crickets

I'm fortunate to live in Florida and our Club, Sunshine State Vintage, voted last week to have classes by year - 75 and older, 76-79, 80-85, 86-89 and 90s and then modern. They have others classes too,,but this excites me to get the KX ready to battle with a friend and his 83 CR125,with mugen topend.
I just had my cylinder plated,,,but on closer study and research I found out my cylinder is 82 not the original 83. So I'm looking for 83 too.

What is the difference between the years?
Is the exhaust port bigger on the 83? Every cylinder that i have looked in had a casting mark in the exhaust port that looks Iike a crack. Its the only thing on those old bikes that looks like a crack and isnt one.
I don't have much ride time on my bike but i was really pleased with how well it ran. Its has a fresh plate with cleaned ports and a Black Ops coil.

Those early disc did work a bit better than a DLS, but they were early in production, so if I had to guess as to why AHRMA has banned them (other than for the obvious reason…it's a disc) I'd say its because they know that someone would find a way to make them work better (increased stopping power) and then there would be a real difference between the DLS & the early disc. Just my guess, but think about it, 38mm forks are almost a thing of the past in PV racing as most use for most use 43mm forks. And Fox air shocks were the best in the business in 79, but a pair of Works, Race Tech or Ohlins shocks work far better and require less maintenance. I hope you can see where I'm going with this. Bottom line, that disc can be improved and done right, it would be a huge advantage. I hope AHRMA does make these bikes legal because I would be all over it.

I agree with you to a point and applaud your reasoning because riding 125’s is all about momentum until you run into a course like Budd Creek that has a gnarly downhill that I can tell you from personal experience if you do have some type of decent brakes coming down that hill you won’t make the tight left hand turn…unless you are moving incredibly slow…a wise person once said, “brakes brake for a reason”…

Here's my cylinder. Note the upside down L shaped exhaust ports. 83 was trapazoids. Note the single bridge down middle of intake port. 83 had 2 bridges so center intake and boost port at top was open and not split in half. The combustion chamber is offset. I'm not sure if this is 82 or 83. There is no part number on cylinder that I could find,,so nothing easy to tell apart from outside. Only after researching 6 magazines and shop manual did I find one clear description of the port changes. The transfers are slightly different height in degrees per the one article too. 82 was a screamer...83 the changes adding midrange hit. Some of the differences can be corrected with lathe and grinder..but the intake can't be exactly duplicated because of bridge(s) layout. One side says race it starting October when season starts...otherside says flea bay it or save as spare until I find a correct 83. Anyone has picture of there head I'd appreciate seeing it.

If the guys writing the rules owned '83 KX125's you can damn well bet the rule would be different.

I received my new issue of AHRMA" Vintage Views" yesterday.
In it are published the new rule proposals for 2016. The 82-84's are being considered for inclusion in the Ultima classes.

Having owned and racing both 82-83 KX 125's back then, there is no comparison between the way they run.
The 83 was so much improved in the engine department over the 82 model.

The 82 had it's match with the YZ125J in the power department in 82.

For 83, no other 125 was even close in engine performance to the '83 Kawasaki. Made the 82 look like it had a rag left in the airbox.

Speaking of the airbox. I saw a trick 83 recently that had a white aftermarket airbox. Has anyone seen them before. I really want one. I've only seen them on RMs.

Project Racer,

Play Devil's advocate, I'd have to dig back into my old magazines, but I thought the 83 Honda CR125 was the best 125 that year according to just about every motorcycle magazine that tested these bikes? But, if AHRMA ever comes around I will certainly get an 83 KX125/KX250, and I'm not so much worried that the 83 CR125 is better, because I can find a way to make those KXs run at the front of the pack (we have 30+ years of knowledge and technology to work with)...

Also, I would not move so quickly to buy an 82-83 KX just yet, because AHRMA has done this before and not came through (a few years ago they were considering a class for front disc/rear drum and follow that with a class for bikes up to 1990 (if memory serves me correctly). So in anticipation, ran out and bought a 87 CR250 and the classes never materialized...Truth of the matter is that if you are in your 50s you really represent the last of the riders from the 70s. When I joined AHRMA, the majority of the riders rode vintage (pre 76) and now a lot of those folks have put the bikes down so if AHRMA is to survive, they will need to adopt these classes as the next group of riders whose earliest exploits started in the 1980s/90s are building/collecting and racing these era of bikes. I personally consider any bike made after 86 a modern bike (front/rear disc, case reed, etc...), and they can be made to go as fast as a modern 2 stroke per say in the right hands, but to many they are vintage bikes. I guess it's just a matter of when you born. I am over 50 so I can appreciate the difference between a disc vs. drum brake.

MXM, I am not a betting man, but if you swung a leg over my 1990 RM125, I feel certain you will walk away with a smile on your face as this bike has as much power (actually more) than your 03 YZ125 and will out handle it...trust me, you will be smiling. But really you are right, a 2003 YZ would best a stock 87 CR or even a stock 1990 RM125, but my point is that the major technology for these bikes basically stopped after 1986. The 87 CR125 like your 2003 YZ125 is a case reed motor. Upside down forks have been around since the early 80s, however suspension is the one area that continues to improve. 2 stroke motor technology reached it's greatest height in the late 80s. Yes there were improvements thereafter, but all the major changes to 2 stroke motors happened in the late 80s period. But, if you throw enough money at it, you can make it fast. But why would you...because you like that year of bike maybe? Who knows, but my point is that it can be done. In 1990 Suzuki had a superior frame design and while my 2005 YZ125 has an alloy frame, the design was very similar to that of my 1990 RM125 (take a look at the two bikes below and pay attention to the frame design (not the material it's made of)). My 1990 RM125 would run neck and neck with my 2005 YZ125 with PC pipe on it. I personally prefer steel frames to aluminum. I know alloy is light but it's also very ridged while steel flexes.

I have a older 78 RM125 tricked out that I raced in early 2000s in flat track on 1/2 mile ovals..I finished 2nd ,2 years in a row against the newest bikes each year. I battled up front against a new YZ125. For a narrow power range that rm makes equal or better power shown on that long track. The word is narrow..the new bikes would kill me if we where on a MX track with there wide powerbands.

As for the banned KX...AHRMA acts like all bikes where stock back then...Then and now everyone switches parts for aftermarket and other brands. If the disc was soooooo much better,,you could've bought the stuff from dealer or a parts bike and slid the 41-43mm forks and disc into your RM YZ or CR in 1982-1985. It fit back then just as it would today. Everyone was swapping carbs and reed cages, 82 RM heads onto 83s..ect, I even seen a RM DG head machined to work on a KX...It was period correct and available to everyone. I'm sure someone did swap KX forks and wheel onto there other brand...sure it was rare, but possible..but everyone poured money and work into engines as power was got you to the front.
Ahrma then turns there head when someone is using all this stuff that was made and developed years later!?
I'm glad I race in Florida where our new club Sunshine State VMX motto is for the riders, by the riders !

I agree with you Brian as that really sort of sums it up regarding AHRMA's position, and I also see MXM point, because he is correct, the eros did change by 1990, but if AHRMA allowed the 87 CR125, which had a rear disc, I would likely get one and could find a way to make it run against modern 125s. Yes the eros would not be the same (no flat seat or anything like that), but I could make the suspension work and the motor sing to keep up for sure (remember 144 is the legal cc now in AMA).

Mike P., while the 83 CR125 may have won the 125 shootouts, it was based on the overall package. Handling and geometry gave it the nod.

From the gate to the first turn, out of corners, and in the deep sand of Florida, the 83 KX romped all the other makes in engine performance.

I recall lining up with ex-Florida pro John Olten one night at a local race. I was on my '83 KX, and he had a new '83 CR125. I never made Pro, just local expert.

We finished our moto where I nabbed an easy holeshot, led him and the rest of the class around until about two laps from the end, when I nerfed it in a slow corner, letting him by.

We talked for a minute, and he said, "that bike is fast", referring to the KX. This is from a guy who had ridden Pro in Florida, and even quite a few 125 Nationals in '79.

The only mod I made to the KX was lowering the gearing. It was way over geared stock, IMO.

The 84 KX was even better.

1983 KX 125


1982 KX125

You know, I can see that. They said something similar about the 79 KX125 always getting to the first turn first, yet the 79 RM125 was the hands down winner that year in the shootout. I owned a 79 KX125 back in 2004 that was basically bone stock save a pair of Fox air shocks & heavier springs/PVC tubes in the forks and though I only raced it once at Dublin Gap in PA, I got 3 holeshots in my class that day (won both races) and that day we ran with the Ultima class and the only guy that took me off the line was an expert on an 83 CR125 (I was a B rider at the time), but I pulled him in the last race off the line and he chased me until the last lap where he finally passed me, but that little 79 KX held it's own, so they definitely had the power for sure. Here a photo from that race back in 04 and the bike.

If you want your favorite bike to be legal in AHRMA, and put mod restrictions on other bikes that may be a threat to yours, run for trustee, get in the click, and the AHRMA world is your oyster.

Does AHRMA still even hold races in MX ? As I raced dirt track with them from the early through mid '90's, they would get a fair turnout at Ocala, Daytona, Weedsport, the Ohio races.

I think it was nearly 170 entries for Ocala in '99, which is quite good for DT.

These days, the DT schedule is months late each year, and many races are TBA.

Lucky to get 5 riders in 250 Sportsman, when three heats of 12 riders was very common at one time.

Even 70's singles , which was an easy 4 - 5 heats of 10 -12, barely gets more than a handful these days.

You were not always guaranteed a spot in the main like it is now. No transfer finish in the heat, pack it up and go home.

Daytona AHRMA National 1994. 251-600 Sportsman ( modern vintage) class main. #74z Champion Yamaha MX360.

Mike, that is a neat KX125 you have there. I wish I would have held on to my '83. My dad sent it to me in the crate from Cycles Unlimited in Bakersfield ,California in early '83. Sold it to buy an '83 YZ250, and watched the kid basically destroy it.

My main rival in '79 used to do quite well as one of the few Kawasaki riders on a '79 KX250 in the 250B class. Those bikes had the gruntiest power delivery of all the 250's that year. Almost sounded like an open class bike.

Why did you get rid of the 79 Mike? I look back and can't figure out what i was thinking in 79 when i got a RM instead of a 79 kx125. They are such good looking bikes

Yeah...I regret having sold that bike, now a clean one will net an easy $4K almost...oh well...also that's an interesting take you have on AHRMA. Yes the rules or lack of change to them has influenced the attendance (at least in my opinion), but I think what's really driving the lack of participation is that a lot of people that raced and supported AHRMA even 7 - 8 years ago are no longer racing (these people are in their 60s & 70s now). 10 years ago you had riders from the 1960s representing (a lot of them are gone). Next you had the riders from the early 70s era (a lot of them are gone). Next you get to the guys in their 50s who raced from the mid 70s to mid 80s (like myself) and a lot of them are gone or racing modern bikes in Master classes. So what's left? the next wave, which are riders that grew up racing in the mid 80s - late 90s for which AHRMA does not really have a class or classes they are really pushing at the moment. If AHRMA is to survive, they need to rethink the classes and move toward the mid 80s - 90s bikes and I like the idea of racing bikes based on the year/configuration (i.e. the 82 - 83 KXs should be in the Ultima class based on the linkage suspension/watercooling) . Just my 2 cents worth...

I read the 83 had a 11t counter and the 82 had a 12.
The first two times i rode the bike i had an 11t i put the bike back together with. I just tried the 12 because i had it. The taller gearing for me made it a totally different bike. For the better.i cornered better and it barked through the gears with no problem. So im surprised to hear you say that it came too tall. If i was feeling better at Unadilla i was going to try a tooth smaller on the rear.

Kevin,

I got rid of the 79 because I was new to vintage racing at the time (I hadn't touched a dirt bike since 1990, so 2004 was my first year back) and everything I read or heard led me to believe parts for these bikes were scare. My bike was running good so I got rid of it before something happened. Looking back now things really were not that bad as was able to source a good top end/piston that year which I never had to use (still here at the house somewhere), but I was just too new to vintage racing and was taking no chances. That race in 2004 was my first vintage race and first motocross race since 89 as I had bought a 2004 KTM200SX that I raced one time at the VA state Hare & Hound, so I was really wet behind the ears in terms of knowledge regarding parts and the vintage MX community in general. But what a great little bike that KX was...

I have both 79 KX125 and KX250s...I dismantled both years ago and started resto on them but then I moved to Florida and they went into storage. I have some extra parts for both like frames,swingarms,pipes and misc. In case anyone else got one.
I had a 1983 CR125,,the MX and DB shootout winner and my feel was it was a nice bike...No it didn't have the raw power of my 83 KX125...but the KXs always got down-scored because of the forks needing work or gas tank shape and forward footpegs and handle bars swept back. My choice...I sold the CR and went looking for another KX. A couple years later the 1985 RM125 I was racing, owned by a shop, was highly rated for suspension and ergonomics...but the motor was a turd. My finishes sucked...so I bought a clapped out 83 KX with my own money and fixed it up and loved it. I was willing to go backwards in model years and sit a little funny if the motor ripped.
This all being said....if I'm on my rocket 83 KX125 with a front disc brake, and Tommy Benolkin is on a 1983 Honda CT70....place a bet on Tom for me. I won't throw the race...promise....but I'm sure he'll lap me...twice..even on a CT70 it's more about the rider. To me it would be fun to race a green bike again on a starting line of yellow and red.