Stock Moto / CR125 general info, parts availability?

After several years with a TAG, I’m thinking a lot of adding a shifter kart to the mix. I don’t really care about racing it, and I know a lot of people are going to say to go with a Rok Shifter or a KZ or even an CR80, but for whatever reason I’m feeling very partial to the CR125.

That said, I also don’t want to paint myself into a corner. My main concern is parts availability. Please share your knowledge in this area (what’s hard to find, how hard is it to find, etc) along with any other worthwhile kart specific CR125 resources/info. I feel encouraged by the number of CR80 owners that keep their stuff running after all these years, of which there are a lot of in my local area, but it would be good to hear some positive things about the 125 in this regard. Thanks!


Hard to find a place to race an 80. I LOVE them, but they’re very niche.

You’ll probably always be able to get oem spec aftermarket parts for the cr125, but depending on the ruleset you’re running under, it may be illegal to use.

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There are actually a ton of 80s in my area (Northern California). There’s a group of about twenty of them that have gotten together and created their own series which visits a few of the local tracks as part of their schedule. If I cared about racing it that would be the obvious choice, but I don’t, and I want something that is significantly faster than my TAG and a KA. :slightly_smiling_face:


Also, how altered is the common kart CR125 from one coming straight out of a dirt bike? I ask because that seems like an obvious source for a spare engine, but maybe it’s not so simple.

It depends a lot on the year. Not all bikes had the six speed transmission, cases older than 97 are a little different and of course you have the <99 >2001 cylinder thing.

Are you thinking of running a spec moto class, or just a keeping one running for turning laps.

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80’s are slow. Still fun to drive, but if part of your motivation for adding a gearbox kart to the mix is speed then I’d look at a 125.

I’m shocked that I beat Charles to the punch here, but the YZ125 that Factory Karts just announced is an intriguing option here.


Just turning laps with it (probably). So while I try to keep my stuff in race-like condition, I won’t actually be too worried about the legalities of any particular ruleset if push comes to shove.

I was assuming that I would need to stick to 99-01 just because that seems to be what will be most compatible with karting. I would love to know all the background on the CR125 and all the little gritty details of the package/class, but I’ve figured out that the best documentation for all of that stuff probably died with ekartingnews old forums (and understandably there’s not much info here on it because the package has pretty much dropped off the radar in modern times). In fact, I’ve just spent a couple of hours in tonight trying to figure out how to scrape the shifter forums archived there, lol. Have the beginnings working, but not completely there yet.

Regarding the new YZ125 from Factory Karts - would love everything about it except the price. A not-small-part of my interest in the stock moto is their price given that I’m not so worried about racing it. :slightly_smiling_face:

Caleb, I run a 99 CR125 in Long Circuit/Road Racing (in SE Australia). Been doing so since 2016 in our Stock Honda class.

We can still get top and bottom end parts without an issue (I get mine from Shark Shifter, albeit at an outrageous shipping cost). But outside of that, I have heard problems from others on more specialised parts. We are having a “debate” within our Club on alternatives (I’ve been testing the Euro 175 SS, which with some carb lessons is really beginning to perform and match the CR125 on tough WOT road circuits), but the matter is miles from resolved (there are loyal supporters, for good reason, who don’t want to see change). I’d be keen to hear what others have to say on the subject. It certainly feeds into the discussions we’re having here.

Other than for the parts uncertainty, and zero building of new engines over that last four years or so, we had access to AvGas (our low level lead choice) cut in mid 2019 due to changed Australian Federal Government regulations (don’t get me started on whether they had the constitutional right to even change the system). From that point we’ve had plenty of issues running the no lead alternatives, whether VP or Elf 102 - countless seizes, but just not me. Detonation for me though has been a problem. I was using a main jet down to a 175, or maybe lower, using AvGas. I now have to run 200. Some run higher again. Was running a 190 with the new fuel and still managed to stuff my barrel via detonation around the top edge.

Keen to hear what others have to say on parts availability.

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Not on topic here, but have you tried backing timing down? Should help with the detonation I would think.


I know it’s subjective, but I disagree. Sure on time, a 125 is faster, but things happen pretty quick on a 80 and ringing the absolute neck out of one is SUPER fun.

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For parts availability: there isn’t any. Honda got out of the two stroke business sixteen years ago.

An 85 is a good matchup for an X30 on speed. It’s certainly a higher pilot workload.

The SSE175 needs 105+ octane fuel to be lean and happy. Avgas is 108. If you want a good 175 kart I have the LAKC pro ahifter championship winning kart available.

If you don’t want to spend New Factory Karts Z125 money, just go get a TM. K9B, K9C, KZ10, whatever - they’re really good at building kart engines.

For sure they’re fun, but I think back to my first ever shifter kart experience where I hopped in someone’s 80 at NCMP. I was racing Tag at the time, and remember being disappointed with the speed of the 80. First time a drove a 125 (stock honda) was a whole other animal…best thing I had ever driven!

I have seen some used CR125’s out there. If aftermarket parts have the same longevity as the OEM ones then it’s a no-brainer in terms of bang for the buck.

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I think you hopped into the wrong 80… :grin:

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Could be! It’s too late now either way as I’ve been spoiled by KZ :drooling_face:

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I was going to say, at a typical 80 weight and a motor tuned for kill they are pretty fast and can mix it up with a 125.

Anyway, this is a 125 topic… I like to think of parts availability as being situation specific influenced by supply and demand. That’s to say, for situation number one: Honda\HPD pulling the plug prettymuch was the death knell for it as a widely adopted class.

But for scenario two, a weekend or weekday warrior… I think you’ll be able to poke around the internet and find parts to keep it ripping for a long time. In that situation I’d have zero concerns about running one and some of the deals I’ve seen recently are VERY tempting.

Heck you can still get parts for the 100cc direct drive aircooled engines that have not been made since the 90’s.

I will add though that the CR125 still has strong support as a class in segments in road racing.


iv been so many hours on those engines throw dirt bikes honda cr 125 here in europe ,

got my first bike at 1989 , then switch to a 1992 then to 1996 and last engine was a 2002 . it is a beaty to ride and a bulletproof small japanise warrior , never let me down all this years , never blow up a piston or a crankshaft , even in the lean side of tuning .

the bad news for as here is that in karting they wasnt ever available to buy . as a last word to bring some more colour to the thred im bringing this doc that always get me so emotional with the CRs .

even if this is somekind of a dead category now . this engine got that something for me .

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A lot of the value of stock moto as a class was diminished when there was a temporary shortage of 99 cylinders.

The previously not permitted 2001 cylinder made more power, was more expensive to buy due to the extra difficulty of blending the power valves and finally… they were more prone to detonation.

Once the 2001 cylinder came in, there was no going back.

The road racing classes are typically 99 only.

James, thanks for the commentary regarding the 2001 cylinder. I’ve been wondering what the differences are between the 99-01. Btw, what about a 2000 cylinder, I never see anyone mention it (same as 99??). Also, you bring up some good points about people with more obscure engines than the CR125 still figuring out how to do it. (I had an HPV up till about 4 years ago, and currently have a fleet of PRD Fireballs, haha)

Thanks everyone else with the feedback. Fairly promising for the most part!

Good question. My engine builder hasn’t mentioned it, but I’ll ask. We do have a required timing plate installed, so not sure whether that just restricts further advance or also limits backing the timing down too. Outside my pay grade, but I’ll check.

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Stamatis, I think you want a Factory 125. Come on out to Riverside!