Pahtcub

I swapped out an RB concept 12 in my hpi rs4 SS two years ago and it ran fine for a year, but all of a sudden it started to die out at full throttle, I've reset to factory settings, changed the glow plug, fuel, fuel lines, and tank. I've always used after run oil. After a while driving around normal without mashing the throttle it will die by itself. Seems like it detunes when it gets hot. I've taken it to multiple LHSs and they can't seem to figure it out either. I noticed that my MVP pipe's spring was getting stuck, so I cleaned that out as well. This is really starting to get on my nerves....can anyone help me?

Pat

napalm_Fire

Have you checked your compression? If I were you, I would take the engine completely apart, clean each individual part, oil everything, and reassemble.

CLEAN THE CARB-

clean out the carb veryyy good, that would be my first thought for 'detuning' when it gets hot.

Just clean everything cleanable, and get back to us.

Pahtcub

It has compression, I can lift the car up by the pull starter at least. I'll try cleaning the carb. I can't get the engine of the motor mounts(used too much locktite apparently). Any tips on that?:-)

Pat

NitroNubee

I fell your pain, Pat! I have a non-pull start RB and it does the same thing. A very knowledgable neighbor spent an hour trying to tune it. He even flushed out the carb with fuel. We suspect it might have an air leak. I am not sure where to go from there.

Use a torch to loosen the lock tight.

Good luck!

Pahtcub

Sorry for not responding to this sooner, but I have fixed this problem...I took the carb completely apart, then washed with soap and water, then blew dry then oiled with after run oil, the blew dried, then let air dry, then oiled again and it tunes fine now. I'm so happy again!:-)

NitroNubee

Wow! Great move, Pat! I'll have to try that when I get up the nerve to take my engine apart. You know what I was going to do? Send it to Ace Hobbies. THE Rody Roem is going to be there on July 22. He should know how to fix it! Actually, I spoke to Kevin at Ace and he will give it to Rody to set it to factory specs and tune it just right. Do you think I should send it off or try to fix it myself?[8D]

Pahtcub

Well before you take the engine apart just take the carb apart, it's REALLY easy, you don't even have to take the engine out....just take off the carb, and unscrew all the needles all the way an clean them.

Pat

NitroNubee

Well, I exaggerated a little! I meant I would be nervous taking the carb out and taking it all apart. If you say it is that easy, I might try it. I looked at it last night, only one nut to loosen to take it off the engine? Then, you say back all the needles out? What about the slide portion of it? If there are not too many parts, I could pull this off!

Thanks for the tip, Pat! And the words of encouragement!

P.S. Here is a shot of my RB. Does it look similar to yours?

Pahtcub

exactly like mine, yeah just one nut to take it off, then unscrew everything, the slide doesn't come out, but the screw in it does, then the main needle comes out, the mid needle comes out, it's actually a shaft, then the brass houseing that the main needle goes in unscrews with some pliers(there's a bolt like surface at the base where it meets the carb if you look at it. If you feel uncomfortable just take it apart and if you can't get it back together take a picture and I can MS paint arrows where everything goes. There are only 5 peices if you include the carb itself. Once you get it apart you'll be amazed at how simple it really is.

Pat

NitroNubee

Hey GREAT info, Pat! I just might try it! Have you had to address any air leaks?

Pahtcub

No...that's what they thought it was with me as well...I replaced the tank and all the fuel lines, but that didn't help.

Pat

NitroNubee

Hmmmm......I thought maybe there could be one around the carb or head. I don't know, I am grabbing at straws here. I still sould like to send it to Cali so Rody could look at it and give it some TLC. What do you think? I already know he won't modify a used engine. But, I don't have the bucks to buy a new one just yet. Although, I have seen a pretty good deal for an L. Collari on this forum, I believe. I like (looks and numbers) those engines but do not know too much about them. Anyone out there have experience with them?