Carburetor for 2006 DRX 90 air cooled

[martybauer31]

Hi all, I have been looking all over, apologies if this has been answered (I'm sure it has) but I can't seem to find it.

I bought my son a 2006 air cooled 90 and it's looking like it's needing new filters and hoses and a carb kit as it appears to be leaking a bit. I can find filters and hoses, they are 1/4" correct? As for the carb kit, can't seem to find one anywhere, all DRR seems to have is a replacement carb, which leads me to my next question... I notice in my searching that some folks are using the Keihin PE 24 carbs, are these a straight swap or does anything else need to be done? And will these work with the automatic feeding of the oil, or would I need to start pre-mixing?

Thanks for your patience with the newbie questions, my son has really been enjoying this quad, just want to make sure I'm doing the right things!

Marty

[JoePA]

Marty,
I have an air cooled 90 engine that I picked up this past weekend and it has a 24 PWK carb. I don't think it's a Keihin but it works well. Jetting is 40 pilot and a 125 main. I didn't check what needle is in it but I have the clip worked best for me in the center position. As far as a straight swap...that I don't know as minet had a stage 6 intake that the carb fit into nicely. Not sure if it will fit into a stock intake but I don't see why not. Hope this helps as I'm new to the DRR world.

[martybauer31]

Thanks Joe! I ended up calling DRR, who referred me to Matt in Wisconsin, who funnily enough was getting ready to respond on this thread as well! :)

I was told that there really is no carb kit or anything that will help to fix these crappy little carbs, and that a replacement is the way to go. I will have to pre-mix, but that isn't the worse thing ever and Matt said the new carbs go in pretty easily. Waiting on a quote from him and I will update with my successes once complete!

[JoePA]

I think you can get away with a 24 OKO with the stock intake. You can pick up a brand new carb for $40-$50. There are a MILLION places that sell parts for these engines. Some of the stuff on the 90cc is different but most of it is universal.

[martybauer31]

So I got the new carb in, it seems to idle just fine, but it will big down and die when in full throttle going up hills and will also die going down the same hill when having to do lots of braking. Not sure what I need to adjust to get rid of the bog....

[chris p.]

see what size jets are in it and let us know.sounds like you're going to have to go up on both the pilot and main jets.also check where the mix screw is.

[martybauer31]

Thanks Chris, I will let you know when I get back up next weekend. I believe I got the 28mm Keihin carb from Matt, sent him a text and will hopefully talk with him tomorrow... A friend of mine also suggested looking at the position of the the throttle needle if that sounds right? He said that perhaps I need to move the needle down to lean the carb out a bit, anyone know if the needle for this carb has multiple settings available for it? The air/fuel mix screw is about 1.5 turns out at this point, performance did improve a bit, but my son still felt like he had less power going up hills and it stalled out quite a bit coming down. I had another friend suggest that I might need a hotter spark plug and ignition wiring kit if that makes any sense...

Sorry I don't have more info, my knowledge of carbs would fit into this post at the moment. :)

Thanks again for the help!

[martybauer31]

Just a small update and things for me to try when I get back to the quad next weekend. I talked with Matt and he recommended moving the needle down a position as it sounded to him like it was running a bit rich. He also suggested taking a look at the float height as well, it possibly needs to move down a bit.

I'll update next weekend, thanks for all your help!

[martybauer31]

So.... moved the needle down and it no longer stalls out, bonus! It's still having an issue being a bit short on power going up hills. Would that indicate possibly needing a smaller or larger jet size? We're at about 2600 feet if that makes a difference.

Thanks!

[chris p.]

pull the plug and see what color it is but it sounds like you have to go up on the pilot.the pilot controls idle to around half throttle or so.when we raced our drr 90 it had the malossi big bore kit and we ran a 28mm koso that was jetted at 145/45.on our 06 predator 90 that's air cooled we have a koso intake with a 24mm carb but it almost feels too big.it probably needs rejetting but it runs good and I can't recall what the jetting is.

[chris p.]

forgot to mention it but check out jetsrus.com. there's a lot of info there for altitude changes.usually you go down in size the higher you are.

[martybauer31]

The plug is black....

[chris p.]

it should be a tan/cream color.black is rich.too much fuel.

[martybauer31]

Roger that, do you think up a jet size or down? And just the pilot for issues with hill climbing?

Thanks!

[chris p.]

I would go down on the pilot 1 or 2 sizes at a time and see how it runs.don't make a lot of adjustments all at once. then check the plug again and make sure you use new plugs to get an accurate reading.ngk iridium are what we always used.you can also screw the air/fuel screw OUT to lean it a little bit and see if there's any change and if there is then you're headed in the right direction. you're also going to have to do a full throttle run to check the main too.don't do it on stands as it's going to need a load on it.also,have you checked the torque spring?? checked and cleaned the belt ??

[martybauer31]

I haven't checked the torque spring or the belt.... So, stupid me,I changed the needle position and then messed with the air/fuel mixture and got it cranking, thought I was done.... then noticed the damn choke was on... turned off the choke and leaned it all the way out and couldn't get it to run right at all. Does this confirm the need for the jet?

[martybauer31]

Another question, would I just switch out the pilot or the main jet as well? I was under the impression the pilot just covered the bottom 1/8 of the carb. Sorry for the probably simple question, just trying to learn something here as well.

That being said, I REALLY appreciate your responses to this point.

[chris p.]

with a new plug and the choke off this time (lol) get it going and try the air fuel screw and SLOWLY lean it out (turn screw out) and see what it does. if you notice a change you have to go down on the pilot jet.the pilot controls idle to a little more than half throttle so do one thing at a time.get it to idle first then see if your bog goes away and then move on to a full throttle run and check the plug again to see what the main needs.also,a weak torque spring on the rear pulley can mess with things a little so look into that as well.for a stock 90 with no mods you can do a stock replacement or possibly go to 1,500 rear spring.we use a 1,500 rear spring in ours but it has a lot of carb/clutch and pipe work.also,looking back at your posts you said you moved the needle clip down?? I believe that's going to add fuel so you might want to move the clip up from the original spot and go from there.if I remember correctly when you move it up it lets in less fuel and moving it down uses more fuel.it has to do with the needle traveling up and down in the jet.

[martybauer31]

So then, more evidence that I'm an idiot, I have been turning the screw in to try and lean it out a that is what seemed to work with the choke in the on position. I'll try turning the other way to see if that helps, but it just seemed to give me less power as I turned it that way when the choke was on....

[martybauer31]

So... turning the screw the correct direction did help a bit but it's clear that the jets need to be changed. Once I tear it apart, I'll figure out what I need and go from there, ugh.

[chris p.]

funny stuff !!!!!! it's usually the little things that bite us.as long as you're tearing it apart disassemble the entire carb and soak it in purple power or simple green for a few hours,rinse it off and blow out every passage with compressed air.before you put it back together spray the bowl gasket with wd-40 so it won't rip if you have to get back in there(and you know you will !!!).let me know the jetting too.

[martybauer31]

I'm happy to entertain! :) This carb is pretty clean, it's brand new, should I be cleaning the crap out of it anyways?

At any rate, I pulled off the carb and brought it home with me... The pilot is a 45, the main is a 122. My sparkplug is a BPR7HS.

On my main jets, it looks like I could go 120 or 118, and the pilot could go to a 42 or a 40. I realize you're saying just do the pilot first, but figured it couldn't hurt to have a main ready as well.

Also, it appears these jets are not Keihin jets, the carb is labeled PWK 28 and has a SunWorld stamp on it, the jets have a little half circle on them with a small triangle on the inside. Are these jets going to match up with the numbering for the Keihin jets? I notice that stock jetting for the Keihin is 38 for the pilot and 135 for the main.

Thanks!

[martybauer31]

Also, to address your comment on moving the needle... I tried it both ways, the needle was in the middle... I dropped the needle (moved the c-clip up one) and it ran a bit better, I then tried going the opposite direction to raise the needle (moved the c-clip down one) and it wouldn't even start for me. So at this point I will assume that dropping the needle leaned it out and I am heading in the right direction as it mentioned the direction for leaning at jetsrus.com. Great site by the way, thanks for the link.

Also, is that the best/quickest place to order jets? Hoping to get an order in tomorrow to take with me the following Tuesday, going to be on vacation and want to dial this in so me and my boy can go ride. :)

Thanks!

[wickestangwv]

Call Gary at G-Force he can get stuff out pretty quick

[chris p.]

cleaning a new carb probably isn't necessary but wouldn't hurt at this point.your 45 pilot sounds a little fat.rich is safe but not that much.your choice for mains sounds about right.just do the pilot first and then move on to the main.if you do both at once you might get lost in the tune.patience with this tune young jedi!!!! lol your going in the right direction with the needle clip so pilot is next.if it's responding to an adjustment then the pilot can't be that far off.can you post a pic of the carb and jets?? sunworld stuff can be a pain to find.

[martybauer31]

The carb just says 28 PWK on one side and has a small Sun World stamp on the other side.... I would take a pic of the needles, but I had to look under a lighted magnifier to even read the numbers on them. :) They look like standard Keihin jets from everything I have found on the net.

I went to the G-Force site and it looks like they sell the SunWorld carbs and the jets to go along with them. I sent them a note and hopefully I will hear back and confirm that I'm ordering the right stuff.

I have the one on this page:

http://www.g-forcepowersports.com/PWK-Carburetors-21---24---28---30---32mm-D-Slide-detail.htm?productId=-388292&browse=-42507&shopBy=-11348&catalogId=-3062

Thanks!

[chris p.]

28mm ???? I think that's a little too big for a stocker with no mods.if you posted the size earlier I didn't see it.my apologies.if you had a pipe and clutch work I think a 28 would be good but even with all of our Polaris 90 mods I think our 24mm is a little big but it might be jetting.i believe the stock carb was a 19mm sunworld and they were no good. you're going to have to use the stock intake somehow (different size inlets) because an aftermarket filter might give it too much air to tune.been there,done that.have you worked on it this week ?? the jets are pretty common and the numbers do vary and some even have no numbers. try raising the needle clip to the top position and see what happens. keep reading the plug !!!!!!!!!!!!!!!!!!!!!

[martybauer31]

I mentioned that's what I got on the first page... :) I haven't done any work on it since we left our cabin on Sunday... It's too late to get a different sized carb so I gotta keep going forward here, that being said, I got it tuned pretty close before I left. My son felt like he had the power back climbing and on the straights, there was a bit of bog still going downhill, but finally no more bogging out and dying.

I ordered the jets, they will be here soon hopefully, and I can put try them when I get back out there on my vacation next Tuesday. As far as raising the clip on the needle, that needle is staying where it is until I douse it in lighter fluid and torch the whole thing... I have never fought anything so much in my life, I literally needed 4 hands to get that stupid thing back together, and it wasn't a first try sort of thing. :)

Hopefully the pilot will do the trick, I bought a 42 and a 40 as well and a 120 and 118 main, so I'm hoping some combo there will finish this thing up.

[martybauer31]

Got my jets, I will be up at our cabin on Tuesday and will update after I get things installed and tested. Wish me luck!

[martybauer31]

Ok, got the 42 in and that seems to have helped, tuned the air screw, no stalls and he seems to have power up and down hills... fingers crossed but I think this might have done it!

[martybauer31]

Well, we had multiple successful outings over the week, so overall things look great! On a couple of occasions, he still stalled out going downhills, rare, but they happened nonetheless, anything else to try and tune?

Thanks again for your help!

[chris p.]

possibly the float level or bring the idle up a touch.