1979 Honda CR125 racer build (lots of pics)

mxchris208
Posts
19
Joined
12/6/2018
Location
Sanford, FL US
Edited Date/Time 9/7/2021 10:54am
Here's a build that I did with my '79 cr125 to be a racer (yes, those are '80 side plates). Notable mods include: 21" front wheel, '83 cr250 forks, Noleens shocks, GMC exhaust, Moto Taz reeds, 36mm Mik, UFO carb flow ultimizer, Tom Morgan porting as well as bottom end repairs and tons of NOS items.




















12
|
PK97
Posts
253
Joined
7/28/2016
Location
Huntsville, AL US
8/23/2021 12:24pm
Nice build!
1
Pat327
Posts
649
Joined
2/18/2008
Location
CA US
9/4/2021 5:10pm
Such a clean build! Great work, she's a beaut!
1
9/5/2021 7:47pm
Nice job! Looks awesome! I have a tip for you on that airbox in which you may already be aware, but you can have it vapor blasted and bring it back to nos finish. I am doing (not lately however) an 81 YZ125-4V2 rebuild and my airbox had the same white scuff marks on the right chain drive side and I had my entire airbox vapored and it came back absolutely amazing. No more WD-40 or Meguiars Back to Black to subdue it, not to mention those kind of cover up products comes off after a wash job. Personally, I think it gives your build a nice ridden look and doesn't take away from the beauty. Just wanted to pass that along as a lot of people think vapor blasting is just for metals...

The Shop

mxchris208
Posts
19
Joined
12/6/2018
Location
Sanford, FL US
9/7/2021 5:57am Edited Date/Time 9/7/2021 5:59am
Nice job! Looks awesome! I have a tip for you on that airbox in which you may already be aware, but you can have it vapor...
Nice job! Looks awesome! I have a tip for you on that airbox in which you may already be aware, but you can have it vapor blasted and bring it back to nos finish. I am doing (not lately however) an 81 YZ125-4V2 rebuild and my airbox had the same white scuff marks on the right chain drive side and I had my entire airbox vapored and it came back absolutely amazing. No more WD-40 or Meguiars Back to Black to subdue it, not to mention those kind of cover up products comes off after a wash job. Personally, I think it gives your build a nice ridden look and doesn't take away from the beauty. Just wanted to pass that along as a lot of people think vapor blasting is just for metals...
I didn't know that. Thanks for the tip. I'm assuming set at low psi?
I do ride/race all the bikes I build bikes. It hurts to see them get scuffed or scratched up but I guess I just enjoy riding them more.
Years ago, my very first resto was a '81 yz125. That was a fun project. Unfortunately as soon as I finished it, it was stolen. Never even got a chance to ride it.
9/7/2021 10:54am
Nice job! Looks awesome! I have a tip for you on that airbox in which you may already be aware, but you can have it vapor...
Nice job! Looks awesome! I have a tip for you on that airbox in which you may already be aware, but you can have it vapor blasted and bring it back to nos finish. I am doing (not lately however) an 81 YZ125-4V2 rebuild and my airbox had the same white scuff marks on the right chain drive side and I had my entire airbox vapored and it came back absolutely amazing. No more WD-40 or Meguiars Back to Black to subdue it, not to mention those kind of cover up products comes off after a wash job. Personally, I think it gives your build a nice ridden look and doesn't take away from the beauty. Just wanted to pass that along as a lot of people think vapor blasting is just for metals...
mxchris208 wrote:
I didn't know that. Thanks for the tip. I'm assuming set at low psi? I do ride/race all the bikes I build bikes. It hurts to...
I didn't know that. Thanks for the tip. I'm assuming set at low psi?
I do ride/race all the bikes I build bikes. It hurts to see them get scuffed or scratched up but I guess I just enjoy riding them more.
Years ago, my very first resto was a '81 yz125. That was a fun project. Unfortunately as soon as I finished it, it was stolen. Never even got a chance to ride it.
A good reputable medium blasting facility will use different slurry recipes for different materials. While anyone can use wet silica on anything and everything, the results aren't as good as those company's who know how to mix different aggregates for different metals and polyethylene plastics to get the absolute best results.

For some small companies with one blasting cab, they tend to use a one slurry mix for all projects, so while you can still get ok to decent results, that's not the best way to do it. Choose a company that has several cabinets set up for both PE and alloys or one that will change the slurry to accommodate PE.

Some may argue that they can adjust pressure and distance to get the desired effect, so while that might be true in some cases, I want those who are willing to go the extra mile and that cares about my 40 year old parts enough to do it the right way. Anyway, I believe if I am not mistaken, the slurry mix that was used on my box was granulated walnut with around 55psi nozzle pressure. I will look for my old receipt and see if I can get you the contact number for these guys as this was done about a year and half ago.

OMG!!! That was you??? I remember reading about that. I believe you had a thread or mentioned it a few times on other 4V2 threads here at Vital. WOW!!! Unreal. I can only imagine the pain and suffering over that ordeal. Sorry to hear that was you my man, but it's great to see you are still doing and enjoying restorations. I love this 79 Elsinore rebuild. Have you checked out Hulk's CR500 thread from France?? INSANE!!!

Not sure if your up for making new friends from the internet after having a bike ripped off, but if you ever want to BS over these rebuilds and maybe let me pick you brain over the YZ, we can exchange emails or numbers or something, I might be able to learn something I haven't thought of...

Have a good one and keep up the pics, I love staring at these childhood friends of mine... LOL!!!
mxchris208
Posts
19
Joined
12/6/2018
Location
Sanford, FL US
9/7/2021 12:27pm
Nice job! Looks awesome! I have a tip for you on that airbox in which you may already be aware, but you can have it vapor...
Nice job! Looks awesome! I have a tip for you on that airbox in which you may already be aware, but you can have it vapor blasted and bring it back to nos finish. I am doing (not lately however) an 81 YZ125-4V2 rebuild and my airbox had the same white scuff marks on the right chain drive side and I had my entire airbox vapored and it came back absolutely amazing. No more WD-40 or Meguiars Back to Black to subdue it, not to mention those kind of cover up products comes off after a wash job. Personally, I think it gives your build a nice ridden look and doesn't take away from the beauty. Just wanted to pass that along as a lot of people think vapor blasting is just for metals...
mxchris208 wrote:
I didn't know that. Thanks for the tip. I'm assuming set at low psi? I do ride/race all the bikes I build bikes. It hurts to...
I didn't know that. Thanks for the tip. I'm assuming set at low psi?
I do ride/race all the bikes I build bikes. It hurts to see them get scuffed or scratched up but I guess I just enjoy riding them more.
Years ago, my very first resto was a '81 yz125. That was a fun project. Unfortunately as soon as I finished it, it was stolen. Never even got a chance to ride it.
A good reputable medium blasting facility will use different slurry recipes for different materials. While anyone can use wet silica on anything and everything, the results...
A good reputable medium blasting facility will use different slurry recipes for different materials. While anyone can use wet silica on anything and everything, the results aren't as good as those company's who know how to mix different aggregates for different metals and polyethylene plastics to get the absolute best results.

For some small companies with one blasting cab, they tend to use a one slurry mix for all projects, so while you can still get ok to decent results, that's not the best way to do it. Choose a company that has several cabinets set up for both PE and alloys or one that will change the slurry to accommodate PE.

Some may argue that they can adjust pressure and distance to get the desired effect, so while that might be true in some cases, I want those who are willing to go the extra mile and that cares about my 40 year old parts enough to do it the right way. Anyway, I believe if I am not mistaken, the slurry mix that was used on my box was granulated walnut with around 55psi nozzle pressure. I will look for my old receipt and see if I can get you the contact number for these guys as this was done about a year and half ago.

OMG!!! That was you??? I remember reading about that. I believe you had a thread or mentioned it a few times on other 4V2 threads here at Vital. WOW!!! Unreal. I can only imagine the pain and suffering over that ordeal. Sorry to hear that was you my man, but it's great to see you are still doing and enjoying restorations. I love this 79 Elsinore rebuild. Have you checked out Hulk's CR500 thread from France?? INSANE!!!

Not sure if your up for making new friends from the internet after having a bike ripped off, but if you ever want to BS over these rebuilds and maybe let me pick you brain over the YZ, we can exchange emails or numbers or something, I might be able to learn something I haven't thought of...

Have a good one and keep up the pics, I love staring at these childhood friends of mine... LOL!!!



The last pic I took of my yz before it got stolen. That was about 11 years ago. Being my first build I made the mistake of using too many NOS parts. Drove price up too much. Live and learn. Thanks for the vapor blasting info.
The other picture is my current condition resto/racer. 1974 Husky 250 Mag. Been waiting on engine for 10 weeks now (needs sleeve & machine shop backed up). Hope to be done within next couple months.

I have not seen Hulk's CR500. I'll check it out. Feel free to shoot me an email if you have any questions (my screen name at yahoo dot com).
9/7/2021 3:37pm
mxchris208 wrote:
I didn't know that. Thanks for the tip. I'm assuming set at low psi? I do ride/race all the bikes I build bikes. It hurts to...
I didn't know that. Thanks for the tip. I'm assuming set at low psi?
I do ride/race all the bikes I build bikes. It hurts to see them get scuffed or scratched up but I guess I just enjoy riding them more.
Years ago, my very first resto was a '81 yz125. That was a fun project. Unfortunately as soon as I finished it, it was stolen. Never even got a chance to ride it.
A good reputable medium blasting facility will use different slurry recipes for different materials. While anyone can use wet silica on anything and everything, the results...
A good reputable medium blasting facility will use different slurry recipes for different materials. While anyone can use wet silica on anything and everything, the results aren't as good as those company's who know how to mix different aggregates for different metals and polyethylene plastics to get the absolute best results.

For some small companies with one blasting cab, they tend to use a one slurry mix for all projects, so while you can still get ok to decent results, that's not the best way to do it. Choose a company that has several cabinets set up for both PE and alloys or one that will change the slurry to accommodate PE.

Some may argue that they can adjust pressure and distance to get the desired effect, so while that might be true in some cases, I want those who are willing to go the extra mile and that cares about my 40 year old parts enough to do it the right way. Anyway, I believe if I am not mistaken, the slurry mix that was used on my box was granulated walnut with around 55psi nozzle pressure. I will look for my old receipt and see if I can get you the contact number for these guys as this was done about a year and half ago.

OMG!!! That was you??? I remember reading about that. I believe you had a thread or mentioned it a few times on other 4V2 threads here at Vital. WOW!!! Unreal. I can only imagine the pain and suffering over that ordeal. Sorry to hear that was you my man, but it's great to see you are still doing and enjoying restorations. I love this 79 Elsinore rebuild. Have you checked out Hulk's CR500 thread from France?? INSANE!!!

Not sure if your up for making new friends from the internet after having a bike ripped off, but if you ever want to BS over these rebuilds and maybe let me pick you brain over the YZ, we can exchange emails or numbers or something, I might be able to learn something I haven't thought of...

Have a good one and keep up the pics, I love staring at these childhood friends of mine... LOL!!!
mxchris208 wrote:
[img]https://p.vitalmx.com/photos/forums/2021/09/07/508925/s1200_81_yz125.jpg[/img] [img]https://p.vitalmx.com/photos/forums/2021/09/07/508926/s1200_228607280_272848151313696_1141683257424736574_n.jpg[/img] The last pic I took of my yz before it got stolen. That was about 11 years ago. Being my first build I made...



The last pic I took of my yz before it got stolen. That was about 11 years ago. Being my first build I made the mistake of using too many NOS parts. Drove price up too much. Live and learn. Thanks for the vapor blasting info.
The other picture is my current condition resto/racer. 1974 Husky 250 Mag. Been waiting on engine for 10 weeks now (needs sleeve & machine shop backed up). Hope to be done within next couple months.

I have not seen Hulk's CR500. I'll check it out. Feel free to shoot me an email if you have any questions (my screen name at yahoo dot com).
So true, I am willfully making that same mistake, been collecting nos parts for years now. The roller I have was running when I bought it, but the top end spit out out a circlip and ruined the bore, head and did some additional damage to the bottom end. The seller boasted it just had a new top end put in it at time of purchase, but I suspect they did not use brand new piston pin circlips and that's a huge no-go. I should have known better as I usually tear into the motor before riding pre owned bikes no matter what people say they just had done. I barely got an hour out it and poof...

That husky looks like another fantastic project. We had an ole 360 viking, I can't remember the year, but I think it was a pre-owned 68 model we purchased in the late 70's. I used to ride that thing when I was 10 years old and could not get enough of that 4 speed torque. We had problems with the woodruff key shearing off the crank several times over the course of a year, but when it ran it was a beast...

Wow, awesome looking YZ!! Are you going to stick with the standard exhaust routing and configuration on the mag? I've seen some custom wrap around cross over exhaust systems on those...

What type of riding are you doing with the 79 Elsinore? I have to haul my bikes a couple hours away just to ride on private property...

CR500 thread: https://www.vitalmx.com/forums/Bike-Builds,46/Two-Stroke-project-2019,1…
mxchris208
Posts
19
Joined
12/6/2018
Location
Sanford, FL US
9/8/2021 12:06pm
A good reputable medium blasting facility will use different slurry recipes for different materials. While anyone can use wet silica on anything and everything, the results...
A good reputable medium blasting facility will use different slurry recipes for different materials. While anyone can use wet silica on anything and everything, the results aren't as good as those company's who know how to mix different aggregates for different metals and polyethylene plastics to get the absolute best results.

For some small companies with one blasting cab, they tend to use a one slurry mix for all projects, so while you can still get ok to decent results, that's not the best way to do it. Choose a company that has several cabinets set up for both PE and alloys or one that will change the slurry to accommodate PE.

Some may argue that they can adjust pressure and distance to get the desired effect, so while that might be true in some cases, I want those who are willing to go the extra mile and that cares about my 40 year old parts enough to do it the right way. Anyway, I believe if I am not mistaken, the slurry mix that was used on my box was granulated walnut with around 55psi nozzle pressure. I will look for my old receipt and see if I can get you the contact number for these guys as this was done about a year and half ago.

OMG!!! That was you??? I remember reading about that. I believe you had a thread or mentioned it a few times on other 4V2 threads here at Vital. WOW!!! Unreal. I can only imagine the pain and suffering over that ordeal. Sorry to hear that was you my man, but it's great to see you are still doing and enjoying restorations. I love this 79 Elsinore rebuild. Have you checked out Hulk's CR500 thread from France?? INSANE!!!

Not sure if your up for making new friends from the internet after having a bike ripped off, but if you ever want to BS over these rebuilds and maybe let me pick you brain over the YZ, we can exchange emails or numbers or something, I might be able to learn something I haven't thought of...

Have a good one and keep up the pics, I love staring at these childhood friends of mine... LOL!!!
mxchris208 wrote:
[img]https://p.vitalmx.com/photos/forums/2021/09/07/508925/s1200_81_yz125.jpg[/img] [img]https://p.vitalmx.com/photos/forums/2021/09/07/508926/s1200_228607280_272848151313696_1141683257424736574_n.jpg[/img] The last pic I took of my yz before it got stolen. That was about 11 years ago. Being my first build I made...



The last pic I took of my yz before it got stolen. That was about 11 years ago. Being my first build I made the mistake of using too many NOS parts. Drove price up too much. Live and learn. Thanks for the vapor blasting info.
The other picture is my current condition resto/racer. 1974 Husky 250 Mag. Been waiting on engine for 10 weeks now (needs sleeve & machine shop backed up). Hope to be done within next couple months.

I have not seen Hulk's CR500. I'll check it out. Feel free to shoot me an email if you have any questions (my screen name at yahoo dot com).
So true, I am willfully making that same mistake, been collecting nos parts for years now. The roller I have was running when I bought it...
So true, I am willfully making that same mistake, been collecting nos parts for years now. The roller I have was running when I bought it, but the top end spit out out a circlip and ruined the bore, head and did some additional damage to the bottom end. The seller boasted it just had a new top end put in it at time of purchase, but I suspect they did not use brand new piston pin circlips and that's a huge no-go. I should have known better as I usually tear into the motor before riding pre owned bikes no matter what people say they just had done. I barely got an hour out it and poof...

That husky looks like another fantastic project. We had an ole 360 viking, I can't remember the year, but I think it was a pre-owned 68 model we purchased in the late 70's. I used to ride that thing when I was 10 years old and could not get enough of that 4 speed torque. We had problems with the woodruff key shearing off the crank several times over the course of a year, but when it ran it was a beast...

Wow, awesome looking YZ!! Are you going to stick with the standard exhaust routing and configuration on the mag? I've seen some custom wrap around cross over exhaust systems on those...

What type of riding are you doing with the 79 Elsinore? I have to haul my bikes a couple hours away just to ride on private property...

CR500 thread: https://www.vitalmx.com/forums/Bike-Builds,46/Two-Stroke-project-2019,1…

I'm racing vintage motocross with my bikes. Here's a pic of the '79 at Daytona VSX

I went with the PFR exhaust for the Mag. It crosses over the cylinder head and exits the opposite side than stock. It's also short in length compared to the stock exhaust. I'm hoping to hit a vintage race at GPF in Georgia in October but since I still haven't even gotten my motor back yet, that's looking slim.

Yeah, I've learned that if you don't know the seller then believe nothing. He may be telling the truth but it's not worth finding out the hard way if he's not. I almost didn't take the Mag engine apart because I knew the seller but since he told me that he never had it open whole time he had it I figured I better check. Good thing because it wouldn't have lasted but a moto or two.
3

Post a reply to: 1979 Honda CR125 racer build (lots of pics)

The Latest