Combining 85 kxt with 88kxf

[Tecate250]

I just bought my old tecate 3 back for 450 cnd.
From the time i sold it it lost the perfectly good fame to the dump the axel, stock carb and various parts. I also have my almost complete tecate 4 motor with stator but bad and i mean bad magneto. The carb that is on it is not the stock carb and wanted to know if the flat side carb off the t4 will fit and if not which jets do I use? I also remember someone talking about modify a honda 125 m magneto works fine. But my stock t3 stator with mag looks like the t4 one. Can a t4 stator work with the t3 magneto?And which stators/magfrom kawasaki will work on a tecate 3? I have a stator assembly but there is no lighting coil and the magnets are held in by bolts. And 1 bolt shock loose. Must be from the power lol.Also the stock shock is trashed and not fixable. But I have a freshly rebuilt t4 shock to use on it. But the t4 shock is short by 1-2 inches. Can I use the adjustable uni link off a 86-87 t3 to compensate for the shock height? An speaking of uni link. When I bought the bike the first time someone threw away the uni trak and welded in a mount on the piece of the frame above the uni trak. Is this piece of frame designed to hit the uni trak at any time? And not having this piece of the frame is it crutial? Which is the better motor? the t4 or the t3? and how much hp do each put out?

Wow what a mouth full.

[Jeb]

The Tecate4 motor is counterbalanced and a six speed. It's got a different exhaust port than the 85 KXT motor. The exhaust is centered on the 87-88KXF and 86/87 KXTs (which didn't have a counterbalancer and were 5-speed). The 84-85 KXT has a slanted exhaust port and is not power-valved.

You should be able to swap the stator and flywheel between the two, but you might want to swap the CDI and coil too.

Also sounds like someone welded a shock mount onto your frame for a no-link swingarm setup. I'm not sure if that will hit or not. You'd have to put it all togther and see how it worked. If it all works you can use the adjustable linkage from the 86.

[Tecate250]

Well I grinded off the rigged up mount. I was just wondering if the uni trak wasd suspose to hit at all. And the shock is 2 inches too short. So instead of loosing 2 inches of travel can the 86 adjustable linkage compensate for the lose of shock.

[Jeb]

I think it's safe to say that with a stock shock the UNI-TRAK linkage is not supposed to bottom out on the frame or interfere with it in any way. They used to run shortened shocks for flat-track. That's a shock with less travel. I'm not familiar with the spec's on the Tecate-4's uni-trak but I do know it's quite an updated design compared to the Tecate 3 wheelers. I guess again it's possible the linkage could hit up under the seat under full compression if the Tecate-4 shock is shorter but has the same or a just bit more travel. That scenario could cause the rocker arm to "over-rotate" past its intended stopping point in the travel.

I'm not sure if you could adjust the 86 link enough to make up a 2" difference on the 85 model. If the shock is a bit shorter and travels further that adjustable strut would get some or maybe all of your seat height back but wouldn't necessarily help to keep from bottoming out on the frame.

Oh and one other thing. If someone added a bar across the frame anywhere near the uni-trak linkage pivot in the frame to add a fixed shock mount, I bet it has to be completely removed or the uni-trak will hit it, stock shock or not. You said someone welded a bar across it above the pivot area, i'd say it's got to completely be removed, or at least enough to give the linkage the room it needs to operate.

Can you post a picture of the frame?

Let me know what you find out!

[Tecate250]

Not yet. I have to get my film developed.
I already removed the bar and now my uni trak can spin all the way around.
The 86 and 87 tecate 3 have the adjustable linkage. I was hopping it would compensate for the shorter shock. Id like to get a +2 aluminum swinger.
And I cant find a damb thing for these bikes anymore.
Id like to make it mint again. Its the ugly duckling, like me.

[Tecate250]

Oh I almost forgot.
I read an article about putting a powervalve top end on a tri z.
Could the same be done to a 85 tecate?

[Jeb]

The KXs (83/84) that are compatible with the 85 KXT weren't powervalved. The 85 KX-250 motor is bit more advanced and somewhat different than the 85 Tecate motor. As far as Yamaha's go the YZs were really close to the Tri-Z motor so that's why the Tri-Z can be done.

To add a power-valve cylinder to the 85 KXT motor would be virtually impossible in my opinion. You'd have to make an 85 & up KX or 86 & up KXT power-valve cylinder work on the 85 engine cases and then come up with a way to mod the lower end to actuate the power valve. If you could get this done, then you'd still have to modify the 85 frame to clear the center-port exhaust of the Kawasaki power-valved cylinders.

There's no logic in all that engine modification because the easiest thing to do would be to swap for an 85 or up KX motor or 86/87 KXT motor and mod the frame to clear the exhaust port. Then after that, you will probably run into exhaust pipe problems. I've thought about this before and If I went that far I'd try to use a KXF-250 Tecate4 motor for the six speed tranny and counterbalancer. Since you've got to rebuild the front of the engine cradle anyway why not build for the advancements that motor would offer over a KX or KXT motor?

So in closing, to powervalve an 85 Tecate your looking at extensive motor work and extensive frame & exhaust work if your going to modify the 85 engine. If your going to swap engines, which would be the easiest route to take, your looking at extensive frame and exhaust work.

[Tecate250]

Cool.
The thought of using the Tecate 4 motor has ran into a few problems with its a big motor. I have not measured it up but I think a large part of the front bar will have to be modified to allow the stupid counterballancer.
Are all the kx motors identical in size? I also want to use the stock t4 carb. Flat side Kehin. But dont know where to start on jetting. The 84s were known for a clutch dragging problem? is this why the 85 has a 1 mm longer clutch rod and some other parts that are not interchangeable? What does this allow? Also how much bigger is a kx 500?
Ive thought of using an air cooled 500 to gain in speed and elimate the rad all together. But what kinds of mods must be done to make a 500 work? Ive seen a few atc 500 r mods but never no kxt 500s. I need a new stator kit from Ricky Stator and that is 200. Plus piston ect. So I was thinking of ditching the stock motor and making something just nuts is the word. Im tired of honda guys and banshee guys.
I have everything all primed up including my soon to be white tank.
Just tyrying to gather parts.
They include

Green vented # plate
86/87 adjustable uni trank rod
aluminum swingarm or +2
gas tank mounts
aftermarket pipe
silencer
85 uni trak
85 aftermarket clutch basket
big bore kit

[cliff2302]

if you buy the coil packs for the stator they are only $40. Just unbolt your old packs, cut 4 wires, solder the new ones and bolt them back on. Saves alot of money.

[Jeb]

if you buy the coil packs for the stator they are only $40. Just unbolt your old packs, cut 4 wires, solder the new ones and bolt them back on. Saves alot of money.

Good Advice.


Take a look at these two frame pictures.

All KX500 liquid and air cooled motors need a frame with the front of the engine cradle like the 86 KXT. I know if you look at the air cooled 83 KX500 frame on www.buykawasaki.com it shows a "wishbone" type frame too. So you will probably have to rebuild the front of the 85 frame to look like the 86 for any KX500 motor. I believe the liquid cooled kx500 motors 85 & up will practically bolt right into the 86 KXT frame and probably into the 84/85 frames too but the exhaust port will interfere with the frame on the 84/85 while it clears it on the 86. I think on the 86 model you have to modify the frame a little in the areas above the head to clear the spark plug, but the motor mounts all line up. I know there are guys on this board that have done this very thing. A motor you might look into using for an 84/85 frame is the 81/82 KX420. It's an aircooled motor and the frame is similar in the front to the 85 KXT.

The only KX250 motors you can use without a frame mod is the 83/84. I don't know if the pre-83 air coolers will work or not. All 85 & Up KX250 motors will require you to build the the front of the 85 frame to look like the 86.

[tecatecrazy]

in my opinion, it is pointless to swap out the 84\85 kxt motors for anything else unless you want to make a drag bike. the motors in these bikes already just about out perform the stock suspension set up. with ebay and about $5-700 you will have a bike that is almost out of control. trying to add a big bore or modify the frame to stuff in a 500 and you will need at least a +4 swinger which will make the bike good for the dunes but thats about it. I know its all about power but, just throw on a KX jug and a bigger carb and you wont have any problem with those banshee and hondas smokin ya anymore.

Joe

[Tecate250]

What is the difference between the kx motors and the tecates?
I live in a very rural area and with the tecate parts dieing off at an astoshoning rate Im kinda in a hurry to make here mint.
What aftermarket parts are still around?

[Jeb]

Well, the 83/84 KX250 mill has more aggressive cylinder porting. Bigger carb, different (but better) ignition. I believe it also ran a thinner head gasket for more compression. Not sure about transmission ratios. This is as compared to the 84/85 KXT. Outward appearance, the motors look identicle and will interchange without modification. If you just took a motor out of a KX and dropped into the three-wheeler you couldn't run your lights. But you could add a ligthing coil.

I recommend a +2 swingarm, even for a stock Tecate mill.

As far as aftermarket, I don't know for sure what's available anymore.

[Tecate250]

The transmission gearing is different from atc's to dirt bikes arent they?
If they are would I use stock gearing or would I have to compensate for it?
Why would Kawasaki do that to a "racer". I mean Have better parts in another bike? I for the longest time thought all the " 250" pingers were just the cr,kx,and yz motors in "modified" frames. Is there any info on a 88 kxt 250? I mean there is the 87 r. But kawasaki made the kxt in 87. I wonder what that machine would have been like?

Enough dreaming.
Does the stock 84/85 exhaust system still line up on the 83/84 kx's?
And the shock? Will that fit on the kxt or would it be too long?
The igition system you say is different but better.
How so?

Would a newer kx motor fit in?
Cause I see alot of 250's going pretty cheap. Like 1500 cnd for a 2000.
My buddy has my old T4 is getting ancy to drive it, and I want to own him.
And if the jug is that much better or the motor for that much. And unknown to the naked eye.
Where could I get a swingarm for it?

[Jeb]

The transmission gearing is different from atc's to dirt bikes arent they?

Yes, If I remember right they are a little bit different as far as Tecates are concerned.

If they are would I use stock gearing or would I have to compensate for it?

That's entirely up to you and what riding you do. If you just want to go fast in a straight line, probably no need to re-gear. For trail riding, you might want to re-gear even the stock Tecate motor for more low end.

Why would Kawasaki do that to a "racer". I mean Have better parts in another bike?

Only Kawasaki knows for sure. The Tecate was aimed at a more recreational market and competition as a secondary market. Where as the KX is a closed-course racer aimed at competition first and recreation second.

I for the longest time thought all the " 250" pingers were just the cr,kx,and yz motors in "modified" frames .

Well, no offense, but you've been mistaken for a long time. The "pingers" are based on MX motors but are not identicle to their MX counterparts. The 86 ATC250R motor is very different from the 86 CR250. No powervalve, has a counterbalancer, "forward" kick starter. Visually to the trained eye, they look different.

The 85 Tri-Z is pretty similar to the 84 YZ. Again, the Tri-Z's arent powervalved and the YZ's are. The Tri-Z is a "forward kicker". Visually, the trained eye could spot the powervalve on the YZ.

Both designs of Tecate are very similar to the KX mills they correspond with. With 86/87 motor being almost identicle to the 85/86 KX motor. But both those engines are different from the 87/88 Tecate4. Visually, I would say you'd be hard-pressed to tell the difference between an 83/84 KX250 motor and an 84/85 Tecate motor. Same for 86/87 Tecate motor compared to 85/86 KX250 motor. But on the other hand it would be easy to see the difference between an 85/86 KX250 motor and an 84/85 Tecate motor.

Is there any info on a 88 kxt 250? I mean there is the 87 r. But kawasaki made the kxt in 87. I wonder what that machine would have been like? .

Your guess is as good as anybodies. I think if Kawasaki had tried to get the Tecate through in 88 or sold it elsewhere as an 88 it would have had minor changes from 87, probably only different decals.

Enough dreaming.
Does the stock 84/85 exhaust system still line up on the 83/84 kx's?.

Yes

And the shock? Will that fit on the kxt or would it be too long??

It's probably a little too long. Not sure about reservoir mounting either. Clean your Tecate shock up and send if off to a suspension rebuilder.

The igition system you say is different but better.
How so???

The KX ignition is a much more robust system designed for racing. On the Tecate Kawasaki chose to glue the magnets to the flywheel. Over time, the glue can fail and if you strike the flywheel when removing it you can knock the magnets off. I found out first hand on my 84 KXT years ago that if the main bearings start to go bad, the extra rattle caused can shake the magnets off the flywheel. The KX flywheel is smaller and the magnets are bolted on. If you go with a KX ignition, you need to run the whole thing: flywheel, stator, coil, and CDI.

Would a newer kx motor fit in????

I think this was answered in the posts above. But once again, the only KX motor your using in an 84/85 Tecate with out rebuilding the front of the engine cradle is an 83/84 KX250.

Cause I see alot of 250's going pretty cheap. Like 1500 cnd for a 2000.
My buddy has my old T4 is getting ancy to drive it, and I want to own him.
And if the jug is that much better or the motor for that much. And unknown to the naked eye.?

Any kind of mod you make to a Tecate if done right will appear stock to most naked eyes. There's a guaranteed way to "own him". Leave the KX250 motor in the KX.

Where could I get a swingarm for it?

Best bet is to have yours extended. You might come across one on ebay or run a wanted add in the newspaper of the closest major city.

Good luck with your project!