Honda MR50 works minibike

Related:
Create New Tag

7/29/2018 7:14 AM
Edited Date/Time: 7/29/2018 7:15 AM

Hi all ! With the 2001 Ricky Carmichael MXdN build being done it's time to move to another build !

Photo

Some months ago i came across the internet a picture of a mini vintage dirtbike that immediately pulled my attention !

Photo

After some research i found out this little bike was a Honda MR50 built and customized by Terry H.
It was at that moment i decided to do something similiar with a MR50, make it look like vintage works bike !

After some more research i found out that MR50's only were available from 1974-75 in USA, Canada and Australia ! So here in Belgium/Europe these little MR50's are very rare.
I found one for sale in the U.K. across the channel, all original and 95% complete, i immediately bought it and picked it up. I know it's not perfect condition but still it's all original.

Photo

Then some weeks later i found another one for sale in The Netherlands, totaly f*cked and screwed up ! Missing alot of the major parts… At that moment i decided to buy that one too and use that one for the project.

Photo
Photo
Photo
Photo

To be honest, the first MR50 i bought was too nice and too original to rebuild it into something completely not original ! So it's stored away in my mancave for now and will probably restore it back to showroom condition in some years.
Enough talking and let's get to the actual project !

Everything stripped.

Photo

Started with restoring the forks. Cleaned and degreased all the internal parts and lower fork legs.

Photo
Photo

Then glassbead blasted the old paint off the lower legs and repainted them in a dark grey color.
Pair of fork gators, fresh oil and new seals and they perform like new. Luckily there was no rust underneath the chroming at the pieces that slide through the seals. Rechroming takes up to a year in Belgium so that is something to be done later on !

Photo

The seat and pan were in pretty poor condition ! The metal seat pan had some rust on it, after sandblasting i repainted the seat pan in black and got a new seat cover off Ebay. Used a fuel line as protection for the seat pan edge not to cut through the seat cover.

Photo
Photo

I kind of screwed up the chassis from this bike when trying modifying it, so had to buy another frame on Ebay ! Everything went well the 2nd attempt, the extra tubes are meant to make the bike look like the big bikes with a full frame. Still need to weld eveything together.

Photo

Received my parcel from RE-MX.COM with all of the major restorations parts needed !

Photo

The wheels were in pretty poor condition too. The chroming was just completely shot and the original tires were just rotten away ! Had to cut all the spokes to make the hubs free.

Photo.
Photo

Fresh glassbead blasted hubs and painted black with new bearings and seals in.

Photo

Got new spokes and nippels and the rims were sandblasted to get rid of the rust and chrome, and after that they got a anti rust treatment and powder coated into a gold looking color.

Photo

Knowing how the wheels looked before, i'm one happy kid seeing this result !

Photo

Started stripping the engine.

Photo

The impact screw driver is probably the best 20 bucks ever spent ! Those philips bolts would just stripped out without a impact screw driver.

Photo

Everything stripped. The top end of this bike was a complete disaster ! Can you see the spacer someone made between the cylinder and cases, this wasn't a good sign ! The cylinder wall is rusted and bored out to 40.95 which is basically the 4th and last oversize Honda makes pistons for. Some amateur that previously owned this bike had a wrong piston in there and to make it work they screwed up the cylinder ports, put a spacer underneath the cylinder to raise it and they took material away from the cylinder head to make it sit lower on the cylinder and they also screwed the dome of the cylinder head. All off this to make a piston work that is not made for a MR50 !
So i bought a good used standard size (40.0mm) cylinder and cylinder head of Ebay which is going to save this engine and save me headaches..

Photo
Photo

More is coming up in the next weeks !

|

7/29/2018 8:14 AM

Awesome. 1974 MR50 was my first real bike. Loved that thing. Real spoke wheels, same look as bigger Elsinore, manual clutch and two stroke. Best of luck. I’ll keep an eye out for your posts.

|

7/30/2018 8:22 AM

great stuff, cool bike...

|

8/1/2018 1:07 PM

Great build, can't wait to see the rest.

|

8/3/2018 11:01 AM

Cool build! Keep it up

|

8/4/2018 2:40 AM

Great build. Good photos and detail. Keep it going.

|

8/4/2018 5:18 PM

get that motor vapor blasted - it'll look like new

|

8/4/2018 9:09 PM

This is so cool

|

8/6/2018 4:02 AM

mxBryan wrote:

Hi all ! With the 2001 Ricky Carmichael MXdN build being done it's time to move to another build !

Photo

Some months ago i came across the internet a picture of a mini vintage dirtbike that immediately pulled my attention !

Photo

After some research i found out this little bike was a Honda MR50 built and customized by Terry H.
It was at that moment i decided to do something similiar with a MR50, make it look like vintage works bike !

After some more research i found out that MR50's only were available from 1974-75 in USA, Canada and Australia ! So here in Belgium/Europe these little MR50's are very rare.
I found one for sale in the U.K. across the channel, all original and 95% complete, i immediately bought it and picked it up. I know it's not perfect condition but still it's all original.

Photo

Then some weeks later i found another one for sale in The Netherlands, totaly f*cked and screwed up ! Missing alot of the major parts… At that moment i decided to buy that one too and use that one for the project.

Photo
Photo
Photo
Photo

To be honest, the first MR50 i bought was too nice and too original to rebuild it into something completely not original ! So it's stored away in my mancave for now and will probably restore it back to showroom condition in some years.
Enough talking and let's get to the actual project !

Everything stripped.

Photo

Started with restoring the forks. Cleaned and degreased all the internal parts and lower fork legs.

Photo
Photo

Then glassbead blasted the old paint off the lower legs and repainted them in a dark grey color.
Pair of fork gators, fresh oil and new seals and they perform like new. Luckily there was no rust underneath the chroming at the pieces that slide through the seals. Rechroming takes up to a year in Belgium so that is something to be done later on !

Photo

The seat and pan were in pretty poor condition ! The metal seat pan had some rust on it, after sandblasting i repainted the seat pan in black and got a new seat cover off Ebay. Used a fuel line as protection for the seat pan edge not to cut through the seat cover.

Photo
Photo

I kind of screwed up the chassis from this bike when trying modifying it, so had to buy another frame on Ebay ! Everything went well the 2nd attempt, the extra tubes are meant to make the bike look like the big bikes with a full frame. Still need to weld eveything together.

Photo

Received my parcel from RE-MX.COM with all of the major restorations parts needed !

Photo

The wheels were in pretty poor condition too. The chroming was just completely shot and the original tires were just rotten away ! Had to cut all the spokes to make the hubs free.

Photo.
Photo

Fresh glassbead blasted hubs and painted black with new bearings and seals in.

Photo

Got new spokes and nippels and the rims were sandblasted to get rid of the rust and chrome, and after that they got a anti rust treatment and powder coated into a gold looking color.

Photo

Knowing how the wheels looked before, i'm one happy kid seeing this result !

Photo

Started stripping the engine.

Photo

The impact screw driver is probably the best 20 bucks ever spent ! Those philips bolts would just stripped out without a impact screw driver.

Photo

Everything stripped. The top end of this bike was a complete disaster ! Can you see the spacer someone made between the cylinder and cases, this wasn't a good sign ! The cylinder wall is rusted and bored out to 40.95 which is basically the 4th and last oversize Honda makes pistons for. Some amateur that previously owned this bike had a wrong piston in there and to make it work they screwed up the cylinder ports, put a spacer underneath the cylinder to raise it and they took material away from the cylinder head to make it sit lower on the cylinder and they also screwed the dome of the cylinder head. All off this to make a piston work that is not made for a MR50 !
So i bought a good used standard size (40.0mm) cylinder and cylinder head of Ebay which is going to save this engine and save me headaches..

Photo
Photo

More is coming up in the next weeks !

rechroome takes a year? in holland we get our parts back in 2 weeks.

|

8/6/2018 11:16 AM

Mike mandemakers wrote:

rechroome takes a year? in holland we get our parts back in 2 weeks.

Yeah it does take up to a year at some companies in Belgium, i’m not even going to talk about the shit service at some places. I used to have a chroming company that did good work, but that man is retired now and quit the business. He was already over 70 years old when he was still in business
One of my friends that owns a car restoration garage sends all his chroming parts to Poland. Cheap, but very good quality and only takes a month.
What is the name of company in The Netherlands ?! I might be interested.

|

8/6/2018 11:19 AM

Thanks for the compliments guys, glad y’all like it !
I’ll do my best to entertain you guys.

|

8/6/2018 11:30 AM

swatdoc wrote:

get that motor vapor blasted - it'll look like new

I have a brand new looking cylinder with standard bore on it’s way and a decent cylinder head both from the USA. These parts will be vapor blasted and kept bare aluminum.
The cases will be glass blasted though because they will be painted in heat-proof black afterwards.
I prefer to have a more rough surface to paint on, that’s why it will be regular glass blasted.

At the moment i’m thinking to make my own DIY vapor blast setup.

|

8/6/2018 1:21 PM

Awesome!

|

8/7/2018 8:12 AM

Cool Build, first bike I ever rode was my Dad's 1974 when I was 5. He still has the bike to this day.

|

I'm not an actual kid
Red Bud Vet Fest 2020: https://www.youtube.com/watch?v=3gpxS0KgQFc

District 14
2017 KTM 150

R.I.P. Steel City

8/8/2018 9:10 AM

mxBryan wrote:

Thanks for the compliments guys, glad y’all like it !
I’ll do my best to entertain you guys.

Looking good Brian
Ga zo door

|

8/8/2018 9:49 AM

Awesome.

|

Tomac and/or Anderson for 2020.....

8/13/2018 8:43 AM

LOVE this!!! Keep the updates coming!!

|

Positively, absolutely 110% obsessed with anything MOTO.

8/14/2018 12:24 AM

mxBryan wrote:

Hi all ! With the 2001 Ricky Carmichael MXdN build being done it's time to move to another build !

Photo

Some months ago i came across the internet a picture of a mini vintage dirtbike that immediately pulled my attention !

Photo

After some research i found out this little bike was a Honda MR50 built and customized by Terry H.
It was at that moment i decided to do something similiar with a MR50, make it look like vintage works bike !

After some more research i found out that MR50's only were available from 1974-75 in USA, Canada and Australia ! So here in Belgium/Europe these little MR50's are very rare.
I found one for sale in the U.K. across the channel, all original and 95% complete, i immediately bought it and picked it up. I know it's not perfect condition but still it's all original.

Photo

Then some weeks later i found another one for sale in The Netherlands, totaly f*cked and screwed up ! Missing alot of the major parts… At that moment i decided to buy that one too and use that one for the project.

Photo
Photo
Photo
Photo

To be honest, the first MR50 i bought was too nice and too original to rebuild it into something completely not original ! So it's stored away in my mancave for now and will probably restore it back to showroom condition in some years.
Enough talking and let's get to the actual project !

Everything stripped.

Photo

Started with restoring the forks. Cleaned and degreased all the internal parts and lower fork legs.

Photo
Photo

Then glassbead blasted the old paint off the lower legs and repainted them in a dark grey color.
Pair of fork gators, fresh oil and new seals and they perform like new. Luckily there was no rust underneath the chroming at the pieces that slide through the seals. Rechroming takes up to a year in Belgium so that is something to be done later on !

Photo

The seat and pan were in pretty poor condition ! The metal seat pan had some rust on it, after sandblasting i repainted the seat pan in black and got a new seat cover off Ebay. Used a fuel line as protection for the seat pan edge not to cut through the seat cover.

Photo
Photo

I kind of screwed up the chassis from this bike when trying modifying it, so had to buy another frame on Ebay ! Everything went well the 2nd attempt, the extra tubes are meant to make the bike look like the big bikes with a full frame. Still need to weld eveything together.

Photo

Received my parcel from RE-MX.COM with all of the major restorations parts needed !

Photo

The wheels were in pretty poor condition too. The chroming was just completely shot and the original tires were just rotten away ! Had to cut all the spokes to make the hubs free.

Photo.
Photo

Fresh glassbead blasted hubs and painted black with new bearings and seals in.

Photo

Got new spokes and nippels and the rims were sandblasted to get rid of the rust and chrome, and after that they got a anti rust treatment and powder coated into a gold looking color.

Photo

Knowing how the wheels looked before, i'm one happy kid seeing this result !

Photo

Started stripping the engine.

Photo

The impact screw driver is probably the best 20 bucks ever spent ! Those philips bolts would just stripped out without a impact screw driver.

Photo

Everything stripped. The top end of this bike was a complete disaster ! Can you see the spacer someone made between the cylinder and cases, this wasn't a good sign ! The cylinder wall is rusted and bored out to 40.95 which is basically the 4th and last oversize Honda makes pistons for. Some amateur that previously owned this bike had a wrong piston in there and to make it work they screwed up the cylinder ports, put a spacer underneath the cylinder to raise it and they took material away from the cylinder head to make it sit lower on the cylinder and they also screwed the dome of the cylinder head. All off this to make a piston work that is not made for a MR50 !
So i bought a good used standard size (40.0mm) cylinder and cylinder head of Ebay which is going to save this engine and save me headaches..

Photo
Photo

More is coming up in the next weeks !

Mike mandemakers wrote:

rechroome takes a year? in holland we get our parts back in 2 weeks.

mxBryan wrote:

Yeah it does take up to a year at some companies in Belgium, i’m not even going to talk about the shit service at some places. I used to have a chroming company that did good work, but that man is retired now and quit the business. He was already over 70 years old when he was still in business
One of my friends that owns a car restoration garage sends all his chroming parts to Poland. Cheap, but very good quality and only takes a month.
What is the name of company in The Netherlands ?! I might be interested.

hard chrome or the parts like bumpers etc of a old car is totally different chrome.
go to micron in Tilburg , I think 100 euro for 2 legs.

|

8/18/2018 9:41 AM
Edited Date/Time: 8/18/2018 9:42 AM

Mike mandemakers wrote:

hard chrome or the parts like bumpers etc of a old car is totally different chrome.
go to micron in Tilburg , I think 100 euro for 2 legs.

Thanks, will get in touch with them.
Please, press the "Quote Last Post Only" button next time !

|

8/26/2018 10:37 AM

Time to bring you guys some updates from the past weeks !

Got the cylinder, cylinder head and intake manifold in last week. All bought off Ebay and shipped to my friend (Tokyo_Tiddler). He collected everything and shipped it to me, thanks again Mike if you read this !
The cylinder is really in almost new condition, not a single cooling fin broken, no rust, and no years and years of dirt caked on it ! The bore is still perfectly on 40.00 which is the standard size bore and the cross hatching is there.
Couldn't have bought a better one for sure ! On Ebay, every single cylinder has at least 1 fin broken, rust, bored out and caked with dirt… So pretty happy with the almost perfect cylinder i have cheerful
I was also missing the intake manifold on this bike, so that is also sorted out now.

Photo
Photo

The cylinder was already fairly clean, but decided to throw it into the ultrasonic parts cleaner. Look at the difference. When you think something is clean, the ultrasonic cleaner gets it next level clean. Don't worry, after cleaning, the cylinder got blowed dry and soaked the barrel with WD40 to prevent it from rusting !

Photo

2 days ago a new ignition coil turned up in the mail.

Photo

Moving further with the brake system. This is how it all looked before.

Photo
Photo

Glass bead blasted and prepped to be painted in the same black color as the hubs.

Photo

Along with some other parts that got blasted.
Footpeg pins and chain adjusters got thrown away due to too much corrosion and wear.

Photo

Some cleaned and painted parts. The brake pedal got painted in the same grey color as the lower fork legs and the throttle tube housing got painted black.

Photo
Photo

Got the airbox painted aswell and a new air boot fitted.
One of the challenges was to find a tahitian red color to match the color of the fenders.
And the first and only spray can i bough matched the fender enough to be satisfied, so that saved me alot of time !
(don't mind the old bolts in the airbox, new ones on the way !)

Photo
Photo


The wheel axles, this was one big mess too ! The front axle requires 1 spacer and 2 washers, obviously the spacer wasn't the correct one, the inner diameter is way larger compared to the outer diameter of the axle + the lenght of the spacer wasn't correct to, that's why there are 4 washers on the axle instead of 2 ! The nut on the end isn't original too and a new OEM one is discontinued by honda, but i'll find a NOS OEM crown nut for sure.
The correct washers and wheel spacer are on it's way.
Later on when checking the parts fiches and looking to photos of how new OEM spacers look like, i noticed that the spacer in the front is an original spacer, but meant for the rear axle !

As for the rear axle, this one had 2 home fabricated spacers, but it did have the original crowned nut.

Photo

So like said before one of the rear spacers was at the front, so i was still missing one of the rear spacers. The one missing is discontinued by honda but i found one on Ebay and bought it right away.
The bottom axle is for the swing arm.

Photo
Photo

The engine cases are at the shop right now because the crank bearing on the right side spins freely in the engine case. When i get the engine cases back, they will get glass bead blasted and painted heat proof black. Then i can start reassembling the engine.
The crank is also at the shop because it needs a new rod, pin and needle bearing.

Some parts i'm expecting to get in the mail next week:
- bunch of new OEM parts
- brand new OEM honda standard size piston
- complete carburetor ( i was missing the carburetor, but this morning i finally found a complete one for sale on Ebay)

|

2/7/2019 9:13 AM

Hey all I am restoring my 74' MR50 and I'm in a slight panic. Took it apart and put it back together for cleaning and some new cables and I have extra parts... Can someone please help me?It has been very hard to find info in the web. Thank you! (ive never posted on a forum before so im not sure exactly the best way to communicate)

|

2/7/2019 1:33 PM

Really nice project Bryan!
The renovated parts and accessories are like new. cheerful

|

My Instagram: maxgodcho

2/9/2019 5:27 AM
Edited Date/Time: 2/9/2019 5:27 AM

Kaleb_Ellis wrote:

Hey all I am restoring my 74' MR50 and I'm in a slight panic. Took it apart and put it back together for cleaning and some new cables and I have extra parts... Can someone please help me?It has been very hard to find info in the web. Thank you! (ive never posted on a forum before so im not sure exactly the best way to communicate)

Here is a link to all the parts drawings: https://www.cmsnl.com/honda-mr50-elsinore-1974-k0-usa_model681/partslist/#.XF7Uq1VKiUk Beyond that, I'd recommend getting a service manual.

To the OP: killer build!! more pics and updates please!!!

|

2/17/2019 5:22 AM

Hi all, after a sudden career switch this project got silent a few months due to having no time. But the last few weeks i have picked this project back up and made some progress.

Some months ago i received the OEM parts i ordered at CMS. Rebuilding with new OEM parts was the way i wanted to go. NOS OEM standard size piston, and new OEM crank pin and needle bearing etc..

Photo
Photo
Photo

I also got in the carburetor i was missing. After an ultra sonic clean it came out fairly clean.

Photo

The left one is from my other MR 50, the one on the right is the one i bought on Ebay and will be used on this project. Somehow the ultra sonic cleaner did a better job on the left one.

Photo

The frame got some attention too, the tubes got welded in and i cut some old unnecessary brackets off that were holding the chain slider and chain protecter. I will weld in new tabs on the swingarm for an custom made chain slider and there will be custom tabs welded on the subframe to be able to mount custom made side number plates.

Photo
Photo
Photo

The engine got disassembled completely to check the internals for worn parts. Months ago i brought my cases to a machine shop because the right crank bearing spinned freely in the case, so they bored the cases out and placed a bushing in there. The inner diameter of the bushing is made for OEM bearing size, that way the engine is still at OEM specifications. A bushing was placed on both sides of the crank cases to make sure the left side is on same spec as the right.

The cases got glass bead blasted and washed in the parts washer to prepare it for painting.

Photo

Everything nicely taped off

Photo

Painted heatproof gloss black.

Photo

The paint job turned out great !

Photo
Photo

All the internal parts got ultra sonic cleaned. Pretty pumped to see all the internal parts are still in good shape. Only the top end was pretty screwed on this engine and the crank bearing was rusty, other than that no major problems got found on this 45 year old engine.

Photo.

Fresh rebuild crank, new pin and needle bearing.

Photo

Bottom end assembled, only thing left to do is prepare the clutch cover for painting and assemble all the clutch components.

Photo
Photo

The fuel tank had some rust in it, i got everything removed with some acid. I also ordered a epoxy kit to protect the inside of the gastank for corrosion and protection for the gasoline. I haven't done the epoxy step yet but will be done next week.

Photo
Photo

At the moment the chassis and fuel tank are in the powder coat shop and should be coated by next Friday ! That means i can finally start to assemble the bike and have it look like a bike again.

Stay tuned !

|

2/17/2019 9:43 PM

Love the project! I have a 1975 MR50 that I just broke down, cleaned and put back together. Starts up first kick every time its kept in a warm place. gunna replace the shocks with something a little heavier here soon!

|

5/7/2019 4:07 AM

Updates from the last couple off months !

Got the frame, gas tank, sub frame and swingarm back from powdercoating and started assembling the bike.
I decided to keep the custom made spacers the previous owners made to raise the front as i wanted this bike to be higher compared to a stock honda MR50.

Photo
Photo

Polished and cleaned up the axles as they didn't look too well before..

Photo
Photo

I finally came to bead-blasting and painting the clutch cover so i could finish up the engine.

Photo

OEM standard size piston was installed as the cylinder still was perfectly at standard size bore.
Also found a perfect condition used clutch pull rod on Ebay as mine was bend and rusty.

Photo

Nothing beats the look of a freshly rebuild engine with shiny new philips screws !

Photo
Photo
Photo

I moved the bike into the house and assembled it there, when it's finished it will end up in the man cave inside the house anyways.

Installed the OEM shocks to support the bike while the longer shocks were on it's way. The bike looked like a chopper here due to the front end being lifted.

Photo

The new plastics, seat and gastank installed.

Photo
Photo


Front and rear brakes installed and the airbox.
I went from 260mm OEM shocks to 320mm shocks, 310mm would have been a little more perfect i think for this bike..

Photo
Photo

Rebuild engine installed, couldn't be more happy how this turned out. It really looks close to how it's bigger brothers CR125 & CR250 from the same era looked back in the days.., just a little smaller and way cooler than how a original unmodified MR50 looks.

Photo
Photo

This project came a long way since march 2018, so pretty pumped to see it finished soon. Next to do is figure out a custom made or modified exhaust pipe and the ignition of this engine, hopefully i can get a spark out of it !

|

5/7/2019 6:23 AM

So awesome! Can't wait to see the final bits come together. Great work.

|

5/7/2019 9:16 PM

Wow Bryan! Awesome job so far on this! I hadn't seen this thread until now. That little Mr50 is gonna be sweet!

|

And there goes Jeffro. One of God's own prototypes. A super high-powered mutant of some kind never even considered for mass production. Too weird to live, and too rare to die.

Pimpin' Ho's , Rollin' fatty's......drinkin' beers , beers , beers!! ~ Ja

11/3/2019 2:21 AM

Some updates from the past months !

I finally had all the electrics installed and all the controls like clutch cable, gas cable, brake and clutch lever etc..

Photo
Photo

Got a new spark plug and spar plug cap installed. Was a very happy kid to see all the 45 year old electrics still work fine and delivers a nice spark to the spark plug !

Photo
Photo

This is how the bike sits right now and is finished for 95% i'd say..
I still need to make custom numberplates and make a custom exhaust pipe, other than that i still need to buy a piece of fuel line, a vent hose for the engine, clamps for the carburetor and need to find a way to seal the carburetor as i threw away the old seals that the carburetor had ! A carburetor seal set is discontinued so i will need to find another solution.

Photo

When the bike is completely finished, i'll make sure to deliver some professional photographs of the bike outside !

|