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Discussion Starter · #1 ·
Well I've come across a very nice project. My step dad's mate has recently bought a TZR125 which wasn't working so he brought it down to our garage for us to work on. It wouldn't start and there was next to no compression so we took the head and barrel off, which took ages due to 3 seized bolts that had to be chizeled off. Seeing as the bike has done 41000miles we came to the conclusion that the engine is scrap as the powervalve had been welded up for some reason and the piston is past it. I don't know about the bottom end.

So anyway he's decided to sell it after buying it the other week for ?200! He said he'd be happy with ?100, is this ok? I don't know what year it is, but it has a single peice seat rather than 2 like the newer ones. The guy has all the plastics, 2 sets of wheels, 2 exhuasts and all the documents.

I was going to buy a second hand working engine for it, but I've found TDR/TZR250 engines available for not much more than a 125 engine. Would it be possible to fit a 250 engine without modifying the plastics? Frame mounts won't be too hard as I have a friend who is a welder and i'll be able to fabricate simple mounts at least. But I have noticed it's a very thin bike and I don't want to have to keep the front plastics off it, or have to do major modifying to the frame.

The only problem I can see at the moment is that garage space is at a premium with both my parents owning 2 bikes each, 2 Honda Goldwings (1100 and a 1200), a BMW K1100 and a Monkey Bike, plus my TDM and now this TZR125. All this just about fits in our single garage, but not easily.

Here are a couple of pictures of the bike...



And my full garage!


Mik
 

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Discussion Starter · #3 ·
I'd like to be able to ride it for a good few thousand miles before having to strip it. So a road bike engine is the way i'll go, just don't know which will fit within the plastics. After looking at some TZR250s though they are very thin too so might just fit, but i'll go to my local scrap yard and see what donor bikes i can find there.

Mik
 

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if you have the standard yamaha fairaing(plastic not fibreglass)then you could extend the mounting brackets a little,to give yourself a couple of inches,if you need them.on the other hand,any part of the engine that is too wide,cut a hole in fairing for it,to create a unique look
 

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Discussion Starter · #6 ·
I've not seen the plastics yet, but i'm sure they are originals.

So far I've considered the following engines:
TZR250
TDR250
RD350LC

The way I see it I might as well make it a big convertion if i'm going to do it at all, but then again I might just restore everything so it looks stock, but it'll have 2 pipes. I'll have to have both pipes on the same side of the bike, cos I don't like the look of a pipe on each side... Hides TDM pipes...

Mik
 

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i think the 350 would be a struggle,if you had a tzr125r,i would tell you to go for it,as the package can handle the power,but unfortunately,this model would not suit.you would have to upgrade the brakes,and wheels(for better tyres)and i think by the time youd got that far you would have defeated the object.all respect for your intentions (been there-done that etc...)

the original tzr250 was very simillar(if not the same)chassis if i remember rightly,and would be much easier engine to put in your frame,with simmilar electrics and blah blah blah.

keep in touch and let us all know what you decide to do,and let us know how it goes!
 

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Discussion Starter · #9 ·
why would you need to upgrade the chassis so much for 350 lc power...?

look at 350 lc wheels brakes an sus an tell me their any better than standard teezer ones...
I was gonna say. I've seen a couple of RD350LCs with similar, if not the same, wheels on as my TZR125. I'll be fitting a disk brake to the rear, somehow, but otherwise i want it to look stock, but with a load more power. Sleeper style


Mik
 

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sorry,i thought you meant the 350ypvs,yeah, i suppose you could make this work then,and to be fair,my old man had a track prepped lc,and he used a tzr125 shock.im totaly into the wolf in sheeps clothing thing,and just waiting for the funding to finnish mine.i have a manual for the same tzr as you have,and access to a manual for an rd lc so if you need any help let us know,

oh and the tzr250 has identical looking wheels(as do the fzr) but in slightly larger sizes
 

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Discussion Starter · #12 ·
I am on about the RD350LC with YPVS. To handle the extra power I'll fit a slightly newer swingarm with a disk brake and then might consider USD forks off the newer TZRs. Ideally I'd want it to look as stock as possible tho


Mik
 

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at the end of the day if your wallet is big enough,theres nothing you cant do!or if you have the tools and know-how,but there are alot of bikes out there,that are absolutely fooked,because some one has "had a go"
Its all a case of weighing up the pros and cons.

let us know what you decide to do
 

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Discussion Starter · #15 ·
Well my wallet is pretty small at the moment. I'll do my best not to ruin the frame by welding bits to it, I'll try to just bolt everything in place so it could be turned back if it ever had to be. It's definitely gonna be a long term thing, but I hope to have it all done by summer


Mik
 

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Seeing as the bike has done 41000miles we came to the conclusion that the engine is scrap
*ahem* mines on 41,600. and my engine is fine


but yours looks like the super old model w/ the drum brake. you should be able to shove another engine in it, like the old 250 engine.
 

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The biggest problem will be chain alignment, the 125 is a very narrow bike as you have noticed and the TZR and RD are both parallel twins which are quite wide engines, I am not sure you would be able to offset the engine enough to get the chain alignment correct. The 250 chasis is alot wider, personally I would go with another 125 engine, less work required and it should do at least 15000 miles with too much attention.
 

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Discussion Starter · #19 ·
Seems the bike still isn't mine. My step dad was meant to be sorting it out with the guy, but I think he's going to advertise it first, even though I said I'd give him what he wants for it.

I've had a look at the plastics and they'll need a respray, they're not really bad though. I don't recognise the paint scheme though, it's a Loctite scheme. Don't know if it's a race rep or just a random paint job.

Still hoping to fit a RD350LC engine in it. I'll measure it all up once I know the bike will be mine.

Mik
 

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cr500 sounds good idea, i can see where the chain alingment may be a problem, you;d have to have the other end of the engine sticking right out, or fit a bigger rear swingarm and wheel, which opens up a hole load of new problems

id go for, cr500 engine like gavins, a standard blue TZR paint jobbie, or one of the older yellow and black

try and fit a rear end of one of the TZR-R's or possible the 250, TZR-R front end, with yokes and forks and wheel, (would go well with the R rear end, that way ud have the R brakes too which i think are better than the earlier models, other than that keep it standard, and wipe the smile off the ponsy RS125 riders when they attempt to race you
 
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