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Kt250 A1Restoration Project


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Hi All

Newbee here looking some advice for a KT250 resto project I just started.

Going to try my hand at riding trials next spring and preping a bike to learn on.

I would like to do a complete resto, as best as possible within reason, since I do want to ride the bike.

It looks pretty complete but have already seen parts that dont match the Parts Manual I bought.

Are there any KT250 folks here?

Current parts I know I need to source are

- Seat

- Carb,air box boot

- Sprockets and Chain

Would ike to add a compression release, since head is drilled for it already, anyone do this?

Direct email, if desired is 82indypc@gmail.com



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Hi Tim

I'm one of the KT folk. I have one of my own, and have helped a few people with theirs. I've ridden mine quite a bit over the past 15 years and experimented with lots of things to see what effect they had.

The carb is a popular item for use on other twinshock trials bikes so it's not unusual that it is missing

The airbox boot shrinks and goes hard with time and new replicas can be bought from Fred an Deb's KT parts in New Zealand. They also have lots of other hard-to-get replica parts for KTs


I don't know why the seats disappear. I have given a couple away to people whose bikes were missing them but have no more left.

Front sprockets for 520 chain are available from http://www.tytrials.co.uk/trailandtrialsuk/cat_28895-3-Kawasaki-KT250-Parts.html

Rear sprockets are not as readily available, due to being dished. A flat sprocket from Talon with spacer and recessed head fasteners will work. Some people have made sprocket adaptors to allow the use of late model KX sprockets but the last time I saw these being advertised was years ago.

What parts look different to the parts book?

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Fantastic to see a fellow KTer!!

Thanks for the info.

Not sure what the seat history on this bike is other than person wanted a seat more for trail riding so adapted the original seat bracket to a cut down seat from another bike. There is guy on ebay that sells KT seat covers, I asked him how many he sells, to get a feel how many KTs may be out there. He says he sells about 10/yr about 80% in North America else over seas.

Parts that I have seen thus far that are different than the parts diagrams.

P/N 92072-036 Band, Fuel Tank

Parts diagram show this as a double ended rubber strap, like it would connect to two tabs on the frame.

The one I have is a rubber square loop with at pull tab on the top, it hook to a single tab on the main frame down tube on the frame. I will take a pic of this part.

PN 11010-092 Air Cleaner Assy

My air box has 3 bolts holding the outer cover on, with one bolt that is cut short and could be stripped.

Parts image shows two bolts.

Here is the link to my project pic album, all updates go here


Here are the air box bolts bolts






I also see from the Part Diagram for the frame, it shows the rear shock mount area has the shock mount stud, bolt hole for the seat AND another hole further back, but that other hole and metal gusset is not on my frame.

I thought perhaps I do not have a KT250 frame, perhaps some other frame.

My Frame number is KT2-03028, does that look like a KT250 Frame?

I know the 1976 KT250 has some differences, my parts manual has those differences show and I have check those diagrams for each diff I see.

I do have what looks like the original carb, yes the boot has harden and would like to replace. Current one is pretty messed up.


Thanks for the lead on a new one, I will replace it.

I see some reproduction KT parts also available from


The dished rear sprocket is the same issue on the Ossa MAR/Explorer. Same solution, spacer and flat sprocket.

I see there is a 520 chain and sprocket conversion, is that a common conversion. I would like to put new chain and sprockets on this bike as the rear sprocket is shot.



What do you run as an air clean element?

I dont see a UNI filter available. Is what I have stock, does not seem so to me and does not look like it would be sealed well.





(Update, I see the UniFlow filter available from UK trials source, odd its not available in the USA)

Finally, seems this site use to be a KT fan site but not sure anyone goes there anymore, cannot see how to post a message there. Do you know if its still active. I downloaded several manuals from there but in the end I bought my own Parts Manual from ebay, the downloaded PDF images were not very clear, so I bought and scanned my own. The parts fiche is my bible on any of my restoration project, although sometimes have errors.


(Update, see the Fred site is off of this website)

Thanks again for any advise or help. Its extremely helpful to come up to speed quickly on a new make/model for me. I am mostly an Hodaka/Ossa guy, although I do have several KDX bikes, Red model.



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The Uniflow air filter elements that are sold in the UK are made in Sydney, Australia. They used a KT airbox of mine to design that filter. Fred and Deb KT parts also sell those filter elements. I use them and have no problems. I'll have a look at your photos now.

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Apart from the one damaged lid stud on your airbox,it looks like standard KT

Your frame is standard KT behind the shockie mount. The standard seat brackets attach where the brackets on your seat attach

I'll have a look in my parts book to see what you are seeing

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Cool Pics!!

Starting the youngster early I see.

Thanks for the pointer to Fed. Working on a mega order that may require a second mortgage on my house to cover shipping cost to USA, LOL.

But I do want to put back on original fenders, will use my beaters while learning and dumping a lot, but eventually would like to put her back mostly stock. Will get air filter element, carb boot, fender brackets, seat pan, fork seals, dust covers etc etc.

Usually when go through a bike I replace as much rubber parts as possible, all bearings, switch steering to tapered bearing and do swing arm bushings. I see on the KT the swing are pushing are rubber collared, those can be a real pain to get out. They seem really tight but hard to know unless really riding. Have you and any issues with them wearing out? On my Ossa and Hodaka there are grease fittings in the swing arm to keep them lubed up good. I also replace them due to powder coating the frame and the rubber does not always hold up to the 450 degree oven. Other bikes I have worked on dont have the rubber in the swing arm, except small bikes, usually nylon, delrin, or metal bushings. Not sure I want to try and replace these unless the come out of the oven cooked.

Got most of the rest of the bike torn down today, getting ready for frame sandblast then to powder coater in next few days. Thought I was going to have to pull the head to get the pipe off, then saw with motor bolts all removed it JUST comes off. Will have to remember to put that in the frame before I put the motor back in. On my Ossa Explorer the head and jug have to come off to put the motor back in the frame, they all seem to be different.

Other than the rear axle everything came apart smoothly. I suspect I should look at some other rear shocks if I am really going to seriously ride this bike, original I suspect are beat and may be leaking. Can they be rebuilt?

Think I will have to make a seat from Freds fiberglass pan, a cover off of ebay and get a seat maker to shape the foam thats needed. That is unless I can find one for under $200.

I purchase a bunch of parts off of ebay today, carb gasket and insolator, still need the piece that connects to the carb, one on the bike has tons of black silicon on it so expect it leaks. Started trying to find tail light parts, got the fender rubber gasket, now to find the innards and lens.

Inside of the gas tank has some rust, so will clean and treat that. Looks like I have a 76 tank as a spare, different paint job, has some small dents so may use that for riding, going to keep the original as is for now, along with side covers, only original paint once as they say.

Rest of the bike looks pretty complete to the parts catalog, will refresh any damaged hardware.

High Low beam switch is broken off, seems to be common from pics I have seen of other bikes. Kill switch may be bad also as prior owner said he had to disconnect it to get spark, may be able to fix that though.

Are there any common upgrades folks do to improve the bike. I see several sites selling different adjustable levers.

Think will add the compression release like I have on my Ossa, useful for starting sometimes and breaking.

Glad there is not many chrome parts on this bike, thats always a problem, cost prohibitive these days to get things rechromed, generally just have to rough up and powercoat some color.

Thanks again for all the help, advise and contacts. Going to be a fun project and cool bike when done.

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The standard pipe will come off without having to undo the motor mounting bolts or the cylinder head - however there is a knack

The carb to cylinder connector is a common failure

I haven't ever touched the rubber swingarm bushes, but if I wanted to take them out I would just burn the rubber and cut the outer sleeve to get them out. There's a bloke from the US called Michael Moore who wrote a great story about his KT that he was fixing up about 10 years ago. Michael didn't like the rubber swingarm bush idea and made a metal to metal setup and explained how and why he did it the way he did. He also experimented with different exhausts and explained how he went about it. From what you say it sounds like you like to have things completely standard so probably wouldn't suit you. In case you are interested, you may find Michael's writings about his KT on Trials Central forums.

You won't need a decomp to start it - they are a pussycat to kickstart

There's a bloke in Australia was making replica KT taillights a while back. They look like TY taillights but are different in detail. He bought my original light to copy from. haven't heard from him for a while

The three position clutch levers are rubbish. A good quality clutch cable is a benefit. Some people use the clutch cover off one of the KX bikes to get a better clutch pull.

Getting the fork action sorted and the rear ride height right is important for getting the steering to work well.

High rise bars (like they had at the time) are a good idea with the standard footpeg position

Good modern shocks have a much better action than the original KT shocks, but if you want to keep it original looking, there is no such thing as a shock that can't be rebuilt

Original KT mudguards are moulded plastic, not sure what you mean by "beaters, learning and dumping a lot"

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Ha, so there is a secret method to get the bike off, I tried for a while to find a special angle twist, turn etc, guess experience tells all. One of the reasons I take a zillion pics on tear down is so I have a sequence I can reverse when put it all back together, often many months later. At my age the memory is not so good any more. Doing several bikes at the same time does not help LOL.

Trying to find one of those carb connectors, asked Fed but have not heard back yet. No stock on any of the parts websites here.

yeah most of my other bikes do not have rubber inserts in swing arm, can see how some would not like it, must be some side give if riding hard, but for this type of bike may be fine. I will see what happens after it goes through the oven. Never put those type in so not sure if a press is needed or not.

A reproduction tail light would be fine with me, not going for museum level resto, just as original looking as possible. If you happen to hear from him again I would appreciate a lead, I will continue to search as well. Looking through all the past KT posting on this site, since its the new home for most all KT talk.

Good to know on the 3 Pos clutch lever, thanks, will replace the cable if find its not smooth when its all back together.

I have what I think is the original bars so will keep with that. See some use bars with cross bar, like MX bikes, but think I would prefer the open area to avoid collision with face etc.

Pegs on this bike seem odd, no real grip points for the boots. See there are other weld on pegs available. Really dont want to do that. If they are really slippery I may just MIG weld on some bigger nubs. Some say the are too close to the frame and offer extension. Since I am a newbee to the sport I would not realize a good vs bad setup until someone told me directly.

What I mean by "beaters, learning and dumping a lot" was, I do have front and rear fenders already, the rear is cracked and the front have been drilled several times. I will order from Fred the original style reproductions for the proper look but may use what I have already for a while. Like I said I am new to the sport, have ridden bikes since 70s, but never trials. Will be attending a beginners school for a day this spring, put on by our local twin shock air cooled trials group. http://newyorkaircooledtrials.com/%C2'> I have been going to their events for several years and they have all classes of air cooled bike as well as all ages of riders.

Thanks again for all the info, very helpful without doubt.

Couple new items

Do most run the stock gearing, front and rear sprockets?

I suspect I will do the flat rear sprocket with adapter to get away from the dish sprocket. This will deviate from stock but since I intend to ride this a bunch ability to change out rear flat sprockets is a must.

What about chain size? Stock or the 520 conversion? Any issue with clearance once going to 520?

Read last eve that long thread on electrical problems on one guys bike, turned out to be leaking spark plug wire onto exhaust pipe, crazy.

I may add a voltage regulator, we do the same on the old Hodaka bikes, or maybe just run the 12V bulbs like you said you do.

Lastly are there any other Kawi bikes that cross over basic parts, such as carb/intake, hardware etc. I have seen one ebay auction that ref all these bikes but think thats just on wheels and spokes. Do you know of a cross over chart for all common parts on kawi models by part number. I have done some searching but could not find anything published. Wonder if there was a dealer master parts list that showed all P/N vs models.

Cross Over

1977 KD125 KT125 KD175 KT250

Backt to tear down. Hopefully off to sand baster today or tomorrow.

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gearing needs to be lower/slower than standard for competition. I use standard rear sprocket whatever that is - probably something like 52T - and 12T or 13T front with 428 chain. I will look in my log tonight for the sprocket sizes. Standard gearing is something like 15T front from memory and is great for highway cruising

You should be able to run 520 chain without clearance issues, and it is probably a good idea to go for 520 because 12T or 13 T fronts for 428 chain are hard to find

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