Finally got one!

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, and others.
PortCityRC said:
What about his reed Z?
Click to expand...
Cant say as I don't really know what a rcmax reed is supposed to look like, nothing really jumps out to me though. I say new carb and gaskets, plug , then go from there (unless he has already tried that, I didnt check, sorry I'm on vacation lol). If not then idk, maybe the ignition is faulty. Calling @Seandonato73
 
RcJunkie13 said:
Ok here’s what I am wondering, even the rpms shown in the vid, should the clutch not be engaging, kinda makes me still think it’s transmission, unless the clutch arm is slipping on the crank or something like that
Click to expand...
Tranny is good. Clutch looked fine but maybe something else is wrong with it. Probably have to take the clutch apart and reassemble it. This clutch is pretty bullet proof as it is.

When the car is running and not on the ground the wheels do move but I have to rev it pretty hard.

Let's say the clutch was slipping or something is bad in the clutch system but doesn't explain why the car is running so rich?
PortCityRC said:
True..ignition that could be the case...he said it sounded like it 2 stepped so we all thought clutch
Click to expand...
A faulty ignition makes the car run rich??
 
niz55 said:
Tranny is good. Clutch looked fine but maybe something else is wrong with it. Probably have to take the clutch apart and reassemble it. This clutch is pretty bullet proof as it is.

When the car is running and not on the ground the wheels do move but I have to rev it pretty hard.

Let's say the clutch was slipping or something is bad in the clutch system but doesn't explain why the car is running so rich?

A faulty ignition makes the car run rich??
Click to expand...
It could if you were giving it full throttle and no there's no ignition to burn that extra fuel being dumped in there
 
Could be a faulty carb, I've had 2 issues with the wj71 carbs. Both my issues were them running stupid rich and just dumping fuel in even at idle.

Make sure your adjusting the right needle for your high/low. It's good to get a back up carb also. Do you have a running vid or did I miss it?
 
John Parks said:
Could be a faulty carb, I've had 2 issues with the wj71 carbs. Both my issues were them running stupid rich and just dumping fuel in even at idle.

Make sure your adjusting the right needle for your high/low. It's good to get a back up carb also. Do you have a running vid or did I miss it?
Click to expand...
He does have a vid👆back a little..and I believe he's running the rooster tail 990 mod John
On the 65 supreme
 
There's nothing wrong with that engine internally. I still vote carb issue, kinda hard to judge diaphragms in the pictures, but nothing is screaming I'm junk. I would bet it's a needle/seat and or pop pressure issue. Do you have a way to pressurize the carb to check pop off pressure? It's pretty easy to do, and you have the carb apart already.
 
Seandonato73 said:
There's nothing wrong with that engine internally. I still vote carb issue, kinda hard to judge diaphragms in the pictures, but nothing is screaming I'm junk. I would bet it's a needle/seat and or pop pressure issue. Do you have a way to pressurize the carb to check pop off pressure? It's pretty easy to do, and you have the carb apart already.
Click to expand...
I am reading and learning about the internal of these carbs and might be the damn carb.

Honestly if it is the carb rcmax should cover it and send me another 990RT but I see that rooster tail also has a 1107RT so I might even go that rout as i had always used 1107 in my previous motors and never had issue and very easy to tune.
 
niz55 said:
I am reading and learning about the internal of these carbs and might be the damn carb.

Honestly if it is the carb rcmax should cover it and send me another 990RT but I see that rooster tail also has a 1107RT so I might even go that rout as i had always used 1107 in my previous motors and never had issue and very easy to tune.
Click to expand...
maybe ask rcmax if instead of sending another 990 you can have a 1107
 
The 1107 will need the fueling upgrades done to it to handle the requirements of that engine (I would think) but nevertheless I would go back to rc max and see if they would send you a new carb. Its practically a new engine and you shouldn't be having carb issues this early in the game.
 
Going to try the pop pressure test and see what I get.

I made this thing as I don't have a manual pump. I will set the regulator all the way down and gradually increase till it pops.

PXL_20210622_190715104.webp
 
Did I do this correct?
Started to leak @ 21psi
Popped @35
closed back up @19psi

 
I know they offer the service (blue print) but not sure how much they charge. I might try to do it myself.
 
Last edited:
I was gonna comment on that last night, but didn't want to sound like I was bashing rc max.... I gotta go make that video for you quick..
RcJunkie13 said:
not that i am doubting you or anything... but are you sure???
Click to expand...
Don't worry if he screws it up it's his money that had to fix it, not his daddy's
 
RcJunkie13 said:
not that i am doubting you or anything... but are you sure???
Click to expand...

Gotta try it. If it goes bad than I am out $200 but it will be a good learning experience.
Seandonato73 said:
I was gonna comment on that last night, but didn't want to sound like I was bashing rc max.... I gotta go make that video for you quick..

Don't worry if he screws it up it's his money that had to fix it, not his daddy's
Click to expand...
I even called Doug at esp because he does a amazing porting and cleaning job. But he doesn't have time as he is really busy on the regular zenoah.
 
Last edited:
Back
Top