hmann1020

I was hoping some more experienced guys can help me here. I have a Shengqi 23cc 1/5 scale rc truck.yes, its the clone of the Firehammer. But, you can hardly go wrong at $275 NIB.

Anyway, after a couple of break in tanks of fuel, i started to really see what this truck would do. So, after about 20 mins straight of high speed driving through tall grass, the clutch started to slip to the point where I could barely drive the truck around above an idle speed. After taking the gearing area apart a couple of times and inspecting the clutch, I could see no real wear. Finally i put it all back together and it ran ok for a couple of minutes.

about a week later, when I went to really start driving it again, i got about 5 minutes into the run when the same issue sprang up. The clutch and bell got hot, and stopped gripping. The car is new, and the clutch has all its material on it.

After asking Duratrax tech support what they think (just told them I have the firehammer), Jack said that I have a "glazed" clutch / shoes. I have never heard of this, which is why I am here now!

Someone please explain a little better the concept of a glazed clutch, how to spot it, how to fix it, and how to prevent it!

I am wondering if the cheaper "clone" parts are the cause (crappy clutch shoe material) or crappy bell housing (thinking that is less of an issue, but again I am not sure)?
Please help! i cant stand to see the car sitting!

Also, one more side note, after fouling a spark plug after only 3 tanks, I am wondering if 25/1 gas ratio is too rich? I run a goped at 40/1 and i hardly ever foul plugs... and that engine has waaay more stress on it than the rc car. Thoughts? Comments?

savagecommander

dont ever run any less oil than 25:1- your motor will not last. if youre fouling plugs just sit down one day and iron out your tuning.

ive never heard of clutch shoes glazing. can you post pics?

hmann1020

yes, I will post pics later tonight if i can get around to it.

I have the car tuned pretty good on the high speed needle. any faster and I cant control it! maybe its the low speed that needs to be ironed out. I am assuming its the plug, because it was running, then it stopped. i cleaned the carb (full of dirt on the tiny inner screen), got it to fire again. it ran for a bit, the the clutch stopped working again, and the truck died. I could not get it started again. the plug was fairly wet when i pulled it. I am having a hard time finding this plug in any local stores
NGK CMR7H is a hard one to find for some reason. I would like to get an upgraded version, like one of the E3's...

as for the clutch, it Looks fine. it is fairly smooth though. I am not sure what it should look or feel like however.

cheezer1222

My Feedback: (3)

Maybe a vented clutch bell would help? It's nice to have, but I never ran into any issues with non vented bells. Maybe check to see if there is an excessive amount of friction/binding when you try rolling the car on the ground. Could be that the clutch is working too hard to move the car (that one's kind of a long shot).

mrfisse

The ****ty material on your budget clutch shoes has melted and become something that resembles glass. I.e very slippery. Buy a pair of high quality shoes instead and that should not happend again. Is your bell blue from exessive heat?
Ive heard about this issue to, though i have driven through terrain turning the clutchbell red and still nothing has been damaged. More than the bell turning blue that is. Then again i own an FG.

When it comes to you fouling plugs, this has nothing to do with your current fuel/oil ratio. Its fine like it is. Though you are running your carb to rich. Lean it out. And recheck your plug. There is loads of info on tuning your carb properly.

hmann1020

OK. Ifigured it does have something to do with that. the "rest" of the truck is "fine" so far however. Iput a new plug in, and had to clean the carb a couple of times. No idea how those tiny bits of debri get in, must be through the air filter while running through dirt. I have an extra fuel filter on the fuel line... So, the engine runs fine now.

I checked the clutch bell temp last night while rebuilding the carb. at idle, it sits at around 130 deg F. This seems high to me. I have suspicion that the clutch spring is also crap, and it has lost just enough of its tension to allow the shoes to slightly engage at idle speeds, further causing excessive wear on the shoes.

for the short term, i will sand the shoes and try to tune the idle as low a possible. To answer your question, no the bell is not blue in color, the inside is shiny metal color. the outside is still black. so, that piece is probably ok.

Instead of buying a vented clutch bell, has anyone every tried to drill some holes in the clutch bell? maybe 3 or 4 small ones to allow some of that heat to escape? $25 is a lot for a clutch bell that has just been cut up.

Finally, anyone had good experience with a certain clutch brand? Im a little weary of the 8k rpm clutches out there. What is the standard RPM of an idling 2 stroke engine?

savtraxx

just get a cy clutch with an 8K spring in it.
its not gona do anything to your car dude.

cheezer1222

My Feedback: (3)

I could be wrong, but I'm pretty sure that 8k is the number of rpms before the clutch engages. So a lower "k" clutch engages at lower rpms and a higher "k" clutch engages at higher rpms. Nothing really to do with idle.

hmann1020

yes. 8k springs are the rpms at which the clutch engages. that i am aware of. my concern with that, is that because you have to rev the engine that much higher to get the clutch to engage, you are essentially "popping'the clutch on it (something to that effect) therefore putting more strain on the rest of the drive train, axles and rims.

i was wondering what an engines idle rpm was so that i could gauge a spring from it.

do the CYclutches work on duratrax firehammer (since the shengqi is a clone of that)?
anyone have a site which has the best price to get it from?
Thanks for the help so far!

savagecommander

they should. i think DDM has the best price on a clutch.

hmann1020

just an FYI, i got an 8k clutch for the baja on ebay for 28$ shipped