Thats good to hear!!! If anyone is considering one of these I know a main still has them on sale. The new Cross10 is going to be the replacement for the Shark9 but it will not be quite the performer the shark is as the Cross10 will not have the balanced crank like the Shark has.

I thought I posted this..guess I was wrong... how does the K9 perform with a 9853? lmk guys thanks

K9 has good bottom end, the 9853 is for more bottom, I would try a9886, before the 53, the 86 is for mid to top end, and probly get better fuel mileage with the 86 over the 53. I'm using the RB 2045 with the 192 header, and it works great.

Howdy.

I am new to nitro and I recently bought a used S5 L2G and it is doing something strange.

The motor starts and idles fine. When I run it around the track it has good bottom end and high end with plenty of smoke. The tuning seems fine. Once in a while when I hit a jump wrong (not a hard hit, just a small one will do it also) there is hardly any power at all. The car will move but just barely. After 10 or so seconds it will start working correctly again. Then I take a jump wrong or jar it in some way and no power again.

I have had a couple of guys that are good at tuning try to figure it out but they haven't had any luck so far.

It does it in two different vehicles with different clutches, etc. We have done an air leak test and it doesn't appear to be leaking anywhere. We have went back to factory settings a few different times and re-tuned and it still does it. The carb doesn't appear to be sticking closed.

Has anyone seen this happen before?

Thanks!!

I have..2 different times for 2 different reasons.
Check the head shims on the head button,since it was a used motor a shim may have been taken out and or your running a fuel the the nitro and oil combination is creating to much compression in the motor...try different fuel and or a different ...cooler glow plug...
On my Nova after a big jump or small one after about 2 minutes after motor was warm it would bog down after landing....LIKE a lean bog starving for fuel...,,,my fuel was creating to much compression once motor was warm.
Also on my 8.t 2.0 truggy the piece that the throtle linkage goes through thats attached to the servo horn was installed backwards and this was causing the carb to bind at about 1/3 open .

thanks

I've been out of racing for a few years now and went last weekend. I threw a rod in my S7 and I'm looking for a new RB. I've read several pages back in this thread and had a few questions. I noticed that RB is going to stop producing square stroke engines, whats the reason for this? I liked the power of my S7, it had been worked on alittle but it was very drivable. Is the S9 basically the same engine? I'm running it in a RC8 with a 2035 pipe. Is the Cross 10 replacing the S9? Thanks for the input.

Well I am not exactly sure on the reason for eliminating the square stroke engines but it could be that they are just old technology. Novarossi doesn't have any more square stroke motors so maybe it was an extra cost for RB to keep these engines in production as they are the only engines with 13mm cranks.

The S9 that is still available in some shops is the same as the S7 you are running. The WS9 will be an even better choice if you like your S7, the WS9 will have a little more power on the bottom end and more top end than what you have now but it will still be very smooth and very controllable.

The Cross10 is actually replacing several engines, the S3/Junior9, S5/Hobby9, S7/S9, WS7/WS9 were all square stroke engines and they are all going away. The Cross10 is the Novarossi based replacement for these engines, the K9/K10 is the Taiwanese engine in the lineup that is designed to give a good performing engine at a good price. (I personally prefer Nova quality)

Thats 2 of us!

Check your battery connections also, maybe a servo, or receiver too. ya never no with this stuff.

I have not really heard any negative things said about the K9. I think the only issue I saw anyone post about was a bearing going bad after 4 gallons or so. AZNitro... you mentioned your K9 is running good didn't you?

I would still rather stick with the B10's and Cross10's myself. Even on RB's site they have the K9 listed as a sport engine, where the B10 and Cross10 are listed as racing engines.

I havn't been able to run it much, with big races, it wasn't broken in yet, so, I had my WS7 III, that was fairly new, 2 gallons maybe, and a new C6, that has maybe 1 gallon, but I was palying with the K9 over the weekend, it's has some good power, good bottom, still not broken in fully, not a gallon on it yet, but I think it's good for now, we'll see what its like with a few gallons thru it. It doesn't hurt to thro bearings in an engine after a few gallons, cheap insurance.

I have about 2-3 gallons on my killer now, it runs great, barely even touched the needles after the first gallon, have been running indoors (stupid winter) It will get its first real test on a larger track here soon. Im running a thunder tiger pipe, no sign of a leak, still on 1st plug after break in(looks great) decent run time, lots of power all over for my truggy!

I'm not seeing the Cross10 or Killer9 on the rb-usa.com website. Is the Cross10 avalible yet?

10 series engines just arrived in US and will be available soon.