Author Topic: YR5 racing bike  (Read 796 times)

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Offline korneel

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YR5 racing bike
« on: August 03, 2018, 01:34:40 PM »
hello ,


I bought this winter an Yamaha YR5. I bought it at around 15km from the legendary track of Spa-Francrochamps, owner had build it in the late 70's as everybody from around could race there during the wekends.

Bike is in fearly condition , engine is good , owner couldnt remember where the expansion pipe's where. he had them up the bike in the 70's but couldnt remember what he had done with it .....

https://imagizer.imageshack.com/v2/800x600q90/922/Yb8I7V.jpg

For now i only have this picture off the bike
there where some parts with it but not a lot... ( headlight , tacho , and some brackets .... )

What i could like to do with this bike :

-restore the polyester bodykit eventhough it's not even a TD3 replica
(eventualy i would like to rebuild them in aluminium)
-refurbish the brake's
-new tyre's ( any recomandations on affortyble track tire's ??)
-rebuild engine ( would love to put a 6 gear box in there )
-new pistons
-electronic ignition
-carburators ( anybody with good advice on that ? I'm thinking at mikuni TM's 32-34 ?
-mild porting of the engine
-expansion pipe's ( i allready have those )
https://imagizer.imageshack.com/v2/800x600q90/921/C4HNOx.jpg
https://imagizer.imageshack.com/v2/800x600q90/923/bo31uJ.jpg
-polyester TD3 fairing
-hagon shocks in the back
-rebuild front fork

That is what's now in my head for this bike , i'm new to the circuit part of motorcycling so please ... If you have thoughts , tips , parts , let me know :-)
I dont have the biggest budget so please keep that in mind :D


thanks anyway !

« Last Edit: August 03, 2018, 01:56:00 PM by korneel »
-RD 125 DX 1977 cafe racer
-RD 250 C 1976 daily bitch
-YR5 350 1972 track bike

Offline kawazonkey

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Re: YR5 racing bike
« Reply #1 on: August 03, 2018, 10:12:04 PM »
I like that!

Tyres...not sure on track day specific tyres (and no idea if there are any for 18" rims)  but a very good tyre is Bridgestone BT45's. I swear by 'em.

Offline 5port

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Re: YR5 racing bike
« Reply #2 on: August 06, 2018, 11:17:43 AM »
You don't say what you are trying to do.  :-\
Is this a restoration, for road legal, for track only?  Please explain.  Thanks

5port 
5port

Offline korneel

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Re: YR5 racing bike
« Reply #3 on: August 07, 2018, 06:30:00 AM »
You don't say what you are trying to do.  :-\
Is this a restoration, for road legal, for track only?  Please explain.  Thanks

5port

Basically it wil be a track bike , i'm waiting for a response from yamaha. Normally i should have the correct paperwork for it , i'm considering to just put some smal lights on it so it can be road legal. But on the other hand then i cant place a HPI race ignition .....

Best chance it will be a track bike , and keep the papers for future projects ... :)
-RD 125 DX 1977 cafe racer
-RD 250 C 1976 daily bitch
-YR5 350 1972 track bike

Offline 5port

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Re: YR5 racing bike
« Reply #4 on: August 07, 2018, 09:22:48 AM »
OK, but your budget will be considerable to do a good job.  ???
Tyres for track day, BT45. (£200)  If full race, AVON race AM22/23 (talk to racers £300).   Tune, fresh crank, carb conversion, RD400 transmission conversion (£1000).  Powerdynamo race ignition (£400).  Wheel rebuilds. (£400)  Also, you might find a good result with a change to RD350 cylinders and reed valves.  This gives a maybe slightly more flexible engine and, a wide choice of pistons.
Cheers

5port
5port

Offline betty foRD

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Re: YR5 racing bike
« Reply #5 on: August 07, 2018, 05:07:58 PM »
My advice is to think how else you could spend €2.5K in the quest for a tidy track bike and then think again about the best future for this non standard R5 barn find ....

Most of us have followed our credit cards into the ‘deep chasm of regret’ at one time or another....
Rev 'em till they rattle

Offline 5port

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Re: YR5 racing bike
« Reply #6 on: August 07, 2018, 10:35:04 PM »
Yes, you could try making it work with all its original parts that you have.  The motor might be quite good?  :)

5port
5port

Offline korneel

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Re: YR5 racing bike
« Reply #7 on: August 08, 2018, 08:51:31 AM »
OK, but your budget will be considerable to do a good job.  ???
Tyres for track day, BT45. (£200)  If full race, AVON race AM22/23 (talk to racers £300).   Tune, fresh crank, carb conversion, RD400 transmission conversion (£1000).  Powerdynamo race ignition (£400).  Wheel rebuilds. (£400)  Also, you might find a good result with a change to RD350 cylinders and reed valves.  This gives a maybe slightly more flexible engine and, a wide choice of pistons.
Cheers

5port

I know ... i have giving it a lot of thoughts allready .... i'm no gonna swap cilinders to reeds becouse in belgian compitition its forbiden to have reed valve's for classic races , i would wanna change the heads with RD one's because the R5's crack .... i havent stardet on buying parts for it so i'm still thinking about it. It has crossed my mind to buy an RD250/350 race ready for 2.5-3k and that would be the best deal , but so for nothing came up....

if i do the maths i know it gonna cost quite some money

-fairing (200)
-ignition (250)
-tires (250)
-engine tune and rebuild with parts (heads , pistons, gearbox,seals,bearings) (1000)
-carbs (300)
-exhausts have cost me allready 350 i think

wouldnt wanna change to mutch on the wheels , there good. Just rebuild the brake's and ventilate them .

(prices in euro)

In mind that i havent payed a lot for the bike , i'm still wondering if its all worth it ..;
-RD 125 DX 1977 cafe racer
-RD 250 C 1976 daily bitch
-YR5 350 1972 track bike

Offline stukey

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Re: YR5 racing bike
« Reply #8 on: August 08, 2018, 09:43:41 AM »
You can build a race-bike on a budget depending on wether you want to race for fun or be in the top ten.If you want to be in the top ten, you will need to spend a lot of money and also be a very good rider. R5's are easy to tune and other race people will help you out . You can buy second-hand bodywork and do a lot of the work yourself.If the crank is servicable,use it for now you will have to rebuild it at the end of the season anyway.Same with barrels. You might lose a few bhp by running tired bores but it will not diminish the fun.You do not need a 400 gearbox at a £1000 there are other ways ;) ;).Get it together and get out there.You will get loads of help in the paddock and will pick up bits from other racers. Rather than overpriced evilbay :o
Rd 350 special can we get more than 70bnp?
Silver-dust 350b now with new owner
Barnfull of shitty shit
and not forgetting the r6 streefighter
 R1Z 250

Offline korneel

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Re: YR5 racing bike
« Reply #9 on: August 08, 2018, 10:19:39 AM »
You can build a race-bike on a budget depending on wether you want to race for fun or be in the top ten.If you want to be in the top ten, you will need to spend a lot of money and also be a very good rider. R5's are easy to tune and other race people will help you out . You can buy second-hand bodywork and do a lot of the work yourself.If the crank is servicable,use it for now you will have to rebuild it at the end of the season anyway.Same with barrels. You might lose a few bhp by running tired bores but it will not diminish the fun.You do not need a 400 gearbox at a £1000 there are other ways ;) ;).Get it together and get out there.You will get loads of help in the paddock and will pick up bits from other racers. Rather than overpriced evilbay :o



It is definitely the pourpose to race on an budget and to have fun , and not to be at the top. I think you can find 350RD gearboxes for 200euro in france if you search wel ... If i could find : carbs and ignition and mayby some good tires ( i'm planning on driving the track 3-4 time's next year) second hand , that would really really help my budget ....
You guys don't have a for sale area at the Forum i see ... Any advice , or people i should contact ?
-RD 125 DX 1977 cafe racer
-RD 250 C 1976 daily bitch
-YR5 350 1972 track bike

Offline betty foRD

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Re: YR5 racing bike
« Reply #10 on: August 08, 2018, 01:42:56 PM »
You need to be a club member then you can access other parts of the forum with for sale, wanted, members stuff etc.

Price is very reasonable and includes a magazine each quarter or thereabouts.
Rev 'em till they rattle

Offline korneel

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Re: YR5 racing bike
« Reply #11 on: August 08, 2018, 01:56:20 PM »
You need to be a club member then you can access other parts of the forum with for sale, wanted, members stuff etc.

Price is very reasonable and includes a magazine each quarter or thereabouts.


allright !! will look into that tonight !
-RD 125 DX 1977 cafe racer
-RD 250 C 1976 daily bitch
-YR5 350 1972 track bike

Offline 5port

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Re: YR5 racing bike
« Reply #12 on: August 10, 2018, 09:06:58 AM »
It will cost you, unless people give you the stuff. :D   Have you got a better picture of the bike because in the one you posted the wheels don't look good.  :-\   As for the Gbox, you have many options but, you need to know what they are so you don't waste £££. ;)  Very generally, the early RD250/350 European bikes have the 6-speed with wider ratios and 6th blocked by the pawl plate on the selector.  You can change this to use all 6 gears but, it still has the wider ratios.  The 521/522 model bike has the gearbox modified with all 6 gears working and closer ratios. :)  The  RD250/400C  came with the same closer ratios and some further upgrades to some gears and, with different clutch and sprocket splines.  Complete Gboxes can be bought for less than £100 online, or maybe you will get a good one for less? 
As this bike has been used on the track (raced?), it is worth finding out what the engine is like inside and what modifications it has already had.  :)   

5port 
5port