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My first post..... - I have some questions, see bottom of this post -
This is day 1 with my rc10gt and my new OS .18 CV-RX (s) engine. I am 4 tanks into breaking it in. My fingers are scraped, scared, torn and bleeding from the %@#$% pull starter.

This is what I did to the parking lot. I'd like to tell you the marks are all from me tire shredding, and some of it probably is, but most is from the exhaust deflector and the super rich mixture.







Is there an adapter for this??




So, my first impressions? I'm still breaking it in and this has RIDICULOUS power! Those brand new tires are visibly worn down from 4 tanks of (mostly) gentle breaking in.

I do have questions though....
*I want to run the exhaust under the chassis and out the back via a tube like a longer version of that exhaust deflector. Can I buy such a thing? Helps keep the truck cleaner.
*Also, the truck moves forward while idling. How do I stop this?
*Underneath the exhaust manifold is soggy and messy with some fuel leaking out? Is this normal? How should I fix it?
*The front has NO weight. When I steer, they front don't really grab. Could I use counter-weights?

Justin428 wrote:I do have questions though....
*I want to run the exhaust under the chassis and out the back via a tube like a longer version of that exhaust deflector. Can I buy such a thing? Helps keep the truck cleaner.
*Also, the truck moves forward while idling. How do I stop this?
*Underneath the exhaust manifold is soggy and messy with some fuel leaking out? Is this normal? How should I fix it?
*The front has NO weight. When I steer, they front don't really grab. Could I use counter-weights?

Welcome to the forum.
You could rig something up to run the exhaust out the back, but there's a very good chance it would keep the exhaust from working properly. The air flow through there is very important for the engine to run properly.

If you tighten your brake just a hair it will stop the truck from moving forward, but you need to be careful to keep it loose enough so that it completely lets go under throttle.

As for the mess, you may as well just get use to it. Nitro is a filthy mess. The mess and the finicky nature of the engine is why I converted my GT to electric. It's pretty much impossible to stop all the leaks. They just seem to spit nitro out everywhere. It's very annoying.

Weights are fine.

As for the adapter question, I'm not sure. You may be better off just putting on a new plug or making your own adapter.

THEYTOOKMYTHUMB wrote:

Justin428 wrote:I do have questions though....
*I want to run the exhaust under the chassis and out the back via a tube like a longer version of that exhaust deflector. Can I buy such a thing? Helps keep the truck cleaner.
*Also, the truck moves forward while idling. How do I stop this?
*Underneath the exhaust manifold is soggy and messy with some fuel leaking out? Is this normal? How should I fix it?
*The front has NO weight. When I steer, they front don't really grab. Could I use counter-weights?

Welcome to the forum.
You could rig something up to run the exhaust out the back, but there's a very good chance it would keep the exhaust from working properly. The air flow through there is very important for the engine to run properly.

If you tighten your brake just a hair it will stop the truck from moving forward, but you need to be careful to keep it loose enough so that it completely lets go under throttle.

As for the mess, you may as well just get use to it. Nitro is a filthy mess. The mess and the finicky nature of the engine is why I converted my GT to electric. It's pretty much impossible to stop all the leaks. They just seem to spit nitro out everywhere. It's very annoying.

Weights are fine.

As for the adapter question, I'm not sure. You may be better off just putting on a new plug or making your own adapter.

I'm having some trouble setting up my throttle/brake linkage. To make matters worse, I seem to have every hex size except the surgical/needle one that adjusts those little set points on the throttle linkage. When I hit the brakes, the carb is shutting, killing the engine.

I would think that as long as the exhaust tube idea doesn't constrict the exhaust and remains a constant diameter it shouldn't hurt anything. But, I'm not a 2 stroke pro either.

Oh, and I loosened the nut on the spur gear, hoping that helps with the truck running forward when no gas is applied.

I love the *idea* of nitro but I would ultimately just get way too frustrated with all the tuning and stuff. I have a real car that has enough issues for me already

Good luck with the GT

IM definatly no nitro expert but if its taking off on idle, either the idel is set too high or the clutch is grabbing or out of adjustment

You can try to adjust the low speed needle down a millimeter. Make very very small adjustments, do a few runs back and forth and make another adj until it sits at idle.

I am no nitro expert either, I have a few and do not run them much at all anymore. Like Todd said, get used to the mess. It is fun and I like it but it gets old after awhile.

You want a good amount of exhaust while it is ripping back and forth, the less exhaust the leaner it is running and the hotter it gets. Not always a good thing for a nitro engine.

If you do rig something up to run the pipe out the back, make sure it is a tad larger on the output end. The exhaust has to travel that much farther and can affect the compression at the output.

Try a few different lengths of tubing or pipe, maybe a few different directions of exhaust output as well. Make some runs after each change and see what you like best.

Nitro is finicky, but with the right set up it is great. I can't tune worth a shiz, but I still try once in awhile.

Ah.... The dreaded throttle/brake linkage question.... It would take several paragraphs to really explain it properly, but I will give you the short answer and try to get you going in the right direction. First disconnect the throttle and brake linkages from the carb arm and brake cam. Next, set the idle gap on your carb to 1mm. Make sure you radio trims are centered before you connect anything. Start with the throttle linkage only at first, get that working right. Next move onto the brake linkage. Once you have set the throttle the brake will be easy.

The "creeping" (the truck trying to move at idle) is inherent to the springless design of the stock clutch, and its actually the least of the problems with the stock clutch. The stock clutch is crap. It can be made to work ok, but at best it its finicky, and it its constantly engaged witch causes overheating issues. You would be doing yourself a huge favor by getting an mip clutch. They cost about $15 and are the single best mod you can do to a gt. They have a spring, which its the main benefit, but they are also adjustable, and just work great in general. They will also last forever if it its setup properly.

Ruining the tube for the exhaust is a bad idea. Again, it would take several paragraphs to explain it properly, but in short, two strokes are very sensitive to exhaust, and the stinger is set at that length for a reason. You probably could get it to work, but these little engines are finicky to begin with changing the exhaust that much is just going to make it that much harder to tune. Even the extender you have now is having an effect, just not enough to really notice it. Also, you should not have the extender pointed towards the ground, it should be pointed at least slightly up. It is not likely, but it is possible for the exhaust to suck dirt into the engine. Also, keeping it pointed as high as possibly will keep the truck as clean as possible. However, like had been said, it is a nitro, you can forget about keeping it really clean. Another option would be an mip stinger exhaust system. The pipe actually wraps around and exits the rear. However they are no longer being made, so you will have to search for one.

Fuel should not be leaking out of the engine/header flange. You have a sealing issue there. It probably just needs a new gasket.

Also, if you are wearing down your tires, you are being way to hard on your engine for a proper break-in! You really don't even need to drive your truck to do a break-in. Take it easy. A little patience now will go a long way in the long run.

justinspeed79 wrote:
The "creeping" (the truck trying to move at idle) is inherent to the springless design of the stock clutch, and its actually the least of the problems with the stock clutch. The stock clutch is crap. It can be made to work ok, but at best it its finicky, and it its constantly engaged witch causes overheating issues. You would be doing yourself a huge favor by getting an mip clutch. They cost about $15 and are the single best mod you can do to a gt. They have a spring, which its the main benefit, but they are also adjustable, and just work great in general. They will also last forever if it its setup properly.

Did they change clutch parts with the blue pan truck? Back in the day of running my black tub it came with a small piece of steel that was shaped into a spring that connected the two halves of the clutch together. I always ran a little drag on the bakes at idle position but even at off brakes position my truck still sat still with stock clutch. I can get pictures of the stock clutch spring later just curious if this was deleted on the newer models. If so it could easily be made.

The stock clutch spring only came in the first few kits and they did away with it for some inexplicable reason. And it was like literally the first few from what I can gather. It was gone before the white parts were.

I have thought about making one, it definitely could be done. It would have to be spring steel though, not sure where to source it that size. I never pursued it because I just don't see the point running anything other than the mip, it really is that good.

Thanks for the replies.

The carb seemed very loose and poorly built so today the whole engine got sent in to Hobby Services. The idle set screw did nothing at all and the glow plug leaked fuel from around its hole. Maybe I got one that was built on a Friday afternoon?


So anyway, I expect to have it back in a few days. While its gone I better work on this exhaust manifold. Seems the hole is way too small for the port of the .18. Using the gasket, I marked in red the area that needs to be filed away. Is this necessary or can I just buy a proper fitting manifold on ebay or somewhere else? Which muffler to use for this engine? It has low end so I think a muffler with top speed in mind would be nice.

justinspeed79 wrote:Also, if you are wearing down your tires, you are being way to hard on your engine for a proper break-in! You really don't even need to drive your truck to do a break-in. Take it easy. A little patience now will go a long way in the long run.

i did get a little carried away, perhaps. I'll try to keep that in check in the future.

justinspeed79 wrote:Ah.... The dreaded throttle/brake linkage question.... It would take several paragraphs to really explain it properly, but I will give you the short answer and try to get you going in the right direction. First disconnect the throttle and brake linkages from the carb arm and brake cam. Next, set the idle gap on your carb to 1mm. Make sure you radio trims are centered before you connect anything. Start with the throttle linkage only at first, get that working right. Next move onto the brake linkage. Once you have set the throttle the brake will be easy.

The "creeping" (the truck trying to move at idle) is inherent to the springless design of the stock clutch, and its actually the least of the problems with the stock clutch. The stock clutch is crap. It can be made to work ok, but at best it its finicky, and it its constantly engaged witch causes overheating issues. You would be doing yourself a huge favor by getting an mip clutch. They cost about $15 and are the single best mod you can do to a gt. They have a spring, which its the main benefit, but they are also adjustable, and just work great in general. They will also last forever if it its setup properly.

This is going to be a PITA. Oh well.

Matching the manifold port is a common mod, just be careful not to take too much off and compromise the sealing surface. You can also cut 3/8"off the end of the manifold and it will give you a bit of a torque boost. Neither one add a lot, but it works and its fee. Not that you really need a power boost with the .18.

The throttle/brake linkage is not that bad once you start playing around with it. It will "click" eventually.

Sorry to hear about the engine problems. Must have been a dud. OS's quality is usually very good.

justinspeed79 wrote:Matching the manifold port is a common mod, just be careful not to take too much off and compromise the sealing surface. You can also cut 3/8"off the end of the manifold and it will give you a bit of a torque boost. Neither one add a lot, but it works and its fee. Not that you really need a power boost with the .18. 8)

The throttle/brake linkage is not that bad once you start playing around with it. It will "click" eventually.

Sorry to hear about the engine problems. Must have been a dud. OS's quality is usually very good.

Yeah I tend to get duds. :(

As for cutting 3/8" off, you are of course referring to the portion touching the Chapstick cap and not the manifold connection right? Just checking.

And I don't have a dremel, so this could be tedious by file. Is there a better exhaust other than the rc10gt one?

You're a Justin, too? My parents said it wasn't a common name in '80. Whatever!