facebook1 youtube1 twitter1 instagram linkedin1 pinterest1

NOTICE:  If you are not a free registered member of the site, you will not see the photos in the forum, and you won't be able to access our premium member content. Please consider joining our community! REGISTER AND MAKE THIS BOX DISAPPEAR!

×

Pictures Posting Not Working (12 Jun 2023)

Picture uploads is again unavailable. We are working on the problem. Thanks for your patience.

Makotosun

Keihin 35mm PWK is a great fit on the DT360

  • turbodan
  • turbodan's Avatar Topic Author
  • Offline
  • Site Supporter
  • Site Supporter
  • Posts: 423
  • Likes received: 346
I've had enough fun trying to fix the stock carb on this 360. Runs lean at a cruise, not very responsive to jetting changes. Ive tried different combinations of pilot, needle and air screw setting to no avail. If you didnt know what detonation sounds like you would surely burn a hole right through the piston.

The Keihin is used on many higher performance two strokes since the 90s. The 35mm uses a smaller body than the 36 and 38mm PWK which makes it a fine candidate to plug into the stock DT360 intake boot.

Jetting is a fairly simple affair. I threw a N1AL needle in from the box-o-jets, a 158 main and a 42 pilot. This started and ran, though clearly rich. A 38 pilot runs properly crisp and a 148 main is a lot better at WOT, though still rich. A 145 would probably be best.

Power is significantly improved, despite the stock pipe still firmly corking this motor up. Much more power especially in the 4-6k range. Best yet, it cruises at any speed without any detonation, far better than the stock carb and near constant pinging.
The following user(s) Liked this Post: Rick C., MarkT, Bigdog302, FrankC, RT325, mdscott, KJB, shyted, Snglsmkr, nhsteve, Von, Pedalcrazy, RustiePyles
Last edit: 26 Aug 2020 15:29 by turbodan.
26 Aug 2020 15:26 #1

This message has an attachment image.
Please log in or register to see it.

Please Log in or Create an account to join the conversation.

  • Posts: 9639
  • Likes received: 3915
Good info to have out there thanks. I had one off a reasonably late KX125 on my old rat bike RT2, since sold but still doing VMX with it on. Wasn't the shallow bowl carb though & i thought it was a 36mm. Anyway--worked great after a bit of jetting. Expand the pic up & i'm sure its this bike.

Attachment not found

The following user(s) Liked this Post: MarkT, turbodan
Last edit: 26 Aug 2020 16:58 by RT325.
26 Aug 2020 16:54 #2

This message has an attachment image.
Please log in or register to see it.

Please Log in or Create an account to join the conversation.

  • Posts: 215
  • Likes received: 141

Replied by Snglsmkr on topic Keihin 35mm PWK is a great fit on the DT360

Thanks for sharing your pioneering experience with a flat (non-round) slide carb with us.

If I'm not mistaken, this may be the first post for this type of conversion that has been followed through with.

Good to know this carb body will clear the exhaust without "creating" clearance.

I'm interested in a follow up if you dial in the jetting even more.
26 Aug 2020 17:06 #3

Please Log in or Create an account to join the conversation.

  • turbodan
  • turbodan's Avatar Topic Author
  • Offline
  • Site Supporter
  • Site Supporter
  • Posts: 423
  • Likes received: 346

Replied by turbodan on topic Keihin 35mm PWK is a great fit on the DT360

This one has an aftermarket bowl on it so it looks a little different than the standard PWK. You get what you get off of ebay.

The KX125 used either a 35, 36 or 38mm carb depending on the year, not many of them had the 35. An easier procurement is a carb from a 95-06 KDX200. This is the same carb. The 36/38 are somewhat larger in overall size and the inlet/outlet clamp diameters are larger too. The 35mm carb is a better fit on the DT.

I have larger jets and smaller jets but no 145 so I'll order one up. What I'm really looking forward to is installing the MX360 pipe I have here. That will require a little welding to fit the DT and follow the stock routing but with the larger carb I expect a noticeable boost.
The following user(s) Liked this Post: Hammer, FrankC, RT325, Snglsmkr, nhsteve
26 Aug 2020 17:53 #4

Please Log in or Create an account to join the conversation.

  • Posts: 200
  • Likes received: 274

Replied by akara1 on topic Keihin 35mm PWK is a great fit on the DT360

I recently just threw a 32mm OKO carb on my dt360 for 35$ shipped i was like why not.
Its a powerjet carb so the main doesnt have to be as large i think, running 140 main and 41 pilot it came with.
Seems to run well but ive only gone up and down the road once with it so far so will report back with any jetting changes I make!
I slipped a little slilcone couple over it to get it to work on the stock airbox.
The following user(s) Liked this Post: Snglsmkr
Last edit: 26 Aug 2020 21:27 by akara1.
26 Aug 2020 21:25 #5

This message has an attachment image.
Please log in or register to see it.

Please Log in or Create an account to join the conversation.

  • Posts: 223
  • Likes received: 197

Replied by Delcowizzid on topic Keihin 35mm PWK is a great fit on the DT360

My pwk35 of a kx125 k4 runs mint on my 78 dt250 got it dialed in good could do with a leaner needle I'm on the top groove any lower clip position Is far too rich
The following user(s) Liked this Post: FrankC, Snglsmkr, Von
27 Aug 2020 03:47 #6

Please Log in or Create an account to join the conversation.

  • Posts: 215
  • Likes received: 141

Replied by Snglsmkr on topic Keihin 35mm PWK is a great fit on the DT360

Turbodan, are you running with the oil injection?

I'm curious of whether there were any mods required to get the carb and injection pump aligned due to any difference in carb slide stroke.
27 Aug 2020 05:00 #7

Please Log in or Create an account to join the conversation.

  • Posts: 1052
  • Likes received: 662

Replied by shyted on topic Keihin 35mm PWK is a great fit on the DT360

Yes The PWK is good for the most of it.
There's one on my GasGas and it's miles better than the standard Delorto carb.
The action is very light due to the flat slide and the response makes my bike launch up rocks like they're not there.
Good choice and that would probably be a good carb to fit to a DT 400 . I read people have running problems with them as they run very lumpy and are hard to jet.
Great info .
Regards Ted.
27 Aug 2020 11:51 #8

Please Log in or Create an account to join the conversation.

  • turbodan
  • turbodan's Avatar Topic Author
  • Offline
  • Site Supporter
  • Site Supporter
  • Posts: 423
  • Likes received: 346

Replied by turbodan on topic Keihin 35mm PWK is a great fit on the DT360


Yes, still oil injected. It is currently adjusted with the injection pump at the factory mark with the throttle closed. At full throttle it cranks the injection pump past it's original wide open position. I don't know if this has any effect on oil delivery. I hope not, it was already over lubed in my opinion.
27 Aug 2020 14:01 #9

Please Log in or Create an account to join the conversation.

  • Posts: 215
  • Likes received: 141

Replied by Snglsmkr on topic Keihin 35mm PWK is a great fit on the DT360

Good to know that you are running the pump.

I believe the rotating ramp on the pump cam (that aggressively limits the pump stroke at idle) is pretty much flatlined at WOT and likely at some point before that.

Thanks for the detail.
27 Aug 2020 17:23 #10

Please Log in or Create an account to join the conversation.

Moderators: yamadminMakotosunDEETVinnieJames Hart