Fuel delivery

[sgra2951]

My brother just sent me a Traxxas T-Max and I have not been able to get it running. I replaced the wiring harness, fuel lines, glow plug and new batteries. When I try to start it the motor cranks but wont take. I took the fuel line off and held the muffler and I got fuel to pump through the line, but as soon as I put the line back on the motor and try I get no fuel through the lines. I am so confused, I dont know what to shoot for next! Any help would be greatly appreciated..

-New User-

 

[andydrew39219]

Has the motor been broken in? You do not have to take the fuel line off to prime, if you prime by plugging the exhaust. But you can also just take the line off the exhaust and blow into it to to prime. That's how I do it. I have had problems with getting my nitro to start and it usually is just getting it primed enough. But not too much and you will flood it. Do you see anything coming out of the muffler? If you do then you might have to set the carb to factory settings. What temps are you trying to run in?

 

[sgra2951]

UPDATE!
Engine is broken in, put fuel in carb and it RAN!! But only until the gas ran out.. Then it stalls..

---------- Post added at 12:48 PM ---------- Previous post was at 12:47 PM ----------

not to sure what temps, I have adjusted the carb back to 2 full turns and one half turn.. Still can't get fuel to deliver..

 

[Skwerly]

Is there a pinhole leak in the line?

 

[andydrew39219]

UPDATE!
Engine is broken in, put fuel in carb and it RAN!! But only until the gas ran out.. Then it stalls..

---------- Post added at 12:48 PM ---------- Previous post was at 12:47 PM ----------

not to sure what temps, I have adjusted the carb back to 2 full turns and one half turn.. Still can't get fuel to deliver..

You do a have pressure line running from your tank to the exhaust right? When you open the tank can you feel or hear a little bit of suction? Maybe the seal on the tank is bad. If you got it to start by manually putting fuel into the carb, then it sounds like you have no back pressure from the exhaust.

 

[sgra2951]

Line to exhaust check. Seal on the tank.. good. When i blow into the exhaust line I still cannot get the fuel to prime. When I pull line from carb and blow into it, I get fuel to push throu.

 

[andydrew39219]

Line to exhaust check. Seal on the tank.. good. When i blow into the exhaust line I still cannot get the fuel to prime. When I pull line from carb and blow into it, I get fuel to push throu.

When you blow into the pressure line can you feel any pressure? or is it just like blowing into an empty line? There's your problem, the question is, is what exactly the problem is. How did you put fuel into the carb?

 

[2revo1maxx]

2 full turns and 1 half turn? Which needle was that? You have to set the low speed needle at 1.5-2 full turns out and the high needle at 4-4.5 turns out. Make sure the idle gap is set to 1mm or less and also make sure the slide is fully closed (1mm) against the idle stop when you set the low needle.

---------- Post added at 3:21 PM ---------- Previous post was at 3:16 PM ----------

Here's a pic, but it's a different brand carb:

http://images.search.yahoo.com/imag...b=13n0d3vjb&sigi=11dj9c0bb&.crumb=qP1K5ktDfLD

 

[sgra2951]

Got it tunes in right.. Now i am having transmission problems. I took it all apart and everything seems to be in place. Replaced slipper clutch (72 count), new bell housing (21 count) got mesh down properly too. BUT... When I hit the throttle, it revvs up and nothing moves. Got slipper clutch to the max torque just to make sure its not slipping. Truck moved some but nothing like it should.. Also, Brake/acceleration servo is not pulling on the brake side hard enough.. So I have no brake. I am htinking this is an adjustment on my JR X3 Pro remote but am looking into it. right now, I'm still a week into this re-build project and truck has no more than 5 minutes of run time. I am so lost on the tranny problem.. Everything looks to be great! But no movement.. at least not like you would expect..

 

[andydrew39219]

Got it tunes in right.. Now i am having transmission problems. I took it all apart and everything seems to be in place. Replaced slipper clutch (72 count), new bell housing (21 count) got mesh down properly too. BUT... When I hit the throttle, it revvs up and nothing moves. Got slipper clutch to the max torque just to make sure its not slipping. Truck moved some but nothing like it should.. Also, Brake/acceleration servo is not pulling on the brake side hard enough.. So I have no brake. I am htinking this is an adjustment on my JR X3 Pro remote but am looking into it. right now, I'm still a week into this re-build project and truck has no more than 5 minutes of run time. I am so lost on the tranny problem.. Everything looks to be great! But no movement.. at least not like you would expect..

That's the issue with getting a used R/C, it can be overwhelming. But, don't worry, don't give up, once you get it you will love it. You said when you throttle up nothing moves, is your clutch bell moving, even at an idle? That's the first step, if that is not spinning then you have clutch/flywheel issues. If it is spinning we move down the line, ok so Clutch bell is spinning, is the spur gear spinning? You said the mesh was good, and if the clutch bell is spinning the spur should be. Ok! spur gear is spinning lets see, what about the pegs that hold the spur gear? I have actually never taken it apart before so I don't know what to expect. Correct me if I'm wrong, But I'm pretty sure when you take that nut and spring off the spur gear, you get rubber pegs that are smooshed in between those plates on the spur. and I have read about those pegs wearing out, maybe that is your issue? Ok, good pegs and spur! Now to the tranny. You said you got the truck to move, How did it act? was it just jerking forward? or was it rolling? Hear any weird noises? Have you played with the wheels at all. Spin both of the front tires at the same time, hear any clicking? Feel resistance? Do it to the rears afterwards, same deal, clicking? resistance? other noises? When you are spinning both the front tires, what are the rears doing? What about when you are spinning both rear tires, what are the fronts doing? Roll it around on all wheels on the floor, Do you hear any bad noises from the tranny or diffs? If you can do all that with any problems your tranny is probably fine. The diffs in my Tmaxx click pretty bad and I didn't notice anything until I pulled the diffs out of the truck and played with them.

About your throttle and brake problem. I would reset the transmitter to all default and then your going to have to adjust the linkage if it is still not correct. Adjusting the throttle/brake linkage is a pain, I still don't like to mess with mine.

Whew, that is one wall of text. Just trying to be thorough, I want you to get this truck running.

 

[sgra2951]

I wil look into it again maybe this morning. As far as I remember the bell is spinning, as well is the spur gear.. When It moves it doesn't jerk, it moves quickly, but wh nit moves you can hear it click into gear.. like its snapping into gear. Replaced friction pegs in spur gear, havent taken diff's apart yet thou.. But, when I spin both front or rear tires in unisen, I get the fronts to move as well.. I had a friend tell me that maybe I need to take reverse out.. I think I may try this.. Truck runs great, I jsut want to get this tranny problem resolved... Frustrating it is..

 

[maddmaxx65]

I had the same problem years ago when I first got in this hobby i spent 300 dollars trying to fix it and same proplem what it was is I bought fancy fuel lines and they didnt fit the nipple tight bought little zip tyes and problem solved

 

[andydrew39219]

My tmaxx makes a pretty loud/unpleaseant noise when it engages into gear too. I wouldn't be worried about that. Make sure your forward/reverse linkage is all the way in. So it is in forward. The used tmaxx I bought, the shifter servo is toast. I still run it without problems. Just adjusted the linkage so that it was really being forced into the trans, so it wouldn't come out of gear.

If you spin both fronts, then both rears spin with it?
Is you spin both rears, then both fronts spin with it?
What about just one rear? or one front?

Even if the diffs need rebuilding you should still be able to drive it around. both of my diffs click and I drove my maxx around for probably 5-10 tanks after I got it without problems.

I don't know what else to tell you, If you truly think it is the tranny, then replace or rebuild it. Rebuilding the diffs can't hurt either.

 

[sgra2951]

My shift linkage servo is also toast. It barely moves when I tell it to, so I just removed it and pushed the linkage in myself.. If I turn one wheel only then the other wheel spins but in a different direction., and the opposete alxe wheels do nothing.. I am going to purchase the part that removes reverse from the tranny and see where that gets me.. Thanks for all the help. I think I am going to keep working on it, as a project vehicle but I may go get a new savage X 4.6 this weekend so that I have something to at least play with now..

 

[andydrew39219]

The shifter servo is toast in my maxx too. I cut the wire off of it and set the linkage so it would always be pushing in to the tranny.

The FOC is probably a good idea, it will give you a chance to poke around the tranny and look for any broken pieces, etc.