The story of Tenzing the Super Tenere

[warewolf]

Nice ride!

Interesting that as the pre-cursor to the more road-ified TDM850 that I had, this thing cures most of the TDM's ills, namely poor off-road prowess due to wheel & tyre choice.

I'm sure it will be a lot of fun

[SDU]

Congrats on your new toy R! Hope you get it sorted to your specs in no time.

[cooneyr]

Nice ride!

Interesting that as the pre-cursor to the more road-ified TDM850 that I had, this thing cures most of the TDM's ills, namely poor off-road prowess due to wheel & tyre choice.

I'm sure it will be a lot of fun

Here's hoping

Congrats on your new toy R! Hope you get it sorted to your specs in no time.

Thanks S. Being at home to study and having long lunch breaks while being bad for getting uni work done certainly helps with bike prep - just dont tell anybody

Couple of pics of progress so far.

1. New lockable tail rack tool box lid
2. Tool box lid again
3. New bars, bar risers, grips, bark busters and mirrors with leavers adjusted to suit me (good thing the brake lever is span adjustable cause it was miles away from the bar)
4. Bars from the front side

Cheers R

[NordieBoy]

Looks like it needs to get dirty...

[cooneyr]

Looks like it needs to get dirty...

Indeed - just need time to do it. Tyres should be turning up soon - don't really rate the slicky things, what ever they are, on it at the moment.

Cheers R

[426crasher]

Tenzing is the latest edition to the family. He is a 1991 Yamaha XTZ750 Super Tenere.

Hmmm... this takes me back a bit. I had a 91 model, bought it in 93 and sold it in 96, and it proved to be totaly reliable. Did a little bit off road with it but for my height and 76kg frame it was just to big. Took it around Europe twice whch turned out to show it's real strength... monster mile eating ability...Found mine to be a bit thirsty for a 750 twin but i certainly enjoyed my 50000kms with her. Never had an issue with this disc shrouds and the only uglys that i can remember was the sarter motors were a bit fragile and quite a few suffered from collapsed rear wheel bearings.
I'm quite eager to see one on the dirt again, possibly 2...
Good luck with the resto.

[cooneyr]

Hmmm... this takes me back a bit. I had a 91 model, bought it in 93 and sold it in 96, and it proved to be totaly reliable. Did a little bit off road with it but for my height and 76kg frame it was just to big. Took it around Europe twice whch turned out to show it's real strength... monster mile eating ability...Found mine to be a bit thirsty for a 750 twin but i certainly enjoyed my 50000kms with her. Never had an issue with this disc shrouds and the only uglys that i can remember was the sarter motors were a bit fragile and quite a few suffered from collapsed rear wheel bearings.
I'm quite eager to see one on the dirt again, possibly 2...
Good luck with the resto.

Cool now we know who to come and annoy if we need any advice

Fuel consumption seems to be a bit of a nemisis of these things. Sounds like it is mostly associated with worn needle jets (emulsion tubes) seeing that the carbies are down drafts i.e. gravity helps wear things rather fast. About $100nz for new nickel coated needle jets that supposedly last much much longer than the stock brass ones (which can die in as little as 10k kms).

El's bike is currently using about 10l per 120kms (12km/l) while taking it easy, which is shocking fuel consumption for a bike. I think the carbies will be coming out ASAP. Mine supposedly has had the needle jet replaced but I've not been on long enough ride to figure out the fuel consumption yet so cant be sure.

Cheers R

[warewolf]

Ah... I have some experience with that problem on my Triumph.

The BST36's on the Triumph are legendarily bad, and one reason they swapped to Keihin in 1998. I have just tracked down a source of the replacement parts - that Triumph and Suzuki don't sell. They don't even show it as a separate part in their exploded diagrams. And Mikuni won't sell OEM carb parts to the public. So bad luck if you have a Mikuni-carbed Triumph or Suzuki GSX-R750/1100.

What are the carbs that are on Tenzing? Oh, look, they are the Mikuni BDST38's... You might be lucky, Yamaha might still sell them. They are listed on BikeBandit for the 1992 TDM, couldn't find the XTZ quickly. Part #21 in 'carburetor' is what you need.

What happens is the vacuum pulses shake the carb throttle valve (piston) back and forth. This uses the needle as a saw in the the needle jet (emulsion tube) which ovalises the orifice. So the bike runs horribly rich because the round (or less, if it is worn too) needle can no longer block the needle jet like it ought to, and nothing you can do will tune that out. Eventually the throttle valve guide (aka piston guide or plastic throttle body insert) will wear significantly, rapidly crapping out any replacement needles and jets.

My last set of needles & jets lasted maybe 5000km before giving trouble again. Fuel economy should be around 6.0 L/100km, runs at about 9+ L/100km sometimes now. So I would strongly suggest buying replacement throttle valve guides, FactoryPro emulsion tubes, and possibly new needles - unless they are spotless. This is one fix that falls into the do-it-now-and-reap-the-benefits category, despite the cost. And since you need two sets, you can save on postage!

Read more at FactoryPro Tuning: Worn Needle Jets and Mikuni emulsion tubes / needle jets. Gee whizz, they quote the TDM/TRX (same carb as XTZ) as a bad example!! (The HDJ animated gifs are worth a look, and why I recommend their emulsion tubes.)

You can thank me later!

[cooneyr]

El (ma bro) is trying to find out if Factory Pro does needles as well (not clear what is in their Ti kits on their web page). If they do then he will be getting needles and needle jets from them otherwise just the needle jets and new stock needles. Price of these parts seems pretty cheep really.

I hadn't read anything about the throttle valve guides wearing - better check that one out as well, makes sense.

When I finally get to go for a ride an check out what the fuel consumption is like I'll make a decision on this, but bro is defiantly into this ASAP. Thanks for the info.

Cheers R

[warewolf]

Flick an email to FactoryPro, Marc is very helpful. The Ti kits are usually Ti-needle-based, but include slide springs, body screws, jets etc. The TDM kit specifically states Ti needle; it's probably the same kit.

He talks about the guides wearing on the the Mikuni page.

[El scooto]

Have been emailing JMC DYNO. A tuning place in Auckland that are the distributors in NZ. Needle jets are $35 each and they don't do needles. He suggests using stock ones. So will give this a go and probably give the valve guides a go to as it does make sense.

Cheer

PS now I just need time to do it!!

[cooneyr]

Got to go for a blat along my favorite route to work and my first solo ride in the dry today. For a heavy beast it corners well, feels way more stable than the DR ever did. This is probably helped by the fact that the shock is rather flogged out and rear is rather low and it still has the icky slicky things on.

Plenty of grin factor this morning

Cheers R

[warewolf]

I think you need to update your avatar...

[cooneyr]

I think you need to update your avatar...

Oh yeh - need some new pictures

Cheers R

[426crasher]

For a heavy beast it corners well...

Mine handled fabbo on the black stuff then again it was only 2 years old,in mint nick and only 5000 miles on it when i bought it. Doe's yours only run on one cylinder for about 10 seconds when started for the first time each morning? Mine did like clockwork and no one ever managed to sort it.