250-500cc WR360 Carby Issues

Lads,

I'm having carby issues with my 02 WR360. Now i've read the forums and have recognised that Mikuni are shit and its recommended to change it out for Keihin PWK. Now as money is tight i've been trying to source a 2nd hand one off ebay etc but its hard to recognise what Keihin will actually suit the WR. For example will a 1998 KTM380 Keihin suit or will an 2003 YZ250 carb suit. All these are available on ebay at the moment. Now in australia a new carb is $400 so i'm trying to get out of it for around half that. Any advice you blokes can give me will be greatly appreciated.

Mick

Check with Motorsportz here in the forum.
I think he has the best price on PWK and JD jetting kit are already in.
The best value/time saving...

Try here. They deliver overnight
http://www.jdk.com.au/
I have the exact same bike as you & don't have any issues with the carb. Found a good cheap mechanic to & only charges $30.00 per hour & he lives in Prospect

Croc,

So you've persisted with the mikuni and aren't having any problems. My bike only has 2270km's on it and it's been nothing but drama since i bought it 16 monthe ago. I just can't rely on it to get me out of the bush hence me not riding it much. Do you reckon i should talk to the boys from jdk and see what they reckon. Is this mechanic your talking about is he connected to jdk also.

Guys,

I found a PWK 39 mm from an early year KTM. It takes all the headaches away from the bike. I am sure an airstriker 38mm would be even better but the 360 has such a large vacuum pressure that the 39 works flawlessly. My jetting is for high altitudes so it really doesn't translate to sea level but if the 39mm works from 4000-10000' where the air and pressures are much less it will certainly work for you guys at sea level. Frankly any PWK 38 or 39 mm will work.

Walt

The only problem I have had with mine was idling. There is not much adjustment on the screw, but its heaps better now. The mechanic thinks i am running my oil a little high, so I am changing my ratio. JDK are in Coffs Harbour. They guy i am going to is near Blacktown. I am picking my bike up tonight. Cost me $200.00 for Piston,rings & top end bearing to be done as well as wheel bearing,brakes & a few other things. Very cheap i thought. I would do it myself, but don't have time.

Croc...it's got nothing to do with fuel ratio in regards to idling.
Adjustment on the screw..is that the idle or the air screw?
Wallybean knows his shit and is/has been helpful to me in other forums (check thumpernet) in the PWK area. Essential, any 38 or 39 PWK will work, shit even a 36mm would do the trick but you need to make sure it isn't the TPS version.
Also, grab a JD Jetting kit for a Keihin (give mainjet a call in Melb) or other types of needles, range of pilot jets, BR8ES sparkies and go testing from low to mid, mid to WOT and WOT - heaps of info on how to do plug chops and reading spark lugs.
Before you start all this, make sure you aren't leaking from the base gasket or top gasket etc as an air leak causes low down splutter plug flowing.

As Walt said, once sorted it's adjust the air screw and ride.

Croc,

Can you put me onto this guy maybe a phone number.He sounds to good to be true. I was running at 40:1 but have gone out to 50:1 considering goin out to 60:1. The mechanic at R & D Husky at Emu Plains said 50:1 no worries with the oils being so good these days. I was running Motul but now use Motorex.

I spoke to JDK they can do me a Keihin PWK off a Ktm 300 for $275.00 + freight. I still reckon i can get one a bit cheaper.

Yeah I know, I should have said that he thought it was a little smoky, So I am adjusting my ratio to lean the oil fuel mixture.
Yeah its the idle screw
Mine runs well, heaps of power & torque, only thing is that it can be savage up top.....But its a big bore 2 stroke. I not that worried about it, as its a transition bike, there is a new WR300 just around the corner. Just need to gather about another 3-4 grand & I am straight out to R&D to pick one up

Croc,

The number of the mechanic in Prospect you using. Is it possible to get his number off you.

Will put his number up later.I am changing to a ratio of 60:1

Sorry blokes l'm got confused on who has a problem with what

123.Mick75, the only problem with the TMX 38mm is that they are very sensitive carb's so they require quite a lot of adjusting for the conditions you ride in. Even with WR300's, guys are going to Keihin PWK's because they aren't so sensitive to environmental change as compared to Mikuni meaning guys can tune them in easier plus there is a wide range of needle/slides and jets available - don't get me wrong, a well tuned TMX is as good as a well tune PWK.

Either you start to understand the whole science of jetting and how it effects your bike rather than the ratio of premix and keep the TMX or go down the Keihin path, still understand jetting but then set it right and just adjust the air screw to compensate in air density due to elevation changes or change the clip height but that's about it unless you move to Victoria or Tasmania

Hope it helps.

Doug Ward 0401980439

ohmygewd,

Thanks for the advice but the mikuni seems to be nothing but trouble. I've had it to so many different mechanics to try and sort it even bit the bullet and took it out to R & D Husky which is a massive mission on my behalf thinking a Husky dealsership should be able to sort it and i took it up to the Watagans and got about 70km's out of it and it come to a burbling stop. Now forgive my lack of carby knowledge but i just need it to be reliable and the Keihin sounds like it will solve the issue somewhat easier than persisting with the mikuni. Now i've had the carby apart and cleaned it thoroughly and it will start up but once you had some throttle it just bogs down and fouls plugs. I haven't touched any jets or air/fule mixture screws and seeing I'm out of the watagans and at sea level you think it should run but it doesn't. I'm scared to take it out into the bush for the fear of having to push it out of hill rocky areas when the bastard stops on me again. Seriuosly considering fixing it and selling it.

Croc,

Thanks Croc for that number I reckon i'll give the lad a go.

Mick,

PM'd ya and also try pulling the carb out of your other bike (even if you have to pull the whole thottle tube off if the 360 cable doesn't fit), open it up and write down the jet sizes and install it on the 360 and see how that runs?

NOTE TM and TMX uses the same jets and needles and slides from memory.

ohmygewd,

Pull the carb out of the 250 you reckon. Mate i have to thank you for your input into helping me out it's been greatly appreciated. I'm just gonna bite the bullet i reckon and try and track down a 2nd Hand Keihin. Hopefully someone around Sydney will have something at a reasonable price.

Mick.

Mick,

The TM uses a different pilot than the TMX. The tip size on the TM is smaller. If you try putting the pilot from the TMX in the TM it will wad up the end.

Walt

I thought they were the same Walt..then again l'm a Keihin boy

Mick, pull the carb off the Wr250, you can't do no harm as the 250 carb is working quite fine so pull it off, write down all the settings, go out buy a few leaner pilot jets (just focus on 1/8 to 1/2 throttle) and see or feel how you go.

As far as Keihin, if you can get a 36-39mm PWK or even a PJ (choke is part of the idle circuit which can be a PITA for idle adjustments), then l think you'll enjoy riding the Wr360...can't stress enough to learn carb tuning and jetting, at least an idea

Good luck,

Jay