My latest video is up looking back at Yamaha's 1992 YZ125

As always, nice review man!

That was one of my favorite bikes as a kid, handled so well and was so fun to ride. Similar to riding a pit bike.

Unfortunately when it came time to race the '92 usually stayed in the garage and I loaded up my tired '90 model. Or I just didn't bother with the 125's and just raced my 250.

I miss how bikes looked in the 80s and early 90s

thanks blaze!

That bike was so slow that Yamaha was paying $500 in contingency to win the 250C class at local races like CMC back in the day.  Good times.

This bike was amazing on paper. 

It looked great. It turned on rails, had great suspension, and good dyno power.  It was cleverly ergonomically considered and bulletproof... 

And it just was so slow. 

I don't think we even have a concept in the 4-stroke era where good power, handling, suspension could apply in concert to form a tragically slow bike. 

I can only assume it was specifically this two-stroke bike that had Japan executives pulling their hair out and demanding that the AMA ban this shit for good so they could get back to designing efficient outboard motors...

So that's what I will mark it: the bike so singularly well engineered that the Japanese just fully said "screw this" on 2-strokes.

Maybe the OEMs just go by numbers sometimes and never ride the thing (or read any reviews of it). Amazing that Yamaha just didn’t care for those years. Didn’t Bradshaw say that he didn’t want to ride the 125 in the mxon?

It kind of shows the Japanese mindset sometimes - very stubborn. In fact, Mr.Honda was so dead set against 2-strokes back in the 70s, that the engineers worked on one in secret.

I thought the bike was also plagued by crappy machining tolerances. Heads with mismatch volumes same with the ports and power valve matching. Along with the reeds flexing too much. 

So no one bike ran alike stock and why places like noleen etc. Made so much from modding these bikes. From what I understand once you cleaned up the tolerances. It ran pretty decent. 

It's why dirt bike or dirt rider was shocked how poorly it ran. Because a few months earlier they rode pre production bikes that ran so much better than what was coming stock.

The 1992 YZ 125 was so slow that Doug Henry on the satelite DGY "B" team rode the bike to a 4th place overall series finish and was awarded with a factory Honda ride for 1993 and smoked everyone for the championship. Who built those engines for DGY, anyone remember?

Or maybe all bikes have whatever machining tolerances and there's always ones off the assembly line that are faster and closer to spec than others, but it is only when the model is dog slow that every kid's dad starts pulling out those micrometers.

were the 94s any better? I acquired 1 back in 2001 needing new top end but never got around to getting it running. Now it looks too tall for me and can't decide whether to get it going or move it along as-is with all the parts I bought for it.

Are you planning to race your '94? Because if you didn't gather, the '92 was a really good motorcycle, just not a preferred racebike.

Emig won a national championship on it. The DGY bikes were comparable they had a lot of help from Yamaha. It was just slow in stock form, once they modified the carb, used heavier reeds, ported the cylinder, fixed the squish, modified the power valve and tuned the PC exhaust to all of that it was okay! I had dinner with both Henry and Button and the team before the Dallas SX in '92 and had tons of questions about the pro bikes.

no, my racing days are behind me. When I got this 1 25 years ago I was big into VMX and really motivated to get it going. Now at 68 with 2 replaced knees and back problems the desire isn't there. Also, I have short inseam and this thing is TALL in the rear end- like top of seat is about belly button level standing next to it. I actually have an 87 YZ125 that fits me a lot better that I plan to refresh in the short term. Time to move along the overflow I'll never get to and they just sit.

The 94 was the new engine redesign first year. Where they went away from the ypvs drum to the guillotine setup. Better than the old design but still mostly a mid range bike stock. 

Back in 94/95 teams found out if you opened up the ports it made much better power. So in 96 yamaha basically did just that and made the power valve bigger. More surface area bigger opening. Which we all know from 96 on yz125s have ruled. 

Lots of the bottom end parts typically fit 94 thru 04. 

Get that thing together and ride it. It was a really fun bike. Back then, we considered anything that didn't yank your arms off in the corners too slow. You're probably not looking for that anyways.

Half of vet riders are looking for the best way to put YZ suspension on their TTR125. 

My ported 92 ripped while my friends 91 was clearly slower. Nice chassis.

I have a build coming with a 97 engine.

Honda's ate them for breakfast 

I picked up a '92 WR200; from what I have gathered, it is based off the YZ 125 chassis from the same era. Am I correct in recalling that DeVol Racing had an improved linkage setup for YZ's of this era? With an FMF pipe, I have no complaints about lack of power, but am interested in options for upgrading the suspension. 

i had that bike, it was so reliable - i never had so much riding time on a bike without major issues.

But i also realised how slow it was stock compared to my friends 1990 CR125

i put an pc exhaust on it and the bike was a screamer, when i put boyesen reeds in it- it was a total different bike- power from the bottom to the top was significantly better.

I regret selling this exact bike- i must have had around 40-50 MX bikes at least.

I had a 1993. Rad valve and dealer accessory YZ-R pipe (which I think PC made?) made a huge difference.

We might need pics of this one 👍

The 91 was such a dog, even lightly modded, that the '92 was a rockstar in comparison.  Even straight off the showroom.