kicker Posted August 5, 2021 Author Share Posted August 5, 2021 Not much progress at the moment, waiting on some transmission bearings and case sealant to arrive but other things are under way. I sourced some of these things Which will let me use the bigger one of these. Stock on the SR is a 28mm carby, dirt 200 is 35mm. The SR has oil injection through a port in the inlet rubber, the new inlet I will use doesn't have this as the 35mm carbs are used on premix only bikes. So I'll drill an unused boss on the carb and feed it in through there. 6 1 Quote Link to comment Share on other sites More sharing options...
Goat Posted August 5, 2021 Share Posted August 5, 2021 Will you need to add a but more oil metering to compensate for bigger carb? 1 Quote Link to comment Share on other sites More sharing options...
kicker Posted August 5, 2021 Author Share Posted August 5, 2021 Yeah, I would assume so. More air = more fuel combined with stock oil flow would make a weaker fuel oil mix. Was thinking I would run it premix to start with and do some measurements on the oil injection pump. It has some adjustment in it so will see if I can get more flow, it may only adjust when it goes full open but we'll have a look anyway. 1 Quote Link to comment Share on other sites More sharing options...
kicker Posted August 6, 2021 Author Share Posted August 6, 2021 Will see how painful the whole process becomes, premix might be easiest long term but not the best for keeping the power valves spooge free Quote Link to comment Share on other sites More sharing options...
kicker Posted August 14, 2021 Author Share Posted August 14, 2021 Some stuff arrived. Step 1 Step 2 Step 3 Step 4: press in the seals Step 5 Step 6: press in the rest of the bearings cos the heat and freeze method didn't work 8 Quote Link to comment Share on other sites More sharing options...
Popular Post kicker Posted August 15, 2021 Author Popular Post Share Posted August 15, 2021 A bit more today. I fitted the freshly rebuilt crank to the right case half. I used the hot slug method. You put the crank in the freezer then heat up a socket with a gas torch, the socket sits snugly in the bearing inner race and heats it up making it expand. When you feel the bearing give a bit of resistance take the socket out then get the crank out of the freezer and push it straight into the bearing using feeler gauges to centre it in the case. The main reason for doing it this way is because using a torch or heat gun might cook the crank seals which have to be installed first. Now time for gearbox reassembly and pressed in a couple seals to finish off 15 Quote Link to comment Share on other sites More sharing options...
Popular Post kicker Posted August 18, 2021 Author Popular Post Share Posted August 18, 2021 Ooh yeah, crankcase halves went together easy. Used the hot slug again, had even made a crank puller in case it got stuck part way on but didn't need it. Gear shifter and kick start mechanisms in along with the oil pump drive gear, will torque up the primary when the clutch goes on. Next up is cleaning the sidecover and replacing some more seals. 12 Quote Link to comment Share on other sites More sharing options...
kicker Posted August 20, 2021 Author Share Posted August 20, 2021 Crankcase all back together. I found it is missing a washer on the clutch release mechanism, I can't see how it would negatively impact it other than reducing its throw and it has been running for who knows how long without it but I'll order a new one as its a 5 min job to install. I'm still waiting on an output shaft collar to arrive and need to order a new piston but in the meantime I can move on to cleaning up the cylinder and the powervalves. 4 Quote Link to comment Share on other sites More sharing options...
kicker Posted August 26, 2021 Author Share Posted August 26, 2021 I have cleaned up the cylinder and power valves, there was a lot of spooge but a soak in some petrol made it easy. Valves back in now and operating smoothly. Here are the valves in their closed state which is below 4000ish rpm, you can see the centre valve at the top of the port and one of the side valves to the left. Open state, you can now see the extra exhaust ports that the side valve uncovers. From the top you can see the main exhaust port and the extra two on either side the power valves control. Nothing left to do engine wise at the moment so I gave the frame a clean so that it's ready. 8 Quote Link to comment Share on other sites More sharing options...
Popular Post kicker Posted August 31, 2021 Author Popular Post Share Posted August 31, 2021 The engine rebuild is pretty much all done, after getting it all back together I found the kickstart shaft and shifter springs had unseated during assembly so had to drop the oil and coolant and open up the sidecover again. All good now. Sounds a lot crisper too, some of that will be due to the gutted expansion chamber. Before and after I haven't been able to ride it yet but hopefully I can soon, in the meantime I still need to install the light for my new plate bracket and can try out the new silencer. Also, typical for bikes like this it has a chewed up kickstart shaft thread I have to deal with, now that its all done I might just send it with some stud lock and hunt down a nicer shaft for the future. An old flatmate of mine had a KX125 with the same problem, his didn't even have a nut, and if you forgot to take the lever off after starting it'd fall off somewhere while riding and you'd spend ages trying to find it. 9 3 Quote Link to comment Share on other sites More sharing options...
Popular Post kicker Posted September 9, 2021 Author Popular Post Share Posted September 9, 2021 I made a new bit of exhaust for the Toomey silencer so tried that out. Not any louder but sounds a little better. Today was engine break in day, had done a couple heat cycles on the stand so time to load it up on the road. It's got a lot more zing now, pulls hard when the pipe comes on, lots of fun. 11 Quote Link to comment Share on other sites More sharing options...
Truenotch Posted September 15, 2021 Share Posted September 15, 2021 This things coming together well! ... You should consider joining our 250 gang for the East Cape mission in November. We're going to start from Palmy . 5 1 Quote Link to comment Share on other sites More sharing options...
Goat Posted September 15, 2021 Share Posted September 15, 2021 This thing goes like a cut blanket on a cat. So much grin. Can only imagine what its like with the big boy carb. 2 Quote Link to comment Share on other sites More sharing options...
kicker Posted September 16, 2021 Author Share Posted September 16, 2021 For only 200cc it can be a bit of a handful. Power comes on very quickly once the revs are up, wants to lift the front all the time so need to get up over the bars but it still has decent low down power so can be ridden civilly. I need to clean up the pilot jet circuit though, feels a bit 4 stroky just off idle. Ideally I'd bung on the replacement carb and tune that but I am still sussing the oiling system. CBF running premix due to hassle and 40:1 at low road rpms will poo everything up, the injection pump runs about 90:1 at idle. I remembered that there is a 250cc version that runs a 33mm carb and oil injection so I picked up the pump from one of them. I suspect the pumps might be identical and are just geared differently, if that is the case I should have the option of swapping gears or boring the pump and making a new piston for it. 9 Quote Link to comment Share on other sites More sharing options...
johnnyfive Posted September 16, 2021 Share Posted September 16, 2021 This makes me yearn for my old RMX very badly. I regret selling it quite a bit, even though in reality it had a less than ideal life with me. Really enjoying your line of attack with this though 3 Quote Link to comment Share on other sites More sharing options...
peteretep Posted September 16, 2021 Share Posted September 16, 2021 yeah not going to lie, I'm also looking at getting a 2 stroke dirt bike onto the road, KDX is a pretty sweet option and looks reasonably streetable compared to most dirt bikes 6 Quote Link to comment Share on other sites More sharing options...
kicker Posted September 17, 2021 Author Share Posted September 17, 2021 Can recommend, it's the most fun I've had on a bike in a long time 3 Quote Link to comment Share on other sites More sharing options...
peteretep Posted September 17, 2021 Share Posted September 17, 2021 Any particular model you would recommend? I see some have headlights and others don’t, was that just an option when you bought it, but otherwise the same? Quote Link to comment Share on other sites More sharing options...
kicker Posted September 17, 2021 Author Share Posted September 17, 2021 The SR version was the only model designed to be used on road, comes with an extra charging coil and all the lights, speedo etc, regular KDX will just be a headlight and taillight and premix. You can put most of the gear on a non-SR easily enough, the hard part I guess would be compliance and what kind of checks there are that would stop an off road vehicle from being vinned. Early 90's RMX250 is another that had a street legal version, they come in a tasty yellow colour. This one has been listed for a while due to price, it's an F1 version which from what I have seen is just an SR with right way up forks that was for the Oz market.https://www.trademe.co.nz/a/motors/motorbikes/motorbikes/dirt-bikes/kawasaki/listing/3174312600?bof=5vxszvqb There isn't many of these bikes in NZ but they do pop up. Lots on Yahoo Auctions 1 Quote Link to comment Share on other sites More sharing options...
peteretep Posted September 17, 2021 Share Posted September 17, 2021 How do you tell an SR version of the seller doesn’t know? Quote Link to comment Share on other sites More sharing options...
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