DRX 50 jetting help

[9sec.Bird]

Quad is stock other than a uni filter and outer wear bolted right to the carb.

I went from a 105 jet to a 120 in the main, seems a little rich at wide open.

It is hard to start now and off idle it doesnt run very good.

Do I need to move the needle?
is there a pilot jet to change?


Thanks for any help, Wayne

[hotquads1]

Hi Wayne ,
which carb do have ? and what year is the 50? There are several variables , fuel?, altitude ?, temp?, you should not have to increase the that much for just the air filter change. I can talk you thru the jetting , if you like you may call me at 334-705-0084
marc

[9sec.Bird]

Originally posted by hotquads1
Hi Wayne ,
which carb do have ? and what year is the 50? There are several variables , fuel?, altitude ?, temp?, you should not have to increase the that much for just the air filter change. I can talk you thru the jetting , if you like you may call me at 334-705-0084
marc

I bought it March 2006 Not sure if its an 05' or 06'

93 octane
roughly 1,000' above sea level (maryland)
50-70*

Thanks for the help Marc.

[kenjolly]

I would try the 105 again , put the clip on the needle in the middle and try a 38 pilot. that should give you a good starting point.

I never ran more than a 95 main, but i like'em lean.

good luck , post you results and we can help you more.

[bulldogfallon]

Sounds like it must be the Mikuni carb due to the year of the quad.

They are very sensitive to the adjustement of the air screw on the front of the carb.

Have you tried adjusting the setting at all?

We run a 105 here at sea level so a 115 may not be too far off.

Would it be possible for you to install a new plus and clean out the air filter and see if you can get some good plug readings.

Is your choke partially on? (pull the lever a few times to make sure it is not stuck)

On the take off is it the engine not running well or could it be linked to the CVT tranny?

Can you describe the issue with more details?

What changed before you noticed the difference in how it runs?

[DRRKID]

well the year of the 50 would help for shure,the pilot jet is all i change on my 90 i run a 15,but i also dont know because i do not have a 50 ,listen to hotquads,he has a drr shop in alabama,good luck

[hotquads1]

bulldog is correct your quad should have come with a 16mm mikuni, and the 120 is to rich , go back to the 105 and drop the needle clip to lowest groove . but my concern is compression , your hard starting would not be due to rich condition, before you spend any time tuning check the compression , also report which pilot jet is in the carb
marc

[9sec.Bird]

Originally posted by hotquads1
bulldog is correct your quad should have come with a 16mm mikuni, and the 120 is to rich , go back to the 105 and drop the needle clip to lowest groove . but my concern is compression , your hard starting would not be due to rich condition, before you spend any time tuning check the compression , also report which pilot jet is in the carb
marc

I never tried the 105, I just assumed it needed to be richer because I took the long pipe and stock filter off and put the uni filter right on the carb.
I'll put the 105 back in, I should have known that they leave them rich from the factory.

It started fine before I did the fiter and jet change.
I'll change it back to the 105 and move the needle clip and let you guys know how that does.

Thanks alot! :D