Hybrid Track Toy

[reggieperrin]

Ok, so...

This thread is more of a kick up the arse for me to get the project rolling...

I have;

An SZR660 rolling chassis, registered with a V5
For those that don't know, this is a version of the TZR125RR Belgarda that Yamaha dropped the XT660 lump into.
It has normal modern size wheels and runs 120/160 17" wheels so allowing sticky tyres..
Suspension is Paoli USD on the front and a beefy swingarm in the rear.

I've stripped it and removed the engine mount brackets ready to drop the YPVS engine into.
Engine mods will be;

+4mm hot rods crank
+2.0 bores with quite a hot tune.
lightweight rotor and Zeel ignition.
Athena cool head and domes to suit
TSA pipes, they might need a tweak to fit..
Carbs... Got a box of them to choose from..

I have a TZR 4DL plastic tank and some very lightweight bodywork to keep it svelte and skinny.
I will duplicate if possible the self supporting carbon rear seat units that I made when racing in ProTwins but might end up with a sub frame after all as it won't weigh much..
Loom and other parts will be kept minimal and I'm yet to decide on daytime or full MOT as the fairing I've chosen has headlight holes...

First job is to mount the engine and I have some inspiration for that..
The whole idea is to make something that is fun on the road but that I can also take on two stroke track days without fear of ruining years of hard work..

Will update with some pics soon...

Reg

[marsbar350]

crack on reggie the classic 2 stroke days are open for business
is nit done yet

[dusty350]

Hi Reg
Sounds a great project. Check out the "ugly betty" thread in the restoration section. That was a 4dl Belgarda frame with a valve engine fitted. A lot of clever engineering in that bike, though you wouldn't guess at first glance !!
Look forward to your progress.

Dusty😉

[reggieperrin]

Yep.. I remember that one Dusty..
Apparently, going by a french site that I've found, the SZR is about 2 inches wider than the TZR.
I thought they were the same but apparently not.
Should make putting the YPVS lump in a bit easier...

I'm really hoping for a stripped down look if possible, we'll see once it starts coming together..

[donkeychomp]

Can't wait for some pics this sounds like a cracking idea Reg!

Alex

[botty]

Looking forward to seeing progress on this one Reggie.

Doing the same spec engine for a Vj21 chassis

[dusty350]

Nearly all the pics I found were from French bike sites. They seem to do a lot of tzr/szr conversions. I know the one I had benefitted from a fair bit of work to get the engine sat right in the frame. I think my thread shows a lot of the mods but i will have pics if you need them

Dusty😉

[marrcel]

May be my next project.
I hope you log the sizes of the mounting brackets. 🤗
The adjusting of carbs will be between the frame bars is suspect. Is a reversed barrel possible?

[dusty350]

Reversing barrels can be a right pain in the butt. There is room for everything under the tank - battery, pv servo, electrical boxes etc - it looks cramped, but if you think it out, it all fits in;

DSCN2741 by dusty miller, on Flickr

The one I owned had a lot of mods done to get the engine sat correctly. If you need to correct the chain run Reg, I think I still have a spacer for the sprocket/hub. That in itself is quite an involved part but solves chain run issues

DSCN2650 by dusty miller, on Flickr

You will struggle to get to the carbs though - mine had a remote choke knob so you could operate that from the bars - you cant access it otherwise coz the frame spar is in the way.

Dusty

[marrcel]

Thanks for pics. Well not plug and play at the mo in my opinion. I have to reconsider🤔

[dusty350]

Definitely,definitely not plug and play I'm afraid

Dusty

[marrcel]

The thing is the szr is so cheap. So it is atractive. Just finished my 31k. It is better to jump on and make some miles on it. But i cant stop making new plans. Sounds familiair😋

[rich]

From what I can work out, the SZR swingarm is offset and must have a wider clearance on the sprocket side. I found this out when I used an SZR wheel in my Yamagamma as the sprocket was quite a way out from the wheel. A 2MA sprocket carrier is a direct fit though and brought the sprocket closer to the wheel and would line up perfectly in a YPVS frame

[Tobyjugs]

Didnt steelaway on this forum put a YPVS engine in a SZR?

[marrcel]

Mar 23, 2019 16:01:49 GMT 1 rich said:

From what I can work out, the SZR swingarm is offset and must have a wider clearance on the sprocket side. I found this out when I used an SZR wheel in my Yamagamma as the sprocket was quite a way out from the wheel. A 2MA sprocket carrier is a direct fit though and brought the sprocket closer to the wheel and would line up perfectly in a YPVS frame

I have szr wheel in 31k swinger. So familiair with that. Which is easy peasy. I made a thread on that. I used the 4su sprocket carrier from the szr.

[Tobyjugs]

I used the SZR rear wheel as well. Its made by Brembo and not too heavy. The master cylinder also works well on a standard 350LC set up.

[marrcel]

TZR 350
r.tapatalk.com/shareLink?share_fid=106900&share_tid=30010&url=https%3A%2F%2Frdlccrazy%2Eproboards%2Ecom%2Fthread%2F30010&share_type=t
This the thread from steelaway. First the popcorn🤗🤔