1981 YZ125H modified vintage racer

Dick Trickle 2/17/2015 12:03am
2/17/2015 12:03am
newmann wrote:
That's a replica of a works Yami silencer. Considering the pressed and formed end cap and brackets along with probably an aluminum core and all that...
That's a replica of a works Yami silencer. Considering the pressed and formed end cap and brackets along with probably an aluminum core and all that other sweetness, $375.00 is a pretty good deal. I paid more to get a one off 100% correct hand made replica out of steel for my RC500. That pipe there is probably $1000.00....Sick So trick!
GIwasB4 wrote:
I don't feel so bad about this then. 4 times that deal. [img]https://p.vitalmx.com/photos/forums/2015/02/14/80268/s1200_1980yz125_exhausts.jpg[/img]
I don't feel so bad about this then. 4 times that deal.


newmann wrote:
What's all that trickery for? Who made, Holley? I remember the days I would buy three of everything...lol
They look very similar in build and quality to the Jon Easton (JEMCO) pipe i had made up for my 83 YZ125K that is going on my Lechien tribute bike. It was only $300 hand built... i thought that was a great price for a great pipe..


Also, in regard to the question i posted up about a basket for an H.. there is a mob making billets ones and selling them on Ebay here...http://www.ebay.co.uk/itm/YZ125H-Billet-Clutch-1981-/201285030809?pt=UK…
Look like this..



Dick Trickle 2/17/2015 11:56pm
2/17/2015 11:56pm
Nice photo there Reece. Do you have any of the 83 OW125?
Mike P.
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Mike P. 2/18/2015 2:40pm
2/18/2015 2:40pm
I used a Vintage Iron pipe, which costs me under $300.00 and looks the part, but it took forever to arrive.


Dennis_Fitzpatrick 10/18/2017 7:35pm
10/18/2017 7:35pm
rob.boucher.547 wrote:
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...
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
I have a question about the placement of the top seal on the 81 yz125H steering stem. My son and I are restoring my YZ125H and I have forgotten where that upper seal is placed on the stem. Would you happen to know the position of this seal. We cleaned the surface rust off with a brass wire wheel, so there are no marks where it had been positioned.

The Shop

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lumpy790
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lumpy790 3/28/2018 8:43am
3/28/2018 8:43am
rob.boucher.547 wrote:
[img]https://p.vitalmx.com/photos/forums/2013/07/16/27229/s1200_image.jpg[/img]
amazing looking YZ!

Since you have knowledge doing vintage restorations..... I have a question for you.

I have always wanted to make new silicone hoses for the 1981 YZ125 and the 1982 also since they are different.

What do you think? Thinking just making them in Black.
lumpy790
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lumpy790 4/17/2018 8:29am
4/17/2018 8:29am
I have been Collecting all the 81 YZ125, 82 YZ125 and 82 YZ250 hoses and radiators to manufacture them.

Ended up buying one radiator and a hose and they really mangled up the radiator to twist the fitting so they could run a long hose up to the top.

I am debating on also making a kit with both the radiator and different hoses that eliminates going through to top triple clamp. What do you think?
GIwasB4
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GIwasB4 4/17/2018 12:42pm
4/17/2018 12:42pm
lumpy790 wrote:
I have been Collecting all the 81 YZ125, 82 YZ125 and 82 YZ250 hoses and radiators to manufacture them. Ended up buying one radiator and a...
I have been Collecting all the 81 YZ125, 82 YZ125 and 82 YZ250 hoses and radiators to manufacture them.

Ended up buying one radiator and a hose and they really mangled up the radiator to twist the fitting so they could run a long hose up to the top.

I am debating on also making a kit with both the radiator and different hoses that eliminates going through to top triple clamp. What do you think?
Effectively eliminate the triple clamp routing? I'd be in for a set or three.
I'm not talking just running the hose between the fork tubes and steering stem. How would you do it?
lumpy790
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lumpy790 4/18/2018 2:20pm
4/18/2018 2:20pm
lumpy790 wrote:
I have been Collecting all the 81 YZ125, 82 YZ125 and 82 YZ250 hoses and radiators to manufacture them. Ended up buying one radiator and a...
I have been Collecting all the 81 YZ125, 82 YZ125 and 82 YZ250 hoses and radiators to manufacture them.

Ended up buying one radiator and a hose and they really mangled up the radiator to twist the fitting so they could run a long hose up to the top.

I am debating on also making a kit with both the radiator and different hoses that eliminates going through to top triple clamp. What do you think?
GIwasB4 wrote:
Effectively eliminate the triple clamp routing? I'd be in for a set or three. I'm not talking just running the hose between the fork tubes and...
Effectively eliminate the triple clamp routing? I'd be in for a set or three.
I'm not talking just running the hose between the fork tubes and steering stem. How would you do it?
By not passing the through the triple clamp it will put a lot of stress on the hoses having to bend back and forth over time so I do not know how long it will last.

The radiator I bought still seemed to use the bottom hose through the triple clamp route but the top was run simulator to this Kawasaki 3 wheeler.



dcfitz
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dcfitz 11/3/2018 12:42pm
11/3/2018 12:42pm Edited Date/Time 11/4/2018 7:28am
Speaking of 1981 YZ125H bikes, I reciently restored mine with my son, does anyone know what the proper top steering stem seal placement is on this bike? All the pics I’d seen had it placed below the hole in the inner stem, so that’s where I installed it. It’s leaking at the top of the steering stem, now, when I ride it.
1
dcfitz
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dcfitz 11/10/2018 9:57am
11/10/2018 9:57am
I think I solved the issue. When I rode it, it felt like the steering stem was a little loose. I tightened everything up and it seems fine, now.
barnett468
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barnett468 11/10/2018 5:48pm
11/10/2018 5:48pm
Shawbridge Husky wrote:
Any way we can PM you Rob ? There's some stuff that's not worth my time doing as you are already up to speed and better...
Any way we can PM you Rob ? There's some stuff that's not worth my time doing as you are already up to speed and better at it anyway. Maybe I can help you out with EDM, CNC, HT or laser marking that you are not into doing. Send me a PM with your contact info please if you may. Would appreciate. Good tips on Broc's '80 125 LQ, pretty cool with the tooling situation history at Yamaha to make to H happen !

PS : Where can I see more photo's of your vintage Bombardier sleds ? I spied a pic of which is probably your TNT RV free air I think. Not that I would ever think of building one, just that your overhauls are eye candy to me.
I sent you a pm.

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barnett468 11/10/2018 5:50pm
11/10/2018 5:50pm
lumpy790 wrote:
I have been Collecting all the 81 YZ125, 82 YZ125 and 82 YZ250 hoses and radiators to manufacture them. Ended up buying one radiator and a...
I have been Collecting all the 81 YZ125, 82 YZ125 and 82 YZ250 hoses and radiators to manufacture them.

Ended up buying one radiator and a hose and they really mangled up the radiator to twist the fitting so they could run a long hose up to the top.

I am debating on also making a kit with both the radiator and different hoses that eliminates going through to top triple clamp. What do you think?
GIwasB4 wrote:
Effectively eliminate the triple clamp routing? I'd be in for a set or three. I'm not talking just running the hose between the fork tubes and...
Effectively eliminate the triple clamp routing? I'd be in for a set or three.
I'm not talking just running the hose between the fork tubes and steering stem. How would you do it?
lumpy790 wrote:
By not passing the through the triple clamp it will put a lot of stress on the hoses having to bend back and forth over time...
By not passing the through the triple clamp it will put a lot of stress on the hoses having to bend back and forth over time so I do not know how long it will last.

The radiator I bought still seemed to use the bottom hose through the triple clamp route but the top was run simulator to this Kawasaki 3 wheeler.



I did all the development testing on all the tecates when i was a project manager at kawasaki in the r and d department.

1
dhargreaves120 6/17/2020 8:46pm
6/17/2020 8:46pm
Awesome build Rob! I’m thinking of doing exactly this to my 125H.
Did you use heavier fork springs to match the 465 rear that you used?
Thanks
rob.boucher.547 6/23/2020 7:15am
6/23/2020 7:15am
yes, bought a new set from racetech for my weight
replaced the rear shock with a custom hardcoated
NJ6 shock
The bike sold a few years back to a private collector
out west to sit on display with his GT40's, Ferrari's
and a half dozen bikes he has purchased from me.
2
dhargreaves120 6/23/2020 3:54pm
6/23/2020 3:54pm
rob.boucher.547 wrote:
yes, bought a new set from racetech for my weight replaced the rear shock with a custom hardcoated NJ6 shock The bike sold a few years...
yes, bought a new set from racetech for my weight
replaced the rear shock with a custom hardcoated
NJ6 shock
The bike sold a few years back to a private collector
out west to sit on display with his GT40's, Ferrari's
and a half dozen bikes he has purchased from me.
Thanks Rob, it’s pretty much exactly what I want to do to my 125h. Works bike on a privateer budget!
dhargreaves120 8/12/2023 10:45am
8/12/2023 10:45am
rob.boucher.547 wrote:
The 81 H bike is based on that Broc glover engine an exact copy, only die cast, run with a right hand exhaust, 34mm carb Brocs...
The 81 H bike is based on that Broc glover engine an exact copy, only die cast, run with a right hand exhaust, 34mm carb
Brocs bike ran a 38mm carb
I have other close photos of the #1 champ bike, and the H is not far off that bike
Video the 125gp in ohio , The Great minnesotan Tommy Benolkin raced also

Hi Rob,

Great build, I'm just starting out on my125H rebuild / restification. Yours is exactly how I'd like to do mine.

What size carb are you using? I'll be replacing mine as whoever jetted it must have used a hammer! 

Thanks

rob.boucher.547 8/14/2023 6:38am
8/14/2023 6:38am

stock carb, stock jetting, 2 up on main jet, old post, bike is long gone, sitting on a display in UTAH

gavan
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gavan 10/28/2024 6:37pm
10/28/2024 6:37pm
rob.boucher.547 wrote:
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...
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

you mentioned you decked the cylinder, what was taken off (or added but i think it would be taken off) and what was the effect pls.

Thanks

Gavan

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