KMX200-A1 Q-Commuter

[yanw]

My commute is about 10 miles with a legal top speed of 50 mph. I am trying to make the ultimate sleeper/Q-car commuter bike; lots of power/grunt, light weight, high bars for traffic weaving, can tackle any state of road/floods (I live in Gloucester) but looks like a 125cc old dog.

Here's the bike with her fitter younger step-sister last summer:


While rebuilding the clutch over Christmas I heard a frightening "crack" sound come from the KIPS value rack. I took off the head and the RHS KIPS valve was broken. The LHS was missing except fo a small stub sticking out of the head to give the impression that there was one there:


Through the wonders of this forum I discovered that BDK Race Engineering were trying to make replacement KIPS valves as there was a worldwide drought. God bless ya Brock and James. And hats off to James on this forum for sending them his intact KIPS valves to make copies of. They were perhaps the last two remaining KMX200 KIPS valves in the world......

While I have been waiting I have striped, cleaned and rebuilt the carb with a £24 Keyster kit from NRP motorcycle carburettor repair specialist. Service was good and the gent was nice and friendly on the email. I have upjetted the main by two sizes in preparation of the engine work and I have some fresh BR8ES plugs ready to do some chops.

I had a friend who had a small ultrasonic cleaner and the DIY ultrasonics worked quite well however if I was doing it again I would send it/them to these boy(o)s who charge about £15 per stripped carb Ultra Clean Carbs. Doing it yourself was OK but £15 is worth spending to avoid the grief I got for all the noise/mess from the wife.

The before and after carbs:


The next job was some Boysen dual stage reeds. I spoke with James at BDK and he strongly recommended retaining the plastic block in the reed housing as it is needed to smooth the flow between the manifold and the reeds. He also suggested removing material from the reed windows as the Boysen reeds cover the whole block. About half was advised along with smoothing any blobs inside. The picture below shows the change from standard to dual-stage with the pile of fillings being what was removed:


The next stage is to put the tuned head, barrels and KIPS bottle expansion on. They are sat in the parcel office over the weekend as we were out when the courier bought them back from BDK.

More posts to follow!

[kmx200a2]

Hi Yan,

Coming on well, good to see the modding to the STD reed block - something I wondered how to do. I'm sure it you'll notice the difference when both powervalves are in place & other mods too.

Think the kmx200 will make a good town bike, even in standard trim they have a good power to weight ratio, making them rapid through the gears.

I'll keep an eye out for more updates

Dave

[yanw]

Thanks for the encouragement Dave

I have been reading up on an airbox snorkel mod and while I wait for my parcel I took the saw, file and sandpaper to the airbox lid:

[JAMES.L]

strange mod to see on the reed block but only testing will tell if it works, glad i could help ya out by sending bdk my valves, i seen they were struggling to get some so thought id help out

[yanw]

I picked up the parcel from BDK and unwrapped it. It's hard to see from the photos but they have skimmed and levelled the head and done some very nice work on the barrels. The barrel photos didn't come out very well so I haven't bothered putting them up here:


I was going to just leave the head and barrels dirty on the outside but I got a bit excited and dug out the high temp black rattle can. A good tip when masking off the head and barrel is to put coins on masking tape, cut round them and then put the perfect circles in place. I must admit it does look a lot nicer now:


Either I hadn't got the water pump gasket in the set or more likely I lost it in the garage so rather than shelling out I took the advice from the "old boys" on the tzr250.com forum and tried my hand at making my own. £3 on eBay got me two A4 sheets of .5mm gasket paper and with a combination of a ball-peen hammer and a new Stanley knife blade I managed to make a new gasket (second attempt). There are some good guides on the web and youtube and I recommend bolting down the paper to stop it moving. It's quite easy and I drew around the new base gasket ready for "next time".:


The piston has been taken out and a new small end and cir-clips ordered. Everyone on eBay wanted £8 for circlips for a 16mm gudgeon pin but I found a scooter shop selling the right sized ones (for a Lambretta) for £3 delivered. I cleaned the piston up with Carb cleaner solvent as caustic soda can eat away at the metal. The rings were checked in the barrel and were well within tolerance.

I have tried to order a Twin-Air replacement air filter but motocrossworld.com haven't got one in stock and their USA supplier has said "it will be a couple of months". I might have to clean up the old one and re-oil it, it's not in too bad shape. The next job along with the barrel going back on is to re-wad the exhaust, has anyone got experience of this? Is it better to use the sheet or the loose wool?.

Then it's just the wait for some KIPS valves.

[kmx200a2]

The next job along with the barrel going back on is to re-wad the exhaust, has anyone got experience of this? Is it better to use the sheet or the loose wool?.

Then it's just the wait for some KIPS valves.

Hey Yan, depends what silencer you're using. If you're using a DEP or simular then just use some wadding. For example

KAWASAKI KXF450 KXF 450 EXHAUST SILENCER PACKING | eBay

[yanw]

Cheers fella, it's standard but I will give it a go.

I'll have to promote your KMX200 build thread over at bikechatforums.com. It's giving me lots of ideas/leading me astray.

[kmx200a2]

I've never repacked a standard silencer - I had a look at one recently but it was baffling (haha) me how to get it apart.

Kawasaki list a specific part for the baffle packing (Part number 180461090). Its unclear to me whether this just slips over the baffle end or whether the silencer can be properly dismantled and loose wool/packing used.

[yanw]

I took the three screws out last night for a look. What I will do is make a "roll" the correct length to slide in between the inner and outer baffle, not tightly packed but not flapping around. I will post some pics and report on progress when the wadding arrives (Saturday all being well).

[jimbob82]

hi guys , sorry to interupt your thread, was just wondered how your build was going ? did a nut n bolt rebuild on a kmx125 myself a couple a yr ago , but sold it so thinking about doing another one soon

[kmx200a2]

Hi mate - I'd say go for it, I've had 2 kmx200's now - they are great bikes. I've never ridden the 125 but from what I've heard the 200 is a more flexible bike due to stronger mid-range power.

Hopefully you do get started on one so we can see another build thread going on !

[yanw]

Well, I have repacked the silencer and will post pictures on how I did that over the weekend.

I have put the piston, barrel and carb back on the bike but as I am still waiting for the new KIPS valves from BDK the rest of the build has been on hold. The carb has been overflowing since I put it back on the bike so it will have to come back off and be checked. It has had all new internals and the float height checked so I was rather hoping I wouldn't have any grief from it. Such is life.

[yanw]

For the standard exhaust packing I purchased some wadding off eBay. I cut a section 120mm x 130mm and after taking the end-cap off I used the "special Kawasaki tool" to stuff the wadding in.



I am still waiting on the KIPS valves so it will be a few more weeks before I get to see how effective it is. I have taken the time to buy a bottle of caustic soda to decoke the expansion chamber so hopefully it will exhale a bit better.

I have read that the standard exhaust works better with wadding in the silencer as it changes the pressure in the pipe (and hence the back wave to push the fuel/air mix back into the combustion chamber). With a bit of luck I will also get less attention from the police

[yanw]

I got some bad news from motocrossworld.com today. They have been trying to source me a Twin-Air filter but apparently Twin-Air, Kawasaki and everyone else has stopped making them for 200's.

The best he could offer was a Kawasaki NOS KMX125 air filter for £17 + vat.

[kmx200a2]

Bit annoying about the Twin-Air filters not being made any more - had heard they were pretty good.

Good to see the silencer repacked - I like the standard silencer as it is pretty quiet and its sturdy. Only problem was mine was getting so hot the side panel was beginning to melt ! Seemed like it had no packing in it.

i've been using a KX 250 silencer which sounds great but its really loud ! I've found a KDX200 DEP silencer which I'm going to try. Its a bit longer than the KMX200 DEP, so hopefully a bit quieter.

Hope you get your power valves back soon so you can get it fired up !

[yanw]

Well, as you have hopefully seen BDK have got the new KIPS valves made and I received my pair on Monday.

I popped them in and put the rest of the engine together but when I kicked it over there was a squeaking noise. Bugger, there must be a leak somewhere.

What I did was to slowly crank the bike over so there was pressure in the crankcases and then spooned some of the kids bubble mix over the gasket joints:



It was the base gasket on the right hand side. A quick un-torque then re-torque and there was no more bubbles.

The bike still wasn't starting so I dumped the 6 month old fuel in the car and got some new fuel. It started second kick.

After a little bit of fettling it is ready for an MOT (Government annual safety check in the UK) tomorrow morning . I have jetted it rich as I have had the engine tweaked but I should get an idea how it runs tomorrow. Once I am road legal I can go about doing some plug chops and working my way back down the jet sizes.

I will post some more once I have played with the carb a bit more.

[yanw]

It passed first time without any advisorys . The mechanic said the front brake was a bit pants but I knew that. Once I had drained the tea coloured fluid, flushed the lines and put some new stuff in it got much better. I don't thing I will be shelling out for a braided line quite yet.

It is bogging down at about 6.5Krpm so the jetting will need looking at but at least I have my ride back for work.

[kmx200a2]

good to hear about progress on the kmx.

not sure what jetting your using at the moment, but i've found a 117.5 main jet is working well for me at the moment (still running in after rebore + piston)

be good to hear how the engine is performing once the jetting is sorted.

[yanw]

Thanks for the advice about the main you are running Dave, it makes me glad I went up 3 sizes before I put it back on the road, I probably would have melted a piston by now otherwise.

I took it out and did a plug-chop on WOT last night but if anything it was lean on the 120 main jet. I checked the airfilter and there was a gap free-flowing. I cleaned and oiled the old filter I had and it was running a bit better this morning across the whole rev range. I will do another chop tonight or tomorrow and try to post some pictures.

If you want a good guide on carb jetting try here. It's for KDXs but it covers jetting a 2T beautifully.

I also need to take the top engine-to-frame mounts off and make the holes slightly oval. As the head has been skimmed it sits lower in the frame and the mount is lifting it off slightly at the back (I think) and I am getting a very-very slight weep of coolant.

[kmx200a2]

Did you get to the bottom of the leaking head at all ?

I'd be inclined to use a new head gasket if no joy - or if re-using the old one smear instant gasket over it.

On the rear engine mount - unless you had to force the bolt through the mounts & through the cylinder head then its not going to make a difference.
That bolt should slide through the back of the cylinder head nice and easy. If its awkward to push that bolt though then you'll need to modify the mount as you say.