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bulldogfallon
03-24-2007, 07:50 PM
I am having a problem with the 21mm OKO carb on my son's DRX50


Here is what it does:

Only starts with choke pulled up/on

When chokes is on and then turned off the rpms surge then it gradually lowers and then stumbles and dies.

If choke is left on then it idles great....

When the throttle is applied and let off quickly the rpms still maintain and then gradually reduces the rpms

I removed the air filter and I can see the slide returning to the bottom when I let off of the throttle, but the rpms still are not reducing.....

I ran some race gas in it the other day to see what kind of gain we would see....I drained the whole tank afterwards and went back to 93 octane..

Could this have caused an issue..

I have taken the carb apart and can see the choke valve moving up and down, so I don't know where to go from here


Anyone have some advice?

Nichols Atvs
03-24-2007, 08:35 PM
I take it was running good before you put in the race fuel . you may have fouled the plug put in a new one and try again also make sure you turn the pet cock back to on . or you colud have dirt in a jet

bulldogfallon
03-24-2007, 08:56 PM
I changed the jet out and used the air compressor to clean the carb out..

Could it be reeds?

I am not an expert on the carbs, but everything seems to be ok from what I could see..

The idle is erratic.....up real high and then it stabilizes and then just shuts down....but idles great with the choke on??


The part I can figure out is why the rpms don't drop when I let off the throttle....They do drop but slowly...

I have some carbs coming in on Tuesday, so worst case scenario I will put one of them on and see what happens

Nichols Atvs
03-24-2007, 09:00 PM
Did it run good before the rsace fuel

bulldogfallon
03-24-2007, 09:28 PM
Before and after the race fuel


Check the reeds ..they are good


I'll take another run at the carb...

Steven623
03-24-2007, 09:53 PM
Hi, What size jet is in it? Any change in weather? Also, did he ride it long or did it happen pretty soon after?

bulldogfallon
03-24-2007, 10:09 PM
The boot between the carb and the intake manifold is the problem...

I guess from me tightening the clamp the twisting caused it to separate

I will replace it and post the results back...

bulldogfallon
03-24-2007, 10:29 PM
All better!!!

Took the boot off the 90 that I have sitting in my living room :)

Purring like a kitten again!!

Poor carb got all violated and cursed at and it was innocent of all charges!! LOL


The tear in the boot was on the top part so when you look straight at it and felt the face of it ..it seemed ok....

The 07s with the 21/24mm OKO carbs and koso style intake manifold have a boot and the intake manifold...the 06 just has the carb and a rubber boot....

Now I will be able to sleep tonight!!

Off to the track tomorrow

Thanks for the help guys!!

riding4fun
03-25-2007, 08:15 AM
Originally posted by bulldogfallon
All better!!!

Took the boot off the 90 that I have sitting in my living room :)

Purring like a kitten again!!

Poor carb got all violated and cursed at and it was innocent of all charges!! LOL


The tear in the boot was on the top part so when you look straight at it and felt the face of it ..it seemed ok....

The 07s with the 21/24mm OKO carbs and koso style intake manifold have a boot and the intake manifold...the 06 just has the carb and a rubber boot....

Now I will be able to sleep tonight!!

Off to the track tomorrow

Thanks for the help guys!!

In the living room? Dang you are into this stuff. I thought I was being nice when I let my dogs in the living room.
hA HA HA.

Darrell

riding4fun
04-28-2007, 05:59 PM
Originally posted by bulldogfallon
All better!!!

Took the boot off the 90 that I have sitting in my living room :)

Purring like a kitten again!!

Poor carb got all violated and cursed at and it was innocent of all charges!! LOL


The tear in the boot was on the top part so when you look straight at it and felt the face of it ..it seemed ok....

The 07s with the 21/24mm OKO carbs and koso style intake manifold have a boot and the intake manifold...the 06 just has the carb and a rubber boot....

Now I will be able to sleep tonight!!

Off to the track tomorrow

Thanks for the help guys!!

I have the same exact problem. Did you just replace the stock rubber boot or is there an aftermarket boot that will work better?

Thanks,

Darrell