jakesterama

Hey all,

I have mostly an electric guy but I picked up a used REVO with an aftermarket OS .21 engine for some back yard bashing. I had it out for the third time this past weekend and about halfway through the tank I lost all power. I ran over to the truck and it was idling just fine, but when I applied the throttle it made a grinding noise from the flywheel area, and didn't have enough power to turn the wheels. I thought I saw a spark or two fly off on the way over to it too.

Is this a bad clutch? If it is do I look for something from OS or from Traxxas?

Also, is there a good way to clean nitro residue?

Sorry if these sound dumb...

EDIT: also, I want a new muffler because it came with a large pipe mounted diagonally across the electronics and it gets the thing full of oil. I like the way the dual pipes on eBay route the exhaust out the back, but I hear they are loud and rob power. Do I need a special pipe or will any stock Revo pipe fit because the OS.21 was designed with the Revo manifold?

racemaxx24

The problem with the clutch sounds to me like either a spring broke on one of the shoes or its a metal clutch and the pads are just worn out. Where to get the parts from really depends one what kind is in it, best way for us to help you is by taking to motor off and taking to clutch bell off and then taking some pictures and posting them.

Try something like this for cleaning up nitro residue and such: http://www3.towerhobbies.com/cgi-bin...&I=LXTMF3&P=ML

The stock pipe/header combination works pretty good IMO but the header tends to break if you have a hard rear end impact. That's why some guys do a normal route to the side. The Resonator pipe Traxxas sells is a good set-up for performance and such but the stock is a pretty good performance pipe already.

LMK if this helps.

jakesterama

Hey, thanks for the reply! I was worried this would just be a dead post
Here are some pictures. The clutch looks pretty worn, but I don't know how worn is too worn.

Also, is my spur too loose?
[youtube]http://www.youtube.com/watch?v=rdC1XyRSbPI[/youtube]

racemaxx24

The clutch shoes most definitely look shot. The sparks are probably coming from the clutch springs rubbing the the clutch bell. I'll look around at Tower and see if I can find some shoes that will work.

And there is also something wrong with the the transmission. Either a bearing has gone bad or it could just be a loose screw. Try pulling the transmission out and open it up and see if you can see anything. Like I said, it could be a simple loose screw or it may have a bad bearing. Just remember where everything goes.

quadracer111

My Feedback: (1)

Wowzas [X(] Something is wrong in your slipper clutch area. It isnt suppose to do that at all! Try tightening the 3 hex bolts that you can see when looking at the face of the spur gear. Make those nice and tight. It is the nut by the spur that you loosen and tighten to adjust the slipper. http://www.misbehavin-rc.com/pit-lan...adjustment.asp In that first picture on that link you can see the 3 screws I am telling you to tighten all the way.

jakesterama

Hey, thanks for the replys!

I ordered a slipper rebuild kit and some new clutch shoes+springs. The 3 allen screws on the spur are as tight as they go, so I think I would need to add a washer or two to make the gear snug.

I still can't find a concrete answer on what type of pipe I should get. OS sent me a reply that said to use the stock Revo pipe, which really doesn't help me because I don't have one, nor to I have the stock, OR the 'big block' kit's header. I think I am just going to order the THS1046 and then pick up the Traxxas Big Block Header #5425 if it doesn't fit....

I took out the transmission and inspected all of the parts. It looked surprisingly new in there, almost like it was replaced recently. All of the gears and mesh looked good, and all the bearings spun well.

nargargle

Your slipper clutch is broken.  It can be seen in the pics if you look closely, and it is missing the springs/bellville washers (part # 5352).  As per your engine clutch, your clutch bell is set too far out and the gear mesh is off.  I don't know if you can slide the engine toward the rear of the truck or not but the clutch bell gear and the pinion gear should be centered relative to each other.  your clutch bell gear is hitting part of your slipper and may be what caused some of the damage.

Hope this helps.

jakesterama

You are right, there is no spring, how did I not notice that before.... The rebuild kit comes with the spring though. Unfortunately the engine mount system looks to be all hole-for-hole line ups with no chance of adjustment. We will see if once the slipper is properly installed and the engine is properly mounted (I was missing a screw and the other 3 were loose...) how the pinion and spur line up.

Thanks again for the replys! Any incite on the header dilemma?

jakesterama

Well OS replied and said to use the included header, which I already told them I didn't have... Looked up the part (#OSM72103810) and it is almost fifty bucks! BUT it is the same that comes with the OS 18TM. The THS1046 states that "Will also work on OS Max 18TM Engine" vis-a-vis THS1046 should work fit the OS 21 right?! Well I hope so because I picked one up.

jakesterama

Well, I was incorrect. The header doesn't even fit over the bare exhaust port on the OS21TM and even if it did the bend is far too reserved and the pipe is too long for it to fit in the proper position. Dangit. I requested a return and I am picking up a Trinity and hopefully between its two headers and multiple gaskets I will be able to make something work.