the engine warms up?

hobbyshophand

I would also agree that once your engine reaches operating temperature, the sleeve expands ever so slightly that you will loose compression and you motor will cut out. A pinch for your engine should solve this problem.

kbailey45

My Feedback: (41)

I am running around 275. I had two 15's and one had a good sleeve and piston so I just made one good motor. I bought an OS 18 and put on the tmaxx so this motor is now on the nitro sport. I had it running great but now its going crazy again may just trash it.

8MILLSNIPER007

You very well may have a leak in the engine somewhere- on that engine the front bearing is a great place for air to leak in and also if it has the pull start or ez start backplate if that bushing in the back plate is worn at all you will suck air in there.  Does it seem like you are chasing the high speed needle all over the place?  I know you said it quits when it warms up, but where is the throttle when it quits, are you just spooling down from a high spped run and it dies or is it quitting under accelleration? If it's when the engine is spooling down after a high speed run, I would say your low speed needle is too lean.  The trx .15 is a great engine when it has been modded correctly, the main issue with it is the block was originally a .12 sport and when they increased it to the pro .15 they didnt bother to match the block to the ports on the sleeve.  There is alot of power to be gained out of that engine if a little time with a dremel is spent on the block.  Also the pro 15 sleeve is timed very mildly, you can change alot by doing some work on the sleeve as well, but I dont recommend you do this if you do not know how to degree an engine.  There are some pretty decent write ups online that walk you through getting more out of a trx .15 just google it.  Matching  the block to the sleeve will really wake this mill up and also aloow for smoother idle, easier starting and faster spool up.  If you can find a larger carb that fits that will help as well, I dont remember which ones do- it's been years since I have worked on a pro 15.  But I have built many of them and with the right work they are screamers.