Two Stroke Motocross Forum => Photos & Videos => Topic started by: citabjockey on June 19, 2011, 04:53:40 PM
Title: Vintage Yamaha 125 - now a 175!
Post by: citabjockey on June 19, 2011, 04:53:40 PM
I have a 1976 MX125 yamaha. I just completed a conversion to 175 by swapping in a DT175 top end. This was a true bolt on proposition and turned a very lightweight vintage motocrosser into a really nice trail bike. Anyway here are a couple of shots of the bike:
Title: Re: Vintage Yamaha 125 - now a 175!
Post by: citabjockey on June 19, 2011, 04:59:15 PM
And here is the first session on the new motor from yesterday!
There are still some issues but I am amazed at how well it runs. I now have a touch of grunt on the bottom end and a smooth transition to what is still an adequate top end. All with teeny tiny ports from the enduro cylinder.
http://www.youtube.com/watch?v=Wd6kqQP1wJ0
Title: Re: Vintage Yamaha 125 - now a 175!
Post by: SachsGS on June 19, 2011, 06:44:22 PM
Ah, those were the good old days! Almost everything was interchangeable and inexpensive to boot.I wonder if an IT200 top end would bolt onto those cases,that would give you some power. ;D
Title: Re: Vintage Yamaha 125 - now a 175!
Post by: citabjockey on June 19, 2011, 07:31:50 PM
I was actually looking for less power. This was kind of an experiment to see if it can be turned into a good learner bike for my daughter. So far I have quite a bit less $ into the bike than a used ttr125. So I thought if it had the 175 enduro power which is very low end centric and still weighed 180 lbs and has a nice low seat height it would fit the bill. So it worked in that the engine does have some off idle power like I wanted but that mx expansion is somehow getting a fair bit of power out of those dinky enduro ports. Too fast for a learner bike. That's ok, it's a blast to ride!
Ah, those were the good old days! Almost everything was interchangeable and inexpensive to boot.I wonder if an IT200 top end would bolt onto those cases,that would give you some power. ;D
Title: Re: Vintage Yamaha 125 - now a 175!
Post by: SachsGS on June 19, 2011, 09:27:09 PM
Seeing as you are a fan of the vintage Yamahas, the TY175 was probably one of the best learner bikes ever made (one of the most durable as well!). ;D
Title: Re: Vintage Yamaha 125 - now a 175!
Post by: ACMX on June 19, 2011, 10:23:34 PM
Haha. Looks like its got more bottom than my 125.
Title: Re: Vintage Yamaha 125 - now a 175!
Post by: EJ on June 20, 2011, 02:01:05 AM
Nice bike, reminds me of my old YZ 50, i still regret the day i sold it... Nice memories from a lovely era.
Title: Re: Vintage Yamaha 125 - now a 175!
Post by: WoodsRiderParts on June 20, 2011, 05:53:16 AM
I had one of these awhile back. I forgot how simple they are, and how easy they were to work on. A lot of people did that back in the day with the 175 top-end. It completely changed the bike and the power by adding that 175 cylinder!
Title: Re: Vintage Yamaha 125 - now a 175!
Post by: Coop on June 29, 2011, 05:19:58 AM
Good looking bike. I used to have an MX175 as a teen, it was a good bike.
Title: Re: Vintage Yamaha 125 - now a 175!
Post by: MyckMcClung on June 29, 2011, 06:48:47 AM
sounds strong, but it looks as if you're getting a serious kidney massage :P
Title: Re: Vintage Yamaha 125 - now a 175!
Post by: citabjockey on June 29, 2011, 11:28:18 AM
Quie correct. The suspension is pretty stiff and iI think has 6 inches and change travel in the front and even less in the back. That said it is an absolute blast to ride. I did some more work on it over the past few days fixing things, installing a better air filter and a new clutch. Hope to take it out on Saturday once again.
sounds strong, but it looks as if you're getting a serious kidney massage :P
Title: Re: Vintage Yamaha 125 - now a 175!
Post by: ford832 on June 30, 2011, 05:36:29 PM
Very cool.I remember them well as my next door neighbour in Ontario rode one-then the 250 then the 490.I was the 5 yr old kid on the other side of the fence drooling at them. :)
Title: Re: Vintage Yamaha 125 - now a 175!
Post by: riffraff on July 05, 2011, 09:50:07 PM
I've had a '72 CT1 175, '74 AT2 125 and a '76 YZ175C. The '76 YZ175 was the first year the top ends weren't interchangeable. The '74 AT2 had an electric starter. . . . I always liked that paint scheme and metal tank on the 76's
Title: Vintage Yamaha 125 - now a 175!
Post by: citabjockey on August 08, 2013, 05:18:41 AM
Did some more jetting work and replace main seals on this "175" over the past few weeks. Also put some fox emulsion shocks on the rear replacing the stiff-as-a-board KYB gas shocks (that may be from a TT500). Rear end works much better.
got a chance to ride it yesterday. Here is video of a couple of hills in my riding area. 3 minutes into the video you can see why I wanted the 175 hardware in the engine -- I blow a shift but can still make the (snotty) hill!
Title: Vintage Yamaha 125 - now a 175!
Post by: _X_ on August 08, 2013, 09:56:11 PM
nice vintage friendly moto track there citab, looks like a good place to rip the vintage.