Allens Performance Ltd.

CR 29 Smoothbores, Kawasaki Z1000

March 7th, 2018

Just finished! One lucky lad will be able to replace those nasty CV’s with a set of beautiful Keihin smoothbore CR29’s. Complete with specailly made airbox adaptors by Allens.CRS29 Z1000 Carbs carburettors with special Airbox Adaptors


TM24 Flatslide Plus Solenoid Controlled Powerjet

May 25th, 2017

Some powerjet conversions are more work than others… The TM24 really isn’t designed to be used this way. But nevermind, we have a milling machine and we can be stubborn at Allens Performance!

Mikuni Tm24-9 with electronic solenoid powerjet conversion

April 19th, 2017

Here we go!

Replica Yamaha Race Kit Exhaust Flange Castings ready to be machined at Allens Performance.

Many possible applications include RD350LC2 YPVS, TZR250 RD500, RD350LC.


Replica Yamaha Race Kit Exhaust Flange Castings RD350YPVS TZR250 RD500 RD350LC

Yamaha XT225 Serrow Electric Start TM28 Carburettor Conversion Kit

February 8th, 2017

A TM28 carb conversion we developed at Allens Performance to replace the troublesome CV carburettors found on the Yamama XT225 Serrows. This one is for the later bikes with electric start only. It fits the standard rubbers and is supplied with a new throttle and cable kit. Jetted to suit a standard bike. These bikes are a great compromise between light weight for ease of off road use, sufficient performance to be safe in modern traffic and flexible engine performance allowing easy riding on and off road.

Yamaha XT225 Serrow Electric Start TM28 Carburettor Conversion Kit

Yamaha XT225 Serrow Electric Start TM28 Carburettor Conversion Kit

Friday Fun, Poo Infested Carbs

February 3rd, 2017

We’ve all heard that turn of phrase… There’s you know what in your carburettors!

Well imagine our surprise when a customer asked us to sort these carbs out for them. The bike was caught in a flood and effluent flowed in and around the bike! Don’t we get all the best jobs?

Needless to say, they are all mended now..


TMR Carb Service/cleaning sewerage pooh shit TMR Carb Service sewerage pooh shit effluent cleaning

Yamaha SZR660/XTZ660 TM/RS34/38mm Carburettors

February 2nd, 2017

Although the five valve Yamaha engine is a great power unit with many applications, the standard carbs can give rise to serious limitations on a modified machine. Getting aftermarket carbs has been a problem in the past because of the different bore size of each carb. This kit resolves that issue.

The photo below shows a pari of carbs spaced at 120mm. Obviously on the SZR/XTZ set, spacing is much tighter.

Dual Mikuni TM/RS carburettors 120mm pitch XS650 Z750

One 34 and one 38mm carburettor in one rack of two
Adaptor fitted to enable the use of standard inlet rubbers
Carbs will not fit standard airbox


Please ask us for details and pricing or phone 01949 836733.





26J Yamaha Mikuni TZ Reverse Slide Replica Carburettors Built to Order

January 26th, 2017

Fantastic! Finally it’s possible to get a close match for the reverse slide carburettors most sought after by TZ riders rather than put up with tired old orignals. Genuine Mikuni VM carbs modified and set up to suit.

We can also supply slides only if you prefer, or even carbs fitted with conventional brass slides.

Plenty of other TZ carb parts available, just ask for more details…
Mikuni VM38 26J Reverse Slide Replica Carbs Built by Allens Performance Ltd

Manx Norton 500cc Keihin CRS39 Carb Kit. Built to order

January 23rd, 2017

Another specially built carb. Necessary because of the supply situation with Keihin Single CR carbs. This carb includes a sigot to suit a MkII style rubber and the clip on velocity stack with cover.

Single CRS39 Keihin Smoothbore 39mm for Manx Norton 500cc racebike

Classic Mini HSR42 (TM42-6) Flat Slide Carb Conversion

October 6th, 2016

Our Carburettors don’t just end up on bikes, here’s a cracking little mini, much fettled and fitted with one of our Mikuni flat slide carbs! Apparently you can’t go far in this without getting the thumbs up. Shown here just after the a quick bit of setup. (As a slide type carb they are nice and simple to set.) According to our customer it has transformed the car!



Jimmy Doom Special Doomster Engine

September 4th, 2016

Feast your eyes on the Mammoth Vee Twin of Doom!

Here you can see a prototype for a run of extra special engines conceived and developed by the most eccentric Cylinder Head guru in the North, Jimmy Doom.

The bore/stroke of 4.250″ x 4.250″ gives a total capacity of 120 cu in (around 2 litres.) 2.100″ valves are fed by VM44 carbs supplied by Allens Performance Ltd. Cam lift is 0.650″ and the exhaust headers are a full 2″ diameter.

Doomsters are destined for a new wave of muscle bike so watch this space!


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