1 fixed & 1 broken

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RobH

Gone - bye bye.
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I solved my weird fuel problems by taking the primer pump out my fuel tank:

primerpump-fixed.jpg


I screwed up and made a mess out of the hole the pump came out of. I was able to save it by enlarging the hole to 3/8" and then making this rubber plug out of an eraser. I then ran a huge screw down the middle of the plug, enlarging the eraser, making an air-tight fit (doesn't leak when I submerge it in water and apply pressure.)

If you ever have to make something perfectly round, I found a cool way to do it.

1.) run a screw through the rubber, wood or whatever.
2.) chuck the end of the screw that's hanging out, in your drill.
3.) grab your dremel and chuck up the sanding drum.
4.) in one hand, hold your drill at full speed (thus turning the piece impaled on the screw)
5.) in the other hand, hold your dremel at full speed
6.) now take the dremel and "shape" the spinning piece.

This process makes a perfect circle. I call it the "Dremel Lathe". My wife calls it "Noisy".

Anyway, that should fix my Max ST.

The old Nitro Hawk I bought for my son, however, has a bit of a pull start problem:

nh-pullstart.jpg


As you can see, I'm gonna have to take the engine out to replace the pull start. This scares me!

I was thinking. What if I cut the cord put a huge knot in the end. Then I could use my dremel to make a slice in the side of the wheel that spools the cord (thats the red line I drew). I could then stick the huge knot I made in the cord into the groove I cut. Then I could manually wrap the cord around the spool and give it one yank. I could keep repeating the process until it starts. After it starts, I can take the cord off easy by slipping the knot out of the groove I cut.

What do you guys think? Is taking the engine off that big of a deal? The engine runs fine and starts easy. I just hate to mess with it.

-rob
 
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Is the center of pull start sitting below level of the chassis ? or what is in front of it if you can get the pull start off and can clear a 12mm socket on to the one way bearing fire it up with cordless drill ....
 
I thought about the cordless drill thing. I would have to dremel away the lip on the chassis. Also I dont have a cordless drill and from what I hear you need a beefy one to get some of these engines started. Just dont have the beefy bucks to pay for a beefy cordless drill when I have a great corded one.

-rob
 
the sears craftsman one i use works just fine and its a well worn out 14.4 and believe me when i say worn out its used everyday when I'm working ..pulling engine is nothing if you want to replace pull starter
 
Good job,
I would use something other than an eraser to make your gasket.
My concern comes from the eraser not standing up to the fuel. I would hate to see it leak air or worse yet, chunks of eraser falling into the tank.
Otherwise great technique.
 
yeah I was thinking about that. I do have a fuel filter so if it starts to degrade it wont kill my engine. I may end up having to order a replacement tank and just doing a better job taking the pump out. If it was a small hole some epoxy and a screw would have done just fine.

robd, I'll keep the cordless drill idea in mind. I think I might just try my dremel idea and if it doesn't work, no loss cause I'm only cutting the wheel that comes with the pull start anyway.

-rob
 
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I concur with Eddy on the concur about the eraser not holding up to fuel exposure. Make sure you have a good fuel filter and check on the eraser after a few runs.

As for taking the engine out to replace the pull start, do it. It may look like a lot of trouble, but it is not that difficult. Then you can replace the pull start and not have to play with a jury rigged starter. The reason I say this is that upon light off the engine recoils causing the pull start cord to get a good yank in the opposite direction. Withouth the pull start casing to feed that cord properly back onto the spool, you never know where it will end up. It may get chucked into some high rpm gears and chew up the rest of your vehicle. Just food for thought.
 
dude that truck is filthy ...i hope its right after a run when you took those pics
maybe I'm just a neat freak but i have to clean my truck after each run.
it while doing after run inspection. i always do after run inspection because its a good idea. alot of things vibrate loose and some thing might even fall off if not done.
 
as it turns out I have to take the engine off the replace the pull start. I think I'll clean it while I have the chance. :D
 
An eraser will degrade after awhile, what you what is a material called Nitrile, it is what we use in fuel aplications in yachts. it only comes in red and you should be able to pick it up at any hardware or automotive repair store.
 
Re: 1 fixed & 1 broken

Originally posted by NoviceRob


As you can see, I'm gonna have to take the engine out to replace the pull start. This scares me!


Dont be scared taking an engine out and replacing the pullstarter is cake, takes 10-15 minutes. Just remember when meshing the gears make sure the dont bind and the clutch bell and tranny gear spin good togther. Some people use a piece of paper in between the gears to get a good fit but I like to eyeball it and feel it by spinning the gears. A good way to tell is the sound its making as it spins. Give the puppy a few spins before you take the engine out to get a good feel for the way the mesh moves and sounds the try to duplicate that when re-installing it.
 
i just pulled the mill off this morning. it's an "image 12". From the looks of it you can replace your "image 12" with a pro .15 (traxxas's replacement policy). So I'm guessing a traxxas pull start will fit this guy. I'm gonna take the little bugger up to the hobby shop with tomorrow. He has a traxxas pull start in stock. Maybe it will fit. I hope so. My son is busting to have his car running again. :)

How do you know when the one way bearing is shot? I heard they cost as much as a pull start. This one seems to work still.
 
Originally posted by NoviceRob

How do you know when the one way bearing is shot? .




When it fails to operate.

while you have the pullstart off spin the bearing on the shaft and make sure it spins free in the correct direction. slide the bearing off and inspect it for wear.

I have had one that went bad and seized on the starter shaft, not a good thing. it was a booger to get off.

If you read any of the R\C mags, there is a good article in the new issue of R\C Car about one way bearings.
 
tra4070.jpg


humm looks like they sell you the pull string, the recoil spring and a plastic housing and the spool where the cord sits. Do I have to try and get this aluminum wheel off this shaft? The shaft that goes into the engine to start seems very attached to the spool the old cord used to recoil onto.
 
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i just edited my post cause I found one. I dont see the metal shaft. The spool wheel is oviously there.
 
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