My RB S7 seems to be acting strange all of a sudden im still in break in I've had about 7 tanks through her well here it goes whenever I try to go past not even half throttle it keeps cutting out for some reason I've been leaning it out(not alot but just enough to where it shouldn't cut out) trying to prevent it from cutting out but it still does im thinking theres an air leak or something. Im not sure though but when I put my finger over the exaust stinger to prime the engine on the starter box it primes the fuel but after I remove my finger the fuel goes back about half an inch or 1 inch down the fuel line again. I'm going to seal my engine again to make sure. I'm using a motorsaver airfilter and a ofna pipe on it http://www2.towerhobbies.com/cgi-bin/WTI0001P?&I=LXCWH0 When I first got the pipe I had to drill a hole through the stinger because it was blocked so I doubt that would have any affect on it but I just felt like yall should know. Any suggestions are welcome.

Oh and I left out when I opened my engine up a few days ago I found some dirt in the engine which really pi$$ed me off because I only had about 4 tanks through the engine I dont know how that much dirt got through my filter with a motorsaver on but I quickly cleaned my airfilter and the engine and polished it so its clean again Im thinkin that had somethin to do with my engine but yet im still not sure.

the fuel priming problem sounds like the tank isn't getting enough pressure!
as you had a blocked stinger it stands to reason you might have a blocked prssure nipple too, you need to remove the pipe, cover the stinger & blow down the end, you should get a steady stream of air coming back into your face, if not then clean it out til you do
the cutting out over half throttle sounds like a tuning issue, i can't tell from what you've said if its too rich or too lean but try resetting the HSN to about 2.5 turns out (factory is 3 turns & this is rich) & see how you go
as for the dirt in the engine without seeing how much & where it got to i can't say if it will be OK or not, just clean it all out and lightly oil everything before you try running it again!

hopefully you have gotten away with it & have learned the 3 golden rules of Off-Road racing

AIR-FILTER
AIR-FILTER
AIR-FILTER

i learned that the hard way myself back in my dirtbike days

good luck dude

K thanks man I'll check I feel like a total dumb@$$ right now I really hope this is a tuning issue or some stupid small problem because im very frustrated right now but thanks for your help if anyone else has any suggestions please feel free to post them.

Check to see if your compression is good in the engine still. The best way to do this is remove the engine from the vehicle and remove the clutch but leave the flywheel on. Now hold the engine sideways by the flywheel so that the weight of the engine tries to turn the piston past TDC... If the weight of the engine turns the engine past TDC then your compression is shot and a new P/S is needed.

Also I would not trust those motor-eater airfilters, I have lost two engines in my Revo due to these filters. Not sure what it is but they have let dirt through twice on me and I gave up on them. It wasn't a matter of airfilter maintenance either because I replace filter rather than clean them, I will run my heat races with one filter then the mains with a new filter.

Yeh I know how to check my compression compression is great I can yank my hand up and down and try to make the weight try to turn the piston over but it still doesn't so its good but im thinking that the glow plug is bad it still glows but I think maybe the dirt has affected it in some way anyone else think the same thing or what. I will try to run the engine again wednesday

Ohh yeah try a new glow plug for sure.. I just noticed in your original post you were breaking in the engine.. I know most time I fowl a plug during breakin. I hope that fixes your problem man I hate hearing these type of stories!!!

Yeh I hate bad too but yeh the glow plug still glows its just that im thinking the dirt must have affected it.

this is a beginner mistake BUT JUST BECAUSE IT GLOWS DOSENT MEAN THAN IT IS NOT STUFFED.
if the coil has a dull look to it then the platinum coating has worn off it and it will not work.and if there
is deposit on the end the coil it is also wrecked the dirt will not have helped either

Well I just got done running the buggy no luck tried a brand new os #8 glow plug some fuel lines from my savage and also tried putting the hsn needle back to 2.5 im stuck with the same results and im getting pissed. Im not sure what to do hopefully I will go to the hobby shop tommorow and take it under there hands for about a week or whenever they get finished. By the way im using traxxas fuel 20%. I'm thinking since dirt got into the engine and it was burnt on it has affected it but im not sure I guess I got to clean the filter every 1 or 2 runs. well I dont have the slightest clue.

dont just clean the filter replace it ever time out

OS plug probably isn't a good choice either as the OS plugs are short reach ie they dont sit far enough into the head to expose the coil to the combustion chamber/mixture properly [:'(]

just another small thing, your engine has been made at the factory to run 25% fuel!
don't waste your time with basher fuels get a decent race blended 25%

I see what are some 25% fuels I can find in the U.S. because I dont think I have seen any in my life...lol I will also order a couple new RB glow plugs. Also what do you think is better a motorsaver or a regular buggy airfilter if a regular buggy filter is better which one do you have and do you have a link I want a descent one but I cant find one I dont want it costing to expensive as I will replace alot anyways. Thanks.

Is this fuel any good http://www.towerhobbies.com/listings/cat-cat-p2.html

Or should I step up to 30%

one of the cheapest decent airfilter setups is the kit standard XB8 filter assembly, its half the price of the RB airfilter, plus you can use the Rb foams on it that should be freely available
i have had ZERO filter issues using these parts

Get the Mugen or XRay filter setup with some [link=http://www.power-save-racing.de]Power-Save-Racing[/link] filter elements (you can get them from [link=http://www.amainhobbies.com]A-Main[/link]).

The problem with the motor saver is the front lid. Even if it doesn't fall out, it lets dirt directly to the inner filter element and maybe even past it. If you're using one, also check your Ofna header. They are sometimes cluttered up with excess aluminium because they're not welded on correctly. You might have to dremel it out there.

Well I've never tried any other fuel before but is 30% good and are brands like o'donnel and sidewinder good for this engine or monster horsepower fuel by trinity and theres also a race blend from trinity

Well I've picked sidewinder fuel with 30% and 11% oil http://www2.towerhobbies.com/cgi-bin...?&I=LXHCU2&P=0 its says its for helicopters yet I found it in the cars/boat section so idk... but yeh anyways anybody know where I can buy this fuel in 1 gallon container that will ship. And can anyone show me a xray filter preferably on the same site as the 1 gallon 30% sidewinder fuel. Thanks and is this what you guys were talkin about the little filter that will fit the xray filtration system http://www.amainhobbies.com/product_...oducts_id/4094

Hey guys I finally bought some 30% fuel but still I have had no luck with it yet the Filters are changed to brand new ones I am still having the same problem. Right now I think the problem is the engines front bearing sometimes I'm finding some wet dirt particles right beside the fly wheel and where the front bearing is. Do you think its still under warranty or what. I'm stumped This is the only engine I"ve had besides my cen that I've had serious problems with. Even if I touch the needles it doesnt make a difference if I lean the hsn out to where it should not cut out the cutting out gets even worser and when I richen it the temp is probably around 200 and its super rich and sometimes the temp is low right after a cold start. I think I will be calling RB or take it to my lhs to see what they can find out. What do yall think? I would greatly appreciate it!

Okay... everything that you've heard.. forget it.

Here's the issues.

The reason that your engine is cutting out at higher throttles is because IT IS STILL NEW. That RB S7 will take min. 1/4 gallon before it really starts to break in. If you get lucky you will get one that takes almost a gallon. That means it will last a loong time.

I wouldn't run that pipe with that engine. You have a killer engine, don't cheap out. Get a JP2 for it. Or an OS 2050. They cost but they are worth it.

Get O'Donnell 30% fuel and O'Donnell 99 glow plugs.

Throw that motor saver air filter away. Get a real filter. Mugen makes a great one. XRay's is good as well.

Everyone @ my track runs almost exclusivly RB engines.... There's been 4 S5's broken in this week... every single one of them does the cutting out at high speeds. I don't know how you broke it in but try to get your temp in the 220 - 240 range and don't run the car to fast. Drive it around sort of slow with little bursts of full throttle. 1 - 2 seconds for now. do that for a little bit and you'll see it start to work better.

Heck if you still can't get it to work right ship it to me with money to ship it back plus fuel and I'll break it in for you.

Alright I will see if that helps do you think the rb #6 glowplugs will work better than the 99's. Well Im going to continue using trinity monster horsepower 30% fuel and see if its good. So your saying that the RB are basically all like this from the beginning that the engine tries to cut out while trying to hit high speeds? I hope your right I would hate to put too much fuel through the engine for still poor results. Dont worry about the pipe it is temporary for now I was thinking about getting a JP-1 and some power racing filter elements along with a mugen airfilter set.

rb engine .....use rb plugs. get wat u pay for

My S7 took over a gallon to break in and lasted 10 gallons! Patience grasshopper it will pay back 10 fold if you take your time breaking it in. Trust me it will be a bullet. But remember whenever you change pipes or plugs you will have to retune it.

K thanks i will see what happens

The RB Plugs will be fine. with 30% get a cold plug. I'm not familiar enough with the RB ones to say for sure but I think the 6 is a medium/cold plug. I know I used one in my NovaRossi while it was in the process of dieing so I only got abot 30 seconds out of it.. lol

I haven't used the Trinity fuel but it's probably okay. You'll have to see I guess. If it still won't work right then try some O'Donnell if you can get it.

And yes, that's what I am saying - it's not just RB's it is any quality motor that will act that way untill it is broken in.