Drr 50 mech help needed bad

[kd228]

I have a 2 air cooled DRX 50's. One is a 07' and the other is an 06'. The 07 is geared 18 - 32 and is very loud but seems to go nowhere especially up steep hills. When my son races tracks like Budds Creek, when he gets to the top of the hill he barely makes it over. But the bike is screaming very loud. I've put in clutch springs and a new national front and rear clutch kit and same problem.
On the 06', the bike goes fast. It is geared 19 - 35. The problem I'm having with this one is that in the power band it is great but even full throttle it will bog down and then rev back up. Sometimes when you press the throttle it bogs and then goes. Again it goes down out of the powerband and you have to let completely off the throttle for it to pick back up. My son is 5 and a very good racer and I am holding his ability back with not being able to fix his bike. If you have any idea of the problem, please help.

[Bryar Riley]

check the air screw on the 06 if you have a uni filter it don't need to be out very far at all......had same problem turned it all the way in and about 1.5 turns did the trick.......i have a magic screwdriver if you need it.....LOL......thats what the man told me that fixed mine.........................

[neveready]

This sounds like clutching issues. One sounds to have too light of rollers and the other too heavy? Could maybe have some belt slippage. The national front and rear clucth is not a direct bolt on for every 50. you can take two out of the box and never set them up the same. Do they have the same carb? We have struggled with getting these setup but have a few ideas that work really well. there are many options and good advice on this forum.PM me if you don't find any other advice and want me to look into this issue a little deeper for you.

[riding4fun]

It does sound like clutching.

The problem you described with taking off and wide open throttle sound like the main jet could be too big. If you are running good in the mid but it bogs while full throttle and then you let the gas off a little it begins to run good again. I have experienced that while trying to tune. Don't know if that is the problem but something to look into.

[dblacks]

Originally posted by neveready
This sounds like clutching issues. One sounds to have too light of rollers and the other too heavy? Could maybe have some belt slippage. The national front and rear clucth is not a direct bolt on for every 50. you can take two out of the box and never set them up the same. Do they have the same carb? We have struggled with getting these setup but have a few ideas that work really well. there are many options and good advice on this forum.PM me if you don't find any other advice and want me to look into this issue a little deeper for you.

ditto, Too light on the one that sounds loud and too heavy on the other one

[bulldogfallon]

Originally posted by kd228
I have a 2 air cooled DRX 50's. One is a 07' and the other is an 06'. The 07 is geared 18 - 32 and is very loud but seems to go nowhere especially up steep hills. When my son races tracks like Budds Creek, when he gets to the top of the hill he barely makes it over. But the bike is screaming very loud. I've put in clutch springs and a new national front and rear clutch kit and same problem.
On the 06', the bike goes fast. It is geared 19 - 35. The problem I'm having with this one is that in the power band it is great but even full throttle it will bog down and then rev back up. Sometimes when you press the throttle it bogs and then goes. Again it goes down out of the powerband and you have to let completely off the throttle for it to pick back up. My son is 5 and a very good racer and I am holding his ability back with not being able to fix his bike. If you have any idea of the problem, please help.


What is a National Clutch Kit? Fancy name, but what does it consist of?

To make an assement and recomendation we would need to knwo exactly what you are using in your CVT set up...Guessing will not help you fix your problem quickly or cost effectively.

Let's see what you are using and see how they relates to the symptoms.

Can you provide the CVT info: Roller weight, Torque and clutch Spring(s) strength and brand, brand variator and clutch, belt size and type.

Also you carb info: Brand, Sizing and jetting (at least main jet), air screw setting, typpe of air filter

Also--When the last time any of these items have been freshened up.


You have symptons that seem to be CVT and jetting related.....