Last question

is the odonnell 99 plug a good plug to use with standard plug rb's ?

Its a good plug to use, once you continue to use those, and go to an RB plug, they have a tendency strip out, but you will fine using the Odonnel 99 plug.

Thanks for the help,you to rbeamj

Hello all,

My engine us a RB S7, about 5 years old and it runs great when it gets going but if I do not run it for a couple of days, it is hard to get going.I am also having problems with the idele settings (It revs high when jumping and I am not on the trottle) I have taken really good care of it, after run oil, broken it down and cleaned it when not racing it, etc etc.

I do alot of racing but I am just wondring if it is time to get a new motor

Sounds like a potential air leak. Make sure there are no air leaks. Also ensure that you are priming the engine prior to start.

There is a video on youtube somewhere on how to check for air leaks. check for air leaks, return the needles to factory settings, then retune.

The S7 is a great little engine that lasts a long time with the proper care. It is by far one of my favorite engines with tons of controllable power and easy to tune.

It might be time for a new carb, the S7 has the older style carb with idle screw on the bottom of the carb, the newer.style has idle screw on the top side, the shark, b10, WS9, and some of.the newer Nova Rossi engine, try to pick up one of those, that will probably solve the problem,while your at it,put a new conrod in it, probably go another 5 gallons.

Generally if it is revving high when you are jumping it's either a leak somewhere like said above or your tune is off. The easiest way I have ever found to locate air leaks on my engines is to always keep the externals of the engine and carb very clean. If you start noticing wet buildup anywhere you have a leak. This is not necessarily true on the front bearing, that will leak just from running very rich at times.

How much fuel have you run thru the engine? How is the compression? Also if you run 10-15 laps then come into pit lane to let the car idle for 10 seconds what does the idle do? Have you been killing glow plugs at all?

There is not wet build up anywhere on the engine or chassis. I cannot remember how many gallons. I knew as far as idle, it can at times be inconsistant but I am more worried about the high reving when it jumps which is odd because I am off throttle. I do find myself killing glow plugs and my compression if fair to OK. I plan on taking it apart tonight to check the internals

If you seem to be killing glow plugs there may very well be slop at the conrod/crankpin connection or between the rod and wrist pin. In my experiences when the engine will rev like that in the air it may very well be the tune. It sounds to me like you have either a lean HSN or a rich LSN or a combo of both to compensate for one another.

With the wheels off the ground if you rev the engine up high for a few seconds and let off the throttle does the idle drop down nicely on it's own? Does it start high and slowly drop down and almost die? Or does it just stay idling high for quite some time?

By the way... cool lookin pup! Is that a Dobie by any chance?

The HSN is a little lean but it seemed fine when it was being driven. If I rev the engine, it does not idle high. I will break it down to see what I come up with.

FYI He is a Rott. He just looks lean because that was 4 years and 67 pounds ago

Good deal!!! I have a Dobie and when they are babies they look just like that pic. Let us know what you find with the engine.

I just ran a tank through my rc8t with s7 europa,it runs good even with 14t clutch bell just needs 13t to get some snap for corners and jumps.

Yea, the 13 tooth will make a big difference, what shoes are you using?

stock plastic shoes and stock replacement springs,I went from a .28 jpx so I was running a 14t and 15t on bigger tracks.

I'm not sure.what the stock spur gear is for the RC8, but go with all aluminum shoes with 1.0 springs. The long wear dynamite last fairly well, and the TKO clutch bearings are awsome, they last well.