2 Nitro RC trucks... both dead... argh..

[bigredhead]

Aight.... anyone know much about these Nitro glow motors ?

I got 2 trucks right now.

1- HPI Nitro RS4 MT

2- Traxxas Revo 2.5R

I'm currently trying to get the HPI going..

Have :
- Changed fuel
- New Glow plug
- Cleaned carb ( set the air/fuel to 3 turns out.. 4..3.5 etc.... and the gap at 1 mm .. also tried 2 mm and with throttle partially open on the controller )
- New battery in Plug igniter ( swapped it multiple times.. with Nimh and new alkaline AA )
- Changed fuel lines for transparent tubing so i can see the fuel getting to the carb..
- Removed air filter.. cleaned it .. tried with and without the filter installed.
- Checked line from pipe to fuel tank.. not clogged


Won't even sputter for a few pops.. my arm is killing me from pulling the darn rope.. :lol:

I'm outa ideas... anyone ?


The Revo... that's another story.. but i want to concentrate on one at a time here..

[Rm250RF900R]

These things are really hard to tune. I had one. It was like keeping a pet hampster. Always had to do maintence.

[bigredhead]

I"m fine with doing all the maintenance needed.. but i wish it would at least POP or fire for a few seconds.. but as it is .. nothen.

[tecate kid]

Does the motor need a new piston? I would maybe try rebuilding it then start from there. Oh, and maybe look into a electric start setup for it.
tecate kid

[slothminx]

heh, I was just playing with mine a little earlier, and my buddies Traxxax.

Theres a certian trick to starting the different engines, on the Traxxax you take off the air filter and put your finger over the intake for a few seconds then take it off and it fires. On my car, you set the trim to give it a tiny bit of throttle and pull away.

Try using a finger over the intake and pulling away.

[traxxasx]

sorry to hear that. does it have compression? what percent of nitro are you using? somtimes putting you finger over the muffle to clog it and pull the rope some then let off with get it to fire. maybe it needs a new carb? if all fail try taking it down to your local hobby shop and let them look at it. im currently waiting for my new hpi rs4 to come in the mail should be here on the 27th/

[bigredhead]

Using 20% nitro. Fresh jug, only a few months old, almost full.. always capped. ( i even took the bottle out to the driveway and tested it's flamability !! hehe.. )

The HPI has low compression, i turn the spurr gear with my finger and it's easy to turn.. compared to the Traxxas wich resists turning and gives a nice POP.. Time for new motor huh...

[ScottZJ]

Hey man, sounds like its alittle too late but I found the glow plug lighter yesterday. That head was recently replaced as the other one got stripped out where the glow plug mounts. But on the old head, I would do as stated above and clog the pipe for a second and it would start. But I never really ran it (since it was muddy most of the times I brought it out lol).

[bigredhead]

Any idea how much fuel was used on the existing piston/sleve ? I took it apart and it looks like new.. Might be some kind of air leak..

I picked up an igniter locally last week, had the itch to get it going .. hehe..

[ScottZJ]

The guy I bought it from said it had low hours on that motor, cuz he put a modded motor on it and didnt use that one much at all. Check the fuel lines and air filter area.

[bigredhead]

I see..

Well. i'm no quitter.. so if i have to tear down the whole motor and inspect the whole deal.. it's what's gonna be done.hehe.....

Some how.. some way... it will run !

[bassman]

Well, first thing I'd do, is take of the pull start, and keep the one way bearing hex. Then rig up a cordless drill with the matching socket, thus eliminating all arm soreness. I finally got tired of always having to pull start my Madforce, so I just pulled it off and used this way, and I'll NEVER go back.

[bigredhead]

I was considering such a thing.. it does not create any air leaks by any chance ?

[Somekindofjerk]

Those little cars are a blast, They rev like crazy and are actually quiet fast. they have to be very tight as far as ring gap, seals, and fuel intake... Were you able to find specs on them?

[bigredhead]

Well.. last night i took the motor out.. took it apart.. cleaned everything spotless and applied " copper seal " that orange silicone stuff, VERY thin.. no globs etc.. to make sure i have no air leaks.. from the pull start plate and cylinder.. exhaust.. carb etc...

New fuel.. changed to a brand new glow plug.. 3 turns out from seated for the air/fuel.. new battery in igniter, fresh tank full of fuel... and still no go. :wondering

I was gonig to mount a nut to the shaft to use a drill instead of the pull start.. but it's a smooth shaft.. no grooves or threads .. the pull start just slips on and when you pull it side loads the shaft to make it go.. not sure how to make it work without buying the cordless drill kit for it.

[bigredhead]

Well.. last night i took the motor out.. took it apart.. cleaned everything spotless and applied " copper seal " that orange silicone stuff, VERY thin.. no globs etc.. to make sure i have no air leaks.. from the pull start plate and cylinder.. exhaust.. carb etc...

New fuel.. changed to a brand new glow plug.. 3 turns out from seated for the air/fuel.. new battery in igniter, fresh tank full of fuel... and still no go. :wondering

I was gonig to mount a nut to the shaft to use a drill instead of the pull start.. but it's a smooth shaft.. no grooves or threads .. the pull start just slips on and when you pull it side loads the shaft to make it go.. not sure how to make it work without buying the cordless drill kit for it.

[Rm250RF900R]

Might be just easier to buy a new O.S engine for it. www.towerhobbies.com... Great place.

[traxxasx]

lol is cause the shaft is like a on way magnetic shaft. its weird. id go buy a new motor.......

[750fl]

Did you prime the motor and do you have any leaks in you fuel tank. To prime the motor asuming you don't ahve a primer on the tank. Put you finger over the tail pipe and pull it a few times. That should get the fuel into the carb. You never want to use silicone with copper gaskets.

[bigredhead]

Just got back from playing with the Revo 2.5R.. man that sucker is fun when it runs !!! :Bounce


The HPI is still not starting.. i did not silicone the glow plug.. But i did seal the plate that goes between the pull start and the crank.. and the cylinder to the exhaust pipe.. and also the cylinder to carb conection.

But at least i have one running at the moment.. first full tank of fuel i have managed to burn without stalling.. :D .

Had an adventure with the Traxxas nimh charger.. hooked it up to a 12v battery to charge the truck.. and no lights.. test the lead acid battery and it's fine.... so i open the charger and the fuse is blown.. now... would you not think Traxxas would make this fuse re-placable... nope.. had to break it to bits to remove it and solder a new one in.. Got the truck re-charged and WRRRREEEEEEEENENNNNN