My KR250 Project

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250 drummie
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Post by 250 drummie »

Mine did the same thing, the drain plugs had corroded away on mine at the tip and wouldnt seal up. I have two sets of carbs and only one good plug and one still leaks a bit :roll:
Bogan
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Post by Bogan »

You can still get them new I'm pretty sure:

http://www.ronayers.com/Search/N/687/Pa ... /Source/KA

Will pull them apart one day soon and see if that's the problem and order a couple :).
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Post by Bogan »

Rightyo, so there was a long break while I put my dirt bike back together but a mate dropped over today and we got the old drain plugs out of the carby bowls and put the new ones in. One of them still leaks but guess what we made it do anyway...

http://www.youtube.com/watch?v=aENRmGMoXMw

:) :) :) :) :) :)

Now yes, it runs, but it sounds like a tractor and as you can see from my furious wrist action it won't rev. The tacho doesn't register anything above about 1000rpm. And when I go clicking the first related item on Youtube I find this:

http://www.youtube.com/watch?v=hXlrbYV-2dY

The one above by the looks of it was probably posted by someone on here, and it sounds more like my RGV and less like a tractor :).

I'm assuming that a carby rebuild could be on the cards, or maybe pull the chambers off and clean them out? I'm not sure how long since its been run, anyone got anything to offer on whether this sounds normal for an old smoker who has had a long rest and what to do next to get it running something like normally?

Cheers,


Tony
Sheik Yerbouti
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Post by Sheik Yerbouti »

lots more smoke coming from the front cylinder than the back. Could be a clue??? dunno
Sounds pretty rich and too much oil to me. If its been sitting a long time, you tend to get the bottom of the crankcase full of old schitty oil thats been left behind from fuel which evaporated long ago.
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ScottaKR
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Post by ScottaKR »

Sounds like it's only running on 1 cylinder to me. Check youve got spark at both plugs, then look at your carbs (clean and syncronize them).
KR250 Tandem Twin (Naked) :mrgreen:
KR1 Red/White
KR1S Track Bike (has been put on hold for now)
ZXR750 H1 (Winter project)
250 drummie
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Post by 250 drummie »

Yep I agree one cylinder and it looks like the rear is dead. Strip the carbs and as Scott said check for a spark. May be a dud CDI or coil. Still nearly there =D>
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Post by StrokerBoy »

Bogan wrote:http://www.youtube.com/watch?v=hXlrbYV-2dY

The one above by the looks of it was probably posted by someone on here, and it sounds more like my RGV and less like a tractor :).
Yeah, that's mine. And here's my OTHER ONE.

Yours is definitely only running on the front pot. Didn't sound like the rear one was even trying. Sparks and fuel. Swap some stuff over and see if you can pin it down.

But well done on getting some life out of it, you'll soon be sorted. :D
Kawasaki KR250 Tandem Twin (x4) & KS-II 80,
Yamaha RD350LC,
Suzuki GSX-R750RK & RB50 Gag.
Bogan
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Post by Bogan »

First thing I'm going to do is pull the carbies down, there's been talk on other sites about Keyster Motorcycle Carb Kits does anyone know if Keyster or anyone else do a carby kit for the KR250 carbies?

I am pretty sure it's the back one that's leaking out of the fuel bowl, and when we pulled the intake rubbers off from the airbox there was lots of droplets of fuel as opposed to atomised fuel splashing around in the carb. There's spark to the lead but I haven't pulled the plug to see if that's still any good, a pair of spark plugs is cheap so I might give that a go too.

Thanks all.

And strokerboy they sound like fun, do you have any pics of it moving or just sitting still revving?

Cheers all,


Tony
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Post by StrokerBoy »

Bogan wrote:strokerboy they sound like fun, do you have any pics of it moving or just sitting still revving?
No, need to get some though. Will rope the missus in to help with some more video when the weather improves here.
Kawasaki KR250 Tandem Twin (x4) & KS-II 80,
Yamaha RD350LC,
Suzuki GSX-R750RK & RB50 Gag.
Bogan
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Post by Bogan »

Looking at the parts book can be really handy, thanks for scanning it Scott :). I can tell everyone that the following parts are still available from Kawasaki Australia:

Gear lever rubber.
Exhaust gaskets between barrel and chamber.
Rubber mount that the front of the fuel tank sits on.
I'll be buying a couple of plugs too.

There's spark at both plug leads, so if I get new plugs there should be spark in both barrels. I'm pretty sure it's the back carby, weird thing is when we replaced the drain plugs (also still available new) and filled the bowls with WD40 they didn't leak out the bottom but as soon as I put it back on the carby and turn the fuel on there is fuel leaking out of the drain hole. Would it be coming from somewhere else?

I'll give the carbies a going over I would think that they're to blame, particularly the back one.

Any leads on Keyster or other carby overhaul kits?
Last edited by Bogan on Tue Feb 08, 2011 10:49 pm, edited 1 time in total.
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ScottaKR
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Post by ScottaKR »

Hi Tony, I think it was Tim (strokerboy) that scanned the parts book.
If the fuel is only coming out when the carb is connected then your floats are either incorrectly set, or the float needle valve is worn/dirty.
KR250 Tandem Twin (Naked) :mrgreen:
KR1 Red/White
KR1S Track Bike (has been put on hold for now)
ZXR750 H1 (Winter project)
Bogan
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Post by Bogan »

I should get a needle and seat in a carby kit if I can find one yeah?
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Post by Bogan »

I had a look over the internet and it appears as though the carbies are Mikuni VM28SS, unless they're Keihin, which I found on another site.

If it's the Mikuni would the KR carbs (2 stroke) be different to the VM28SS on the Z1R (Z1000D) which is a 4 stroke?

I found this page which states Keihin and this page which says Mikuni.

Also these pages state Mikuni:

http://www.kr250.org/manual/KR_manual_chapter_2.pdf (workshop manual scan)
http://motorbike-search-engine.co.uk/cl ... cation.php

The best bet would be to look at the carbies I would guess, I'll probably pull them off this weekend and try to rebuild them.
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ScottaKR
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Post by ScottaKR »

They're Mikuni's mate.
Pull them off, clean them out, make sure the needles and jets etc ALL match up, set the float hieght correctly, and then make sure they're syncronised when you put them back on. That and a pair of plugs, and I'd expect it to be running quite nicely.
KR250 Tandem Twin (Naked) :mrgreen:
KR1 Red/White
KR1S Track Bike (has been put on hold for now)
ZXR750 H1 (Winter project)
Bogan
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Post by Bogan »

Rightyo there's been some progress today. The easy simple bit was putting some brake fluid in the front brakes and bleeding up some sort of feel to the lever. It's sitting in the shed with a cable tie on it now we'll see how it is tomorrow.

I got the carbies off and cleaned them up as much as I could, got the floats off, needle and seats out, main and pilot jets out, choke plungers out, blew everything out with air and carby cleaner, and reassembled them and put them back on.

Replaced the spark plugs, which it looks like the previous owner did as well, the ones that came out looked pretty new so I have a good pair of spares :kuda:.

Pulled the exhausts off as well, and bought some caustic soda to flush them out with. Interestingly when I was moving the bottom one (the one that runs, the front cylinder) into the garage to start the cleanup this happened:

Image

There was quite a bit of oil in there...

Image

The baffle I don't think will come out...

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I'm gonna fill the chambers with caustic soda and see how much weight they can lose, I had to undo the rear subframe to get the rear exhaust off, this pic is looking forward towards the engine with the battery box and right hand coil removed, it's fun to get out:

Image

Oh yeah and if anyone tells you that the only difference between one battery and another is that the vent pipe is on the other side make sure you don't just settle for the wrong one, I had to cut the vent outlet off:

Image

This big hole is for the vent pipe bit to stick out and there's no big hole on the other side :).

Image

Once the exhausts are clean and back on I'll kick it in the guts again and report back...
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