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-   -   Another happy TM36-68 install on stock bore (https://www.kawasakiforums.com/forum/klx-250s-71/another-happy-tm36-68-install-stock-bore-41373/)

durielk 01-07-2014 10:29 PM

If you need rim locks...
I put 2 on the rear (@ 180 degrees) so you can balance the tire, if you take it on the road.
I put 2 on the front as the torque on the front is much larger if you hit the brakes than anything the rear will ever see, 2 if you want to balance it for the road.

Klxster 01-08-2014 12:43 AM

It's the accelerator pump that your feeling - a hard hit of power anytime you nail the throttle while cruising up to about 3/4 throttle - depending on how you've adjusted the pump. I take it you've never ridden a modern 4 stroke off road bike. BTW, you can now flood your bike during starting with that pumper carb...when you do, every twist makes it worse. You have to just sit there with it wide open for awhile before I'll start.

Thank you for this thread. I'm sure I'm not the only one eager to hear about the performance enhancement that carb offers.

TNC 01-08-2014 03:00 AM


Originally Posted by Richard Avatar (Post 505035)
I wonder how much the accelerator pump is actually contributing vs just getting rid of the CV carb with its inherent lag?

The accel pump spray isn't that intense and as far I know it works only when the throttle position changes rather than a constant stream in between its starting and stopping point.

If so, then once you wick it open to certain point it's all done squirting until you open the throttle more.


In any case I'll take the huge improvement in power :)


After installing the pumper carb the other day, I went out on the hard-packed dirt road nearby to do a quick test...the bike just roared and shot forward in each direction. The next day I came out to a flat in the rear that wouldn't accept any air. Sure enough the valve stem had been slightly torn away from the tube!

There wasn't that much traction to be had on that stretch; maybe the problem was more having slightly low tire pressure already combined with might be an inferior imported tube that allowed the tire to spin on the rim but I've ordered a bead lock just in case I need it.

The pump's spray doesn't have to and really shouldn't be intense. It takes very little additional fuel to provide a real improvement in engine response. And in the bigger picture between the OEM CV carb and the pumper, look at the efficient carb throat design of the pumper. And instead of a throttle plate opening on the CV carb, which in turn has to rely on vacuum to pull the slide up, with its inherent friction, the pumper has a direct mechanical link to pull the slide up. Actually it's fairly impressive that they can get a CV carb to work as well as it does, but it still doesn't hold a candle to a well tuned quality pumper.

Richard Avatar 01-08-2014 04:32 AM

I did put the 15 pilot jet back in it and it's much crisper now. The 17.5pj sounded a little fat.


I'll have to try some plug chops on a clean plug. I think the 130mj is off a tad one way or the other. There's no missing or sputtering etc at WOT but it doesn't seem to want rev up the limiter cut off.

It seemed to want to rev higher before the carb swap, so maybe up or down a size on the main jet

The old plug was a beautiful tan on the porcelain, but it might be masking the jetting effects with this new carb

Mid range seems excellent and pulls very hard

Richard Avatar 01-08-2014 08:08 AM


Originally Posted by Klxster (Post 505043)
It's the accelerator pump that your feeling - a hard hit of power anytime you nail the throttle while cruising up to about 3/4 throttle - depending on how you've adjusted the pump. I take it you've never ridden a modern 4 stroke off road bike. BTW, you can now flood your bike during starting with that pumper carb...when you do, every twist makes it worse. You have to just sit there with it wide open for awhile before I'll start.

Thank you for this thread. I'm sure I'm not the only one eager to hear about the performance enhancement that carb offers.

It was cold starting (+70 deg ambient) without the choke pretty good with the 17.5.. I think I heard some protest from inside the cylinder when I tried to add some choke right after it started.

Tomorrow I'll see how the 15pj does on a cold start.

I worry more about some yahoo walking up and twisting the throttle while it's parked :eek:


Other than this 2009 XR200 I also have here which is still decades old technology being sold here in the Philippines, my last on/off bike was a late 80's XT600

I was busy with cars and road bikes :)

Richard Avatar 01-15-2014 03:42 AM

Well, I'll probably go ahead and try the 40mm pumper after I get the 331 kit installed :eek:


Afterall, there are 40mm carb kits for 1200cc street bikes with 300cc/cylinder, and this 250 isn't balking at the 36mm one bit.

I know the larger venturi will require different jetting than what's on my TM36 now (can't recall what's in there right now other than the 15pj, and 130mj)


Anyway, I'm wondering about jetting that bigger carb. Would it be better to start off with the same jetting as what's in the TM36 and make adjustments, or just start with the TM40 standard jetting?

Standard TM40 jetting is near the bottom of this page:

http://www.ebay.com/itm/Mikuni-TM-40...-/151136836676



So if anyone wants to venture a guess...

:D

Richard Avatar 01-26-2014 08:00 AM

After waiting out 2 weeks of rain and inclement weather, the skies have cleared so I turned on the petcock/pulled the choke and after giving it a few seconds to fill the carb fuel bowl, the bike started right up nicely on full choke- and settled into a steady idle.

So for me at least the 15pj seems to be the ticket

Doing a WOT plug chop, the insulator on the new plug still looked brand new, so I raised to the mj to 132.5; the bike felt better at WOT and showed a little color. If I remove the oversize float bowl plug, then remove long the idle screw (after measuring how far it sticks out of the carb) I can change main jet by rotating the carb. Much easier than removing the hole dang thing!

So I left it there for now, preferring to spend more time riding it for a few days before trying the 135. - Which is the biggest mj I had sent over here

I'm getting some sort of slight hiccup now and then at low speed steady throttle while cruising, but it's not fouling the plug or causing any probs otherwise. Not worth trying to fix it would seem.



Guess I'll want to order some larger main jets in case the 331 kit wants more fuel, and I can use them with the 40mm pumper I'll be trying

There's so much low end with this 36mm pumper that I don't see 331cc falling on its face with a 40mm - at least not with this 14/47 gearing

:)

Richard Avatar 01-26-2014 05:40 PM

Btw, I threaded my throttle cable into the TM36 carb bracket once - the next time I had to take the carb off I drilled the hole in the bracket out a size larger so the threaded cable end would just slip in and out of it and use the two nuts on either side to secure the throttle cable in position

:cool:

IDRIDR 01-26-2014 10:09 PM

Good thread Richard. I linked it up in here: https://www.kawasakiforums.com/forum...q-links-30733/

dpippin 02-22-2014 05:56 PM

2 Attachment(s)

Originally Posted by Richard Avatar (Post 505021)
Fiddling with my pull throttle cable today, I tried just about every routing variation but the cable was still was too tight as the bars swung to the left

Turning the throttle housing upside down so the cables exited below the bar though gave me the extra length I needed with some to spare!


The idle speed adjust screw comes very close to the rectifier(?) mounted on the frame. But that white plastic knob pulls right off and still leaves a slotted screw head to allow adjustments with a screw driver

Odd the TM36 comes with that long float bowl drain plug, where the TM40 uses the shorter drain plug... Yet the internal jetting is the same series for both carbs

It would have bend nice if Mikuni would have added a drain screw to the float bowl


;)

I had the same problem on my 2007 KLX250 so I ground a little of of two fins on the rectifier.

Attachment 9769

That long drain plug prevents me from rotating the carb to make changes.
It hits the starter on one side and the Kreiger cam chain adjuster on the other side.

http://i292.photobucket.com/albums/m...pse7fae732.jpg


So I ground some of the material of the drain plug to gain a little more clearance
Attachment 9770

I wonder if the shorter drain plug from the TM40 will work properly on the TM36-68?
Has anyone tried the TM40 drain plug?

Doug


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