Tyz's

[craig10]

Can anyone tell me which are the better TYZ's?. My mate has a '96 purple wheeler which is really soft on the power and so grips like hell. I was talking to someone who has had a few and reckons the later ones have more aggressive engines so break traction more easily. Also, what is the Scorpa engine like compared to the TYZ's?.

I fancy something with a bulletproof reputation.

Thanks for any info

[woody]

No takers so I'll have a go then.

Purple wheel model is actually a 94/95 and they are generally thought of as the best in terms of power delivery and grip. Biggest problem, depending on how tall you are, is the high, in current terms, standard footrest position but this can obviously be resolved by moving them.

The 96 bike was the first to have the exhaust manifold with the canister on it and was probably a bit sharper as you have said. I had a new 98 bike and it was too zippy off the bottom. Had to give it to Nigel Birkett to soften off with some porting work and it was fantastic after that. Gripped like hell. 96 onward also had a 5mm, maybe 10? spacer under the top yolk to higher the bar position.

However, as the youngest bike is now about 6 years old they are all generally pretty soft in their power delivery as they've lost any sharpness they may have had. Don't interperate this as flat or gutless though because they aren't. They are a tremendously torquey engine, just very manageable off the throttle which means you aren't 'chasing' them through sections. You can pretty well ride them without always riding the clutch, even in higher gears. The engine will pull any gear you want they are that torquey.

I haven't owned a Scorpa but I've had a go on a few and in my opinion (and that is all it is) the Scorpa engine doesn't have the same torquey flexible feel as the TYZ. The Scorpas I have ridden still had a softish delivery but they weren't as smooth around say nil to quarter throttle and had that distinctive slightly jerkey 'beat' that most modern bikes have if you ride slowly without the clutch. You can drop a TYZ down to nothing in a section, then pull away again with no snatch, jerkiness etc. even in 3rd or 4th gear. It's power delivery just seems so linear all the way through, no sudden bursts or surges, just responds precisely to the throttle. Beautiful engine - again in my opinion. The difference is probably only down to the different exhaust systems.

Just to clarify, I'm not saying the Scorpa isn't as good, I just prefer the feel of the TYZ motor as it feels more torquey to me.

[craig10]

Thanks for that Woody, I feel that when I ride my mates one, there is none of the snatch/jerkiness that I get off my own 200ccRev-3 when cracking the throttle on from zero in a section.

As you seem to know your TYZ's, any ideas on increasing fuel capacity?. Someone suggested to me that you can tap into the 2 top frame spars and use them, ever heard of that one?. Ever run out of fuel at the Scottish?.

Thanks,

Craig

[woody]

Ever run out of fuel at the Scottish?.

Oh Yes......... last year. First day before the first group of sections. Not the fuel capacity of the bike to blame though. An Arctic was parked up on the pavement obscuring the flags to turn us into a junction. I didn't know to turn off there so sailed past and went a good way before realising something was wrong. U-turned but ran out before I reached the fuel check. A long push and finally blagged some neat fuel of a farmer to get to the fuel check. Great bloody start to the week. Guy on a Rev 3 was with me and did the same but his bike went a bit further than mine before he ran out.

Mishaps like that aside, the fuel capacity on the TYZ is enough to get you around without increasing it. You can put extra fuel in the frame. The bike I have at the moment has been done but without stripping it can't see exactly how it is done and I've never used the extra capacity - and no, it isn't the bike I rode in last year's. The holes on the inside of the frame spars are welded up, A tap/outlet is put into the bottom of the cross-brace that runs between the spars by the carburettor and presumably is connected to the pipe from the tank to carb. There is a breather in the top of the frame just in front of the headstock. What I can't work out is how the fuel gets into the frame in the first place, unless it is filled through this breather. I shouldn't worry though a it will get round on the standard tank.

[craig10]

Thanks Woody. I suspect that the method of getting the fuel into the frame space would be to fit a tee piece between the fuel tank and petrol tap then connect the tee to the connection at the bottom of the spars. That way the level would equalise with the fuel tank level, but it would take a while to fully fuel up, depanding on the bore of the cross connections.

The reason I ask is I thought it would make a good trail bike with a bit more fuel capacity.

Cheers,

Craig

[woody]

A mate of mine who is an absolutely brilliant fabricator/welder once made a replacement fuel tank for another mate's TYZ for the Scottish. It fitted perfectly, the plastic cover still fitted correctly and I think it gave almost an extra litre capacity. It filled every bit of available space under the tank cover and even though it couldn't be seen was still beautifully made. I borrowed it myself a few years back to do the SSDT. Unfortunately it has bee sold on a couple of times in recent years and we don't know who has it now.

Another way of increasing the capacity is to make a small supplementary tank that fits onto the front forks, where the number board fits. Same mate made a few of these some years back as well for local riders. They were the same size as the number board but about a couple of inches deep and again took around a litre of fuel. If you know someone who can alloy weld and fabricate, this would be fairly easy to make as it is just rectangular in shape. Just needs a filler cap and tap outlet and a fuel line to the carb. I think some firm was selling something similar a few years ago as a drinks carrier as well - same principle, except it wasn't connected to the carb...

[craig10]

Woody, saw the very same thing on a few bikes at this years SSDT.

There's a 1/2 litre version which is actually a drinks container, or you can get a Hebo fuel version, 1.2ltr, from the Lewisport USA web site for $75.

They have an air vent and a siphon pipe on them, you connect the siphon pipe to the normal fuel tank vent, as fuel is used up it's drawn from the auxiliary tank into the normal tank, the air coming in at the auxy tank atmospheric vent.