Best 2-stroke engine?

**F5 Dave** · 22nd April 2009, 10:13

Well strictly speaking the TZ isn't a roadbike so isn't legal, but as the engine is exactly the same as the TZR50 nobody is worried about it (so is the chassis, even the triple clamp has ign lock hole), there have been a few in the past, but really the Aprillia & Derbi engines are more advanced.

However the big bore kits can hardly be legal as they are not the original equipment manufacturer, they are made as essentially race kits. Some might then argue that they were made for the road. well. . . I can't see that these are anything other that aftermarket performance parts well in advance of bucket engines.

**Yow Ling** · 22nd April 2009, 15:26

The rules dont clearly define the difference between competition and performance parts. Is a Malosi 80cc cylinder for a rs50 a competition part, or a road part? 80cc in F4 with hot road parts ! But if you bore a stock part its ok . Maybe a clarification is needed as to what exactly competion is and if it includes performance parts , otherwise Dangerous may be forced to remove his performance rocker cover and performance billet carby trumpet thing.

**F5 Dave** · 22nd April 2009, 15:50

Yeah, in Post Classics they specifically mention MTC barrels etc. That precludes me rocking up on my Trinity 500 & racing post classics with it. I believe the intention of the bucket rules is that the engines are based on road going machines sold as a complete bike. Modify or build wot ya got. Not lets order up some swish aftermarket parts. Makes everything else a bit obsolete & removes the skill of tuning.

D's coloured carb inlet is free legality anyway being on a carb, if a little naff taste-wise. Rocker cover? Well, as a non performance part who cares?

**Sully60** · 22nd April 2009, 15:56

Originally Posted by F5 Dave

D's coloured carb inlet is free legality anyway being on a carb, if a little naff taste-wise. Rocker cover? Well, as a non performance part who cares?

But it's red it must be faster!
So his hair, oh wait, that fucks that arguement.

**SS90** · 23rd April 2009, 06:14

Originally Posted by F5 Dave

Well strictly speaking the TZ isn't a roadbike so isn't legal, but as the engine is exactly the same as the TZR50 nobody is worried about it

However the big bore kits can hardly be legal as they are not the original equipment manufacturer, they are made as essentially race kits. Some might then argue that they were made for the road. well. . . I can't see that these are anything other that aftermarket performance parts well in advance of bucket engines.

Ooops, sorry I meant TZR50!

I guess your right F5dave with the idea of a cylinder being a performance part (logically aftermarket cylinders are racing use (though the majority end up on the road!), and as such strictly speaking illegal......... but....just to play devils advocate, does anyone know if the TZR50 is steel lined (I think they are), in all seriousness it would not be too expensive to pay a machine shop to do the machining needed to "big bore it" (put a bigger liner in)

**F5 Dave** · 23rd April 2009, 09:14

They are steel lined I'm sure. Someone had bored his out to 60 or so to compete in F4, would need a new liner to get a big increase & a stroked crank to get further, but I suspect 80cc would be pushing it. Most big bore aftermarket kits go 65cc.

**SS90** · 23rd April 2009, 10:17

I had a look in a Polini catalogue I happen to have here, and it seemed to show that the 80cc kit they make was the same as almost every bloody 50cc up grade from Honda to derbi to Aprilia (etc etc etc) I had a look on Ebay, and the one I saw was advertised to fit the following (Metrakit make some as well)

FITS:
APRILIA MX 50 2t LC (MINARELLI AM 6 )APRILIA TUONO 50 2t LC (MINARELLI AM 6 ) APRILIA RS 50 2t LC (MINARELLI AM 3-4-5-6 ) BETA ENDURO RR 50 2t LC (MINARELLI AM 6 ) BETA SUPERMOTARD RR ALU 50 2t LC (MINARELLI AM 6 ) BETA SUPERMOTARD RR 50 2t LC (MINARELLI AM 6 ) FANTIC CABALLERO 50 2t LC (MINARELLI AM 6 )HM CRE - DERAPAGE 50 2t LC (MINARELLI AM 6 ) HUSQVARNA CH RACING 50 2t LC (MINARELLI AM 6 ) MALAGUTI XSM - XTM 50 2t LC (MINARELLI AM 6) MBK X-LIMIT 50 2t LC (MINARELLI AM 6)MBK X-POWER 50 2t LC (MINARELLI AM 6 ) PEUGEOT XPS 50 2t LC (MINARELLI AM 6 )PEUGEOT XR6 50 2t LC (MINARELLI AM 6 ) RIEJU RS2 50 2t LC (MINARELLI AM 6 )SHERCO HRD 50 2t LC (MINARELLI AM 6 )YAMAHA TZR 50 2t LC (MINARELLI AM 6 )

With exhaust and ignition I have seen a claim of "Up to" 19 Horsepower.... quite believable actually....Hmmm I wonder if you would be allowed....F5 dave made a good point though!

**F5 Dave** · 23rd April 2009, 10:44

Yeah the reason for commonality is the AM6(?) engine seems to be used in many diff derivatives, possibly even the 2nd generation TZR which has a round headed full crankcase induction engine, different to the 1st gen TZR. Perhaps Yam use this as well.

**TZ350** · 23rd April 2009, 22:18

Originally Posted by boostin

What is the ideal 2-stroke engine used in buckets?

Not really worried about the best stock one, but want to know which has the best potential to be modified.

Nothing can hold a candle to a Team ESE GP125!!!!

and

to the FZR150's, my boy get a Suzuki GP125 and build it to the ESE formula if you want speed and reliability.

**Sully60** · 23rd April 2009, 22:22

Originally Posted by TZ350

Nothing can hold a candle to a Team ESE GP125!!!!

and

If you even tried holding a candle close to the bike that is now Brens KV, the windrush as it passed you blow the flame and turn your GP into a ball of flame!

**TZ350** · 23rd April 2009, 22:25

Originally Posted by Sully60

If you even tried holding a candle close tothe bike that is now Brens KV, the windrush as it passed you would turn your GP into a ball of flame!

Yea, I know!.......but I just had to have my 15 seconds of fame.

Ive been found out allready .........

.

**Sully60** · 23rd April 2009, 22:27

Originally Posted by TZ350

Yea, I know! I just had to have my 15 seconds of fame.

.

Hey don't get me wrong, you're bike goes really well but that thing, faaarrrrout!

**TZ350** · 23rd April 2009, 22:32

NOooooo .........

I didn't realy expect anyone to believe me, I was just being a jack ass. There are one or two faaarrrrout! bikes that one realy has to admire and a few more good riders. I hope to get there one day myself.

**Mrs Busa Pete** · 24th April 2009, 22:10

iv got my tzr 125 well soon to be 100 and have got a frame for it now beter stop pissing around and get on with it 33hp power valved motor, down by one fith to 100 so 27hp at the 100cc mark in thery