hobdog

iTrader: (19)

So here is the deal. The guy I race with and myself are both having the same problem and we are stumped. Both of our truggys for the first four to five laps are real fast, but seem to fade a bit through the middle to end of our tanks. We have a double double section in the track that is a real easy for us to tripple single at the begining of the race, but as it goes on I can't got it. What would cause this for both of us?

wingracer

iTrader: (24)

Sounds like you are too lean. The motor should be running a bit rich until it gets good and warmed up. Try to richen it up just a hair and try again.

Also, too lean on the LSN can cause a fade due to overheating as well.

Or, clutch may be going soft when it gets hot and killing your bottom end torque.

imaxx21

iTrader: (1)

+1 being too lean

in your warmup laps the engine should feel rich till it gets up to operating temp

hobdog

iTrader: (19)

I guess that might be the case as to being lean. What is strange is that on my nova 821b that I run, I have always been around the 200 degree mark and it has excellent power. I did lean it out a bit this last time, and got it to the 230 degree mark, which I am sure was still real safe, but maybe this engine does not like to get that hot.

slaytanic

iTrader: (20)

Don't trust your temp gun. It COULD be off 20 or more degrees easily. Just tune it so it runs nice with good smoke then temp it. Use that number as a ball park.

motomanpat

iTrader: (2)

I would first have to ask how many gallons of fuel have you run through your engine?

notch johnson

Your motor is shot- lost compression- thats why it only runs when its cold- buy another one and start FRESH or get it pinched and continue to suffer

hobdog

iTrader: (19)

Not the case. How could you even say that with the little amount of info I gave. My engine has just over one gallon of fuel through it. I ended up richen it about 5 hours on the high needle, and 3 hours on the low and it ran great today. It was strange, all I did was seal the carb and slime the needles o rings, but something to do with that had a real effect on the jetting.

dodgeguy

iTrader: (208)

Check your front bearing. If you have any oil on the front of the engine it is leaking. This is usually over looked it seems. I had one leaking on an RB S7. I could not get the carb tuned when the engine was warmed up. Your problem sounds a little like what I had. i replaced the $9 bearing and it runs perfect now. I had 2 gallons on the bearing when I replaced it.

hobdog

iTrader: (19)

my front bearing is leaking pretty bad. I got the engine running real well last night. I think I should replace both bearings at once, I just hate to open her up when I got it running well.

dodgeguy

iTrader: (208)

That front bearing is your problem. I would replace the bearing. You do not need to replace the rear unless you really want to. I would also adjust all your carb settings to the base starting points. Since all of your adjustments are with a leaking bearing.



Here is a how to on RB's site. This will work for most other engines. As for the heating I used my in laws stove top with a glass surface. Worked great.

http://www.rbproducts.com/mainEn.php...ncept%20engine

Maximo

iTrader: (11)

what clutch are you using on it ? some clutches will start to fade out if they get warm, causing amotor to lose its bottom end snap ...

hobdog

iTrader: (19)

I am going to replace the front bearing. Do these engines come with a low budget front bearing? It seems strange for it to go bad that quickly. I am using the mugen stock clutch bell with mugen stock shoes, 1.0 mugen springs and avid revolution bearings. Are the tko's the best front bearings?

David Day

iTrader: (4)

TKOs, IMO, are the best bearings to get Just FYI

Loop&Roll

I doubt that the temp gun would be out by 20 degrees I use a fluke gun, most of the better guns should be within 2% accuracy. The problem is the person using the gun and where and how readings are taken, the gun is useful for the safety factor.