1981 YZ125H modified vintage racer

Edited Date/Time 6/23/2020 3:54pm
Here is a pic of my 1981 YZ125H VMX racer
I removed about 10lbs off of the total weight
With the modifications.
Race tech suspension, lots of aluminum parts, and
Titanium custom machined bolts, bushings
2
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7/16/2013 6:27pm
that really nice!
i would like to do something similar with my 1982 yz125j
PN27416
Posts
1019
Joined
6/12/2008
Location
Coopersburg, PA US
7/17/2013 7:33am
Nice job, where was the show?

The Shop

7/17/2013 8:15am Edited Date/Time 7/18/2013 6:08am
Mn state fairgrounds
Early morning before show building filled up

About 200 plus bikes at show
2
mb60
Posts
4752
Joined
3/7/2010
Location
GRAPEVINE, TX US
7/17/2013 3:29pm Edited Date/Time 7/17/2013 3:30pm
Awsome job on the resto. A safety seat always made them look a bit tricker in my opinion.
The Sneak
Posts
169
Joined
2/24/2009
Location
US
7/18/2013 6:18am
nice job!
can we have more details on the build?

For example, I know a lot of guys like to run 43mm forks and DLS front brakes from a slightly later YZ250/490. Are you running emulators? Tell us about the rear shock - does it have that trick multi-rate spring?

How does it feel vs a stocker not only from a suspension standpoint but weight and top-heaviness?

the engine - tell us about the build

Sorry - I am a YZ fanatic and was frequently one of the only YZ80/YZ125 mounted guys in my class in the early 90s around here.
DoctorJD
Posts
2922
Joined
4/1/2008
Location
Somewhere in..., GA US
7/18/2013 7:28am
Beautiful resto! That bike brings back so many memories, those 81's were so trick for their time, it was like owning a factory bike. If it only performed like one.
7/18/2013 8:12am Edited Date/Time 11/19/2013 8:00am
No, i do not recommend installing 43 mm forks on
The 80-81 bikes
The extra lbs would be a disadvatage. the overall goal was to
Reduce weight and improve handling
The stock 38 mm forks were the best 38 mm kyb
Of the day
The braking plates have been modified with
Bronze bushings on the cam's for extra power
(No play) and pressure

Engine
Cylinder ported, decked
Crank pin bored ,stuffed
Crank halves bored , stuffed
Transmission cut, polished, mil spec dry film coated
Barnett clutch parts
Head reworked
All bearings replaced
Kicker remanufactured
With A2 pin(drilled thru)
All screws replaced with
8mm Honda hex bolts
Wiseco piston
I am sure i forgot a few
More things

Hand machined shock
Res, with a high flow
3/8 id hose, cooling fins,
Standard air valve

Race Tech Gold valves(front / rear)
YZ465 spring
1
10/28/2013 10:03am
all steel parts replaced with billet
axle spacers/ Ti axle nuts
bearing spacers
Ti footpeg bolts
modified chain guide plate
Trick steering stem
Pro-form exhaust
modified air box/ new trick box hardware
New carb
reeds/ boot
10/28/2013 10:06am Edited Date/Time 11/18/2013 7:14am
Hand machined rear brake stay, hand machined bronze bushings
Titanium bolts
Titanium foot peg mount bolts
11/18/2013 7:05am Edited Date/Time 11/18/2013 7:12am
titanium fuel tank bolts, titanium exhaust mount bolts, fuel tank bushings, side plate washers
all hand machined , one at a time
1
11/19/2013 9:55am
Great job on the bike and parts Rob, feels good to make those parts yourself doesn't it?
MaxPower
Posts
2647
Joined
8/15/2006
Location
NJ US
11/19/2013 2:31pm
You look to have your front number plate sorted already, but I have a vented Cycle Am front number plate like Hannah ran on one of his early on the forks radiator 250s and a unvented plate too that you are welcome to for this bike. I hated those Cycle Am fenders . Hannah must have been paid a lot of moniey to run those hideous things
11/20/2013 10:12am
rear hub was completely remachined with 4000
series steel inserts pressed , staked and bored for
a super strength bearing bore, then Al/ni/brnz sleeves pressed
over the od of the hub add even more strength to the bearing
area

1
11/20/2013 10:23am
I have been recieving emails weekly about the bike
so this is a great place to post info on the bike
so i do not have to reply to all the emails

The frame was modified for strength, and
for ease of assembly.

I still have not made the trick skid plate i have
on the drawing board, with a few other items
BigAl
Posts
266
Joined
7/7/2012
Location
Prichard, WV US
11/20/2013 11:23am
I wonder if the steering stem/cooling/hoses could be reworked like the early cagivas?
11/20/2013 2:01pm Edited Date/Time 11/20/2013 2:02pm
My steering stem was remachined, and bronze
sleeves (seal area) installed, remachined back to a slightly
oversize for more pressure on the seal lips
and dry film coated for a corrosion proof life
I also doubled up on the upper seals

I did three separate stems, so i have extra's
ready to go
2/14/2014 4:31pm
pete24 wrote:
very nice
Hello
I have yamaha yz 125 h (4v2) 1981
I need fork bushings : two bushings covered inside ( 38x42x12mm )
and two bushings covered on the outside ( 37x39x20mm )
Measured when squeeze bushing
Please help please write back
for example
danio8522@gmail.com
2/14/2014 7:12pm
order suzuki 1980 RM250 fork bushings
or 81
they are 7.00 each top , 10.00 each bottom
versus $40.00 each yamaha price
same kyb parts
2/15/2014 6:53am
Are you could post a link to the web page in fork bushings becouse I will have not certainty these are the good parts
2/15/2014 11:34am
I have in mind you wrote a link to an online store. I could buy good fork bushings to yz 125h 1981 (4v2)
2/15/2014 3:05pm
No link to online store
You choose your Suzuki parts supply house
all kyb bushings(metal slides,or pistons
interchange from 77-85?

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