Yamaha TZR 125 tuning

[thuganomics16]

hi every1 desperatly trying to hit the 125mph mark on my yamaha tzr 125 without ceasing the engine, any recomended tuning parts that wont break the bank?? any help would be appreciated cheers lads and lasses

[mchaggis]

A differently geared speedo drive. It's the only way.
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[simon1221]

Youve got no chance of getting to 125mph on a tzr125, standard derestricted is 20bhp which is about 90mph if your lucky.

To get it to 125mph or closest, you would have to upgrade absolutely everything to aftermarket or tuned parts and probably a big bore kit as well. This will absolutely decrease engine life to about an hour i think , and will cost you more than a decent 250/400 (33bhp) bike that will do closer anyway
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DNA50 (sorry) ->> TZR125l >> GPZ500S

[G]

A standard rs250 should just about hit that; making a tad under 60hp.

Even GP 125 bikes that are rebuilt every race don't make that much power.

[tatters]

l,ve got some racing circlips and a power band if you are intrested
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[Kickstart]

Hi

Not really a hope of getting it to do that. A full power one might have claimed around 27hp, but realistically they were around 21~22hp and would top out at around 94mph (true top speed, the speedo is not that accurate).

Performance Bikes had a 125 frenzy years ago when the TZR was fairly new. There was one there which was quite highly tuned and it did just about manage to scrape to (from memory) 102mph.

A TZR250 would not manage 125mph as standard, although it would just about scrape to it with the gearing raised a touch.

All the best

Keith
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[MarJay]

125 is the engine capacity, not the top speed.

Oh, my Triumph Daytona 955i does 955 miles an hour!
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Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[ts50x0]

go and ask the aprilia 125 GP team coz their 125's will probably just do that. with a lot of money spent then you could probably get the speedo to read 125 but it will be about 110mph really and that would be cheating.

[dodsi]

Can I recomend an act of god?

Because thats what it will take.

[stevo as b4]

What about a tuned XT600 engine? if that will fit into your TZR without shaking the bike to bits, you may get closer to 125, but really to guarentee it, i would stuff nothing less than a 500cc MX engine into your bike. Then if you can gear it high enough on available sprockets, you should get 125mph.

[RS1Banger]

if you really need a 125 to go that fast, get a honda rs125 and put lights on it, etc.
They've been repeatedly clocked at over 130mph

[DM]

I've heard many a time of 125 GP bikes reaching, and in some cases, surpassing 130 mph.

[dandit]

one word .... NITROUS
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WHAT DO YOU MEAN 100 MPH THATS IMPOSSIBLE I STILL HAD 3 GEARS TO GO OFFICER. Currently riding a naked cbr 600 and driving a 52 plate 2litre tdci mondeo

[MarJay]

[simon1221]

Dont you be dissing 1991 TZR's , they may be clapped out but still cheaper than others.
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DNA50 (sorry) ->> TZR125l >> GPZ500S

[nigel]

lose weight .lower bike.

[thuganomics16]

oh my TZR is toatlly standard except the exhaust system and bored out engine and the spedo reads around 118 mayb its over reading then

[thuganomics16]

and where did you lot get 20bhp from?? i think 27-28 is a bit closer

[Kickstart]

Hi

27~28 might be what Yamaha claimed, but the reality will be around 20.

Yes your speedo will be over reading by a massive amount. Think the old RD125LC wth the same clocks would indicate those kind of speeds while barely managing 100mpg in a seriously highly tuned condition.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[stevo as b4]

Yeah the 25-26bhp that yamaha claim is at the crankshaft of a full power variant. The rear wheel measured figure is likely to be nearer 20bhp. Ive seen DT125 dyno charts showing full power bikes making 18-20bhp at the wheel (using std exhaust). The TZR might possibly be 1-2bhp more at the most as i belive its tuned slightly differently for less low down power and better top end. If your TZR makes 21/22bhp at the wheel then your doing really well! I belive yamaha claimed 28bhp from the later Jap built TZR125R's but ive never seen one dyno'ed. forgeting the 125mph fantasies, ive heard of 170cc big bore kits for the DT/TZR, so you could try that option if you want to go a bit faster.

[TzrLover]

old thread now but feel i should add to it i have a 1994 tzr125 import tht has a proved 33bhp at the bk wheel and a gsxer 600 clocking it at 117mph an ur welcome to test it so this thread is full of bollox

[MarJay]

[Kickstart]

Hi

More proof of how inaccurate a stock speedo is. Original TZR250 needed a real 45hp to make 120mph.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[veeeffarr]

[dandit]

on the note of speedos i allways thought my bmw 7 series had a reliable speedo being german and all but i hit 140 on bmw clock and gps only showed 136 so allthough its not far out it was still out my old bandit used to show 135 but was only doing gps speed of 126
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WHAT DO YOU MEAN 100 MPH THATS IMPOSSIBLE I STILL HAD 3 GEARS TO GO OFFICER. Currently riding a naked cbr 600 and driving a 52 plate 2litre tdci mondeo