Derestricting a yamaha tzr 50

[cdarnell]

Hi i have just bought a yamaha tzr 50. I am looking to derestrict it so i can keep up with traffic. What can be done.

[TPS]

cdarnell said:

Hi i have just bought a yamaha tzr 50. I am looking to derestrict it so i can keep up with traffic. What can be done.

How old are you.If your 16 you really dont want to be messing around trying to make it go faster than its legal top speed.Sooner or later you run the risk of getting caught by the police and if you were to have an accident do you want to run the risk of having your insurance invalidated.
If your 17 or over just get a 125 as it will be faster and more reliable.

[Rubin215]

If you want a faster bike, buy a faster bike.

Okay, the fastest ever 50cc bike was something ridiculous like a 24 gear Kreidler that did 130 odd mph, but do you honestly think any amount of tuning will get you anywhere near acceptable performance and still stay rideable or reliable?

If you're on L plates, pass your test.
If you're only 16 then wait a bit then pass your test.
Either way, save your money for a proper bike.

However, if you're just an eccentric millionaire with money to burn on a ludicrous pet project then that Kreidler gives you something to aim for...

[r5gttgaz]

Start looking at the Dutch moped racers, they ain't happy unless their TZR 50's are doing 110mph +

They use them for endurance racing and don't increase the capacity.

[Carl-H]

It may well be illegal to derestrict a 50 but being restricted to 30 is dangerous, even in a 30 limit.

[TPS]

Carl-H said:

It may well be illegal to derestrict a 50 but being restricted to 30 is dangerous, even in a 30 limit.

Its been many years since i had a 50 but even then it did 35 are you only able to get 30 out of them now?

[Alex@POD]

I had a TZR 50 back in the day... The restrictor was taken off and it would do 65 easily... Dunno what was involved though sorry. And for what it's worth, I think at that age a TZR is much better practice than a scooter, good choice!

[catso]

How are they restricted? intake/exhaust/electronics?

It may be illegal but I'm sure many of use 'fiddled' with our 50s to get a bit more from them, when I were a lad a bigger carb and a few exhaust 'mods' were the favourites.

I had a twist n'go 50 in the late '70s that would do an indicated 50 ish after a few 'tweaks' surely a geared bike could do a little more.

[Carl-H]

TPS said:

Carl-H said:

It may well be illegal to derestrict a 50 but being restricted to 30 is dangerous, even in a 30 limit.

Its been many years since i had a 50 but even then it did 35 are you only able to get 30 out of them now?

They are restricted to 30 but once derestricted most will do 45+.

[m3psm]

I don't know the TZR50, but many 50's are restricted by a washer in the exhaust where it fixes to the engine. Take off the ehaust, remove the washer, refit the exhaust (with a new exhaust gasket) and Bob's your mother's brother

After that it's carb jetting/size, inlets and electronics which get pricier.

As mentioned above, 30mph is lethal but more is illegal so be careful. I'f you ride a derestricted bike you could easilly be deemed to have no insurance or licence, not that it stopped many us when we rode them

Edited by m3psm on Tuesday 19th February 08:50

[kingb]

in my opinion is more dangerous to have a 50cc bike restricted to 30

it ment i could get 15 mph tops when i was going up hill which ment i held up the traffic which pissed people off and made the overtake stupidly

when i derestricted mine which was simple by removing a washer in the exhast - 2 minutes jobs it would go all the way to 60 but more importantly would do 30-35 up hills

however i did s**t myself when i was stopped by the police - i was doing 40 in a 60 - but they just said most young guys riding bikes like this have no form of licence so as soon as they had seen mine they sent me on my way

[Fire99]

Well i had a little search with Google and it does look like the TZR is (or was) the fastest of the 50cc brigade.
Firstly it looks like there is a restrictor washer in the exhaust (at the header/downpipe end) which needs to be removed.. or you could buy an arrow race pipe and keep the original for when you sell the bike on.
However you will probably need to fit a larger jet in the carb to keep the fuelling right.
All pretty easy stuff with a bit of know-how.

Thats a good start.. should see about 50-50mph..i've not read anything about them being electronically governed or anything..

Not gonna get into the legal aspect as i still remember how i was back when i was 16 and at the end of the day you pays your money and takes your choice..

rgds,

Nick

[cdarnell]

I am 16. The derestriction is there so the speed and acceleration is there when i need it, such as pulling out of a junction on a bypass

[cdarnell]

I think that there is a elecctronic limiter on it as well some where.

[catso]

cdarnell said:

I am 16. The derestriction is there so the speed and acceleration is there when i need it, such as pulling out of a junction on a bypass

Change the gearing (larger rear sprocket) to get more acceleration, although this will cost some mph at the top (which could be got back by removing said exhaust washer etc) this would also help to maintain a better speed uphill.

That's what I've done to my bike.

although I had no problem exceeding 30mph before...

[cdarnell]

I will have to have a look. I haven't got the bike yet. I am picking it up on saturday.

I think i will try and stay to the cheap and simple modifications.

Then i will most proberly sell it a year on and get a bigger bike. Or get a car

[Carl-H]

Don't bother changing the gearing loads. You will just end up with something that needs to change gear every few feet and is redlining in top at 40

[cdarnell]

I think im just going to take the metal washer out of the exhaust and leave it at there. Then i will just tart it up by chroming the kick plates

[black-k1]

cdarnell said:

I am 16.

De-restricting the bike will stop it being classified as a moped which means you are not licensed to ride it which means insurance becomes questionable to say the least.

While I agree that only being able to do 30mph is a pain, make sure you fully understand all the implications and possible consequences of what you are considering doing!

[cdarnell]

When i was looking around for a 50cc. I had three types of bike makes i was looking at, an aprilia rs 50 a derbi gpr 50 or this yamaha tzr 50.

I was told that the yamaha tzr was the most bullet proof out of the three.