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Mat Oxley 1986 IOM TT


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Messages - teazer

#16
Turning Wrenches / Re: RD350 wheels
January 12, 2024, 05:54:22 PM
Save yourself a ton of cash and get new spokes and rims from Mike's XS and build them yourself.
#17
I have to agree with Mark. An RZ easily makes 60hp with teeny tiny 26mm carbs.  30 - 34 are nice but depends on how you ride and what you are looking for.
#18
I'd speculate that it's a big end cage starting to break up. It could be a main bearing cage failing, but more likely it's a big end.
#19
So many choices. 
Long stroke: No
Water cooled: OK but not a lot of advantages over air cooled but if you need an RD top end, it's worth thinking about.  TZ top end is a lot of $$$ and pistons are hard to get and expensive
Air Cooled: Yes.  Fit an RD top end and have it ported
Chambers: Absolutely.  JL are beautiful, Spec2 are awesome, other choices as well
Reeds: YZ85 reed cages and open up the reed boxes to fit them with spacers
Long Rods: sure but not necessary for a street bike
Carbs: bore to 29.5mm or buy flatslides
Ignition: Vape, ignitech, Zeeltronic, HPI.  Vape is probably the best option.
Brakes: Upgraded disk rotor and caliper for sure.  Probably blue dots on an adapter
Suspension: Race tech or mike's XS gold valve emulators at least, or complete FZR400 front end with matched shocks at the rear.
Heads: minimum get squish corrected, or Vintage Performance or other aftermarket heads
#20
I hope we aren't confusing Keihn jet numbers with Mikuni large hex numbering.  Keihn jet are numbered according to their diameter IIRC, so a Keihin #138 is roughly equivalent to a 230 or so large hex mikuni.
#21
General Chatter / Re: RZ350 electronic black boxes
December 14, 2023, 06:24:18 PM
Thanks.  The sidestand switch is also not fitted but I would guess that it needs the side stand control unit because it's inked to the gear indicator as well ( I think).

Does anyone know if the Zeel power valve controller is an advantage to the performance?  Yamaha claim it is optimal but some Europeans seem to like changing the curve to a different slope or % open at certain revs table.
On our RS250 Aprilia Cup bikes, the power curve could move quite a bit with changes to when the valves opened.
#22
General Chatter / RZ350 electronic black boxes
December 14, 2023, 04:35:27 PM
I turned on the RZ this morning and the powervalve didn't do it usual cleaning routine.  Battery is fresh and charged so I suspect that the valves were sticky from lack of use. 

I removed the side covers and tank and cleaned all the PV servo connections and that seems to have cleared things, but I can't identify one of the black boxes under the tank.

I did find the CDI/ECU it's a 52Y-50 which seems to be correct for a 48H. And the P/V controller hiding under the seat beside the fuse box.

And the 3 wire old school flasher can was easy to locate, leaving two other units ahead of the CDI. One appears to be the side stand control unit.  It has 4 wire connector plus brown (power). The other has a 6 pin connector and might be the flasher cancelling unit but that's a guess.

The stock pipes are long gone so there's no catalytic convertor wiring or controller as far as I can tell.

Anyone tell for sure what the unit obscuring the coil is and the one to its right?
#23
General Chatter / Re: JL OW31 reproduction top end
December 14, 2023, 04:25:42 PM
Nope.  They look like a 3G3  350G model cylinder with reed boxes.  350 cylinders and heads are slightly wider that 750 parts, so you can't use a TZ350 head on a 750 cylinder and vice versa.  They have to be matched. I would suggest that they used the 350 design dimensions rather than 750 because there would potentially be a greater demand in Europe for that. As for port dimensions, I have no idea what they used, 3G3, TZ750D or something else.

Fondseca used to sell a similar part but again I have no data on ports or head dimensions.
#24
A full Nova transmission would be the perfect answer, but lottery winners only for that.  Even 4 individual gears are not cheap. A GS/GSX/GT hybrid might be best but whining is not all that common compared to jumping out of gear with work and rounded off engagement dogs.

When you have the motor out and stripped down, give me a call and let's work out your options.
#25
usually it's the second gear dogs that go, but I have a trans here missing al the teeth on 5th gear which is close to what you have there.

You have a few options:
- Buy a used trans off ebay etc and hope it's better than the one you have
- send me the two shafts and hope I can spare a pair of 5th gears to repair what you have- or
- Buy a complete transmission from a 78/79 8 valve GS750 and modify the output shaft and fit all GS750 gears
- Use second, 3rd and 5th gears on both shafts from the GS transmission and keep stock GT first gear.  4th gear did not change in terms of numbers of teeth across all years of GT and GS
- Or get a later 16 valve GS750 transmission and use the gears from that set with updated dog design and slip them onto a modified 8 valve GS750 shaft 
- Buy replacement gears from Nova Transmissions in the UK.

If yours is M or later the gear ratios changed so you have to make sure you get suitable gears.

BTW, a GT550 has many of the same gears as a GT750.  Shafts are different and so is second gear, driven, but that's another source of gears.
#26
I found a pair of ContiClassicAttacks at Partzilla and tehy arrived in 2 days.  Boy are teh carcasses stiff.  This could be fun trying to get them fitted. 

Odd that they are so much softer than 30 year old Metzlers.  Who would have thought... :whistle:  :umm:
#27
General Chatter / Re: OW31 Top End
November 29, 2023, 11:22:18 AM
Banshee is just an RZ350 without powervalves and with different gear ratios, so I wouldn't worry too much about that, but you already have RD400 cores to work with, so it seems to me that's the logical approach.

Now work out how much HP you want and if the RD400 cylinders will get you there or if the TZ750 top end can be made to work for your application with a spacer plate.  Both approaches will require a fair amount of time on the porting bench, so start calculating.

#28
More great input.  Thanks. 

I could not find the Pirelli MT75 in current Pirelli catalog but I did find the Sport Demon, but all the suitable rear tires are out of stock, so that bird won't fly.

Just after I decided on the Sport Demon, that hope was dashed.  Like the Avon sport tire I fitted to the Ducati and no matching rear available to match it.  I checked the AVON US site again and it says that RoadRider Mk11s are available.  I need to search again or stop wasting time and buy a pair of BT46s.

Or I could leave the 30 year old CompK's on for a few more years....


BT46 has the best range and not expensive.
#29
General Chatter / Re: OW31 Top End
November 28, 2023, 11:45:42 PM
I'm with JSpooner.  If I already had a solid 400 foundation, I would develop that as far as it can go with much bigger reeds and carbs and ports.

if I was starting from scratch I would seriously consider a built Banshee with say a 421 CPI or Athena top end or larger and build a motor that could make way more HP that a ported 400.

If I had access to a 6 port TZ350D/E top end, I would sit down and work out target port-time areas and then work out if a 62mm bottom end would work and where would the ports need to end up.

Either way, I would start by working out HP targets and work through what I would have to do to achieve them before I started to sink tons of cash into the project.  And if all budget becomes an issue as it does with all my projects, work out what you can do to a 400 to get as far as you need to go. Not a lot of point in sinking say $10 grand in a fully built banshee motor to win a $5 trophy and bragging rights.
#30
When I did a quick check online I don't see a lot of skinny 18" tires.

- Dunlop recommends the TT100/K81.  No sportmax in 18" sizes that would fit
- Avon race tires are no longer available and Roadrider 2 have limited availability and that is possibly old stock.
- Continental have some nice looking ContiAttacks but many sizes are out of stock.  Looks like I could go with a 90 front and 110 rear but they are a lot more $$$ than say a Bridgestone BT46
- Bridgestone BT46 seem to be available in 90/90 and 100/80 front and suitable rears
- Shiko 712 are probably available but not sure I want to go that way.
- Pirelli list a new version of the old Phantom tire we race with decades ago, but no suitable sizes
- Metzler lasertec is available in 110 front and 130 rear which is a bit too wide IMHO

Not sure what else is available.  Looks like many of us are using old tires  :whistle: