ESE's works engine tuner

[FastFred]

........... Attachment 321590

................. So True

[arc100]

Can anyone help me out?

I'm looking for a port angle and dimensions map for a HH TZ250 84 cylinder.

Thanks.

[F5 Dave]

I've got one right here, . . . no wait, its a box of cereal. Sorry about that.

[husaberg]

Wob will probably remember a conversation years ago about Roberts carbs.
I found these pics today.
(later)
later, traditional Keihins

Vs what I suspect are the original engines Roberts carbs.

[wobbly]

Now that is really interesting.
I have never seen the early Roberts engine ( upside down compared to what was raced, and the BSL tripple with 2 up ) but they found as I did that the Keihins ( read zillion dollar )
when run back to front,would pull the floats down on the fulcrums and flood under brakes.
So they went back to the original carbs that were pump around with a weir system in the bowl.

[TZ350]

.

Tonight we were making great progress with the 50, the Team were pulling great runs, changing jets and tweaking the ignition.

Just when we had done all the runs and finished up with the best power and curve then someone noticed it had all been done with the choke on, flipping it off and it all turned to mush .....Bugger ... LOL ... another day tomorrow I guess.

[chrisc]

Hahaha claaassssiiiccc! Did you change the ignition on the 50 Rob? Was that the problem?

[2T Institute]

Still to this day suffer sore neck from the high side.

The white ceramic balls are Zirconiated and cannot handle loads or shock, proper ceramic bearings have black balls by Cerbec made from Silicon nitride. That has never happend with Cerbec/St Gobain balls. I have heard stories of them being hit with a hammer on a steel plate and only mark a little. Have used them for ages and back for buck wheel bearings make a massive difference. A bike fitted with ceramic wheel bearing is easier to push around in gear with the clutch in than a bike without in neutral.

[Frits Overmars]

Just when we had done all the runs and finished up with the best power and curve then someone noticed it had all been done with the choke on, flipping it off and it all turned to mush .....

I know the experience; we once had it on the track. After a record practice lap somebody noticed the choke was still on.
Exuberance! Rectifying this would certainly bring another second or two!
You guessed it: with the choke off the rider never managed to equal his record lap. He said the power came in much more friendly when the choke was on.

A bike fitted with ceramic wheel bearing is easier to push around in gear with the clutch in than a bike without in neutral.

I like to think I have an open mind, but not that open....

[TZ350]

I know the experience; we once had it on the track. After a record practice lap somebody noticed the choke was still on.
Exuberance! Rectifying this would certainly bring another second or two! You guessed it: with the choke off the rider never managed to equal his record lap. He said the power came in much more friendly when the choke was on.

We were tempted to just leave the choke on, and use it like that .... .... still it showed up some interesting things about the fueling.

Hahaha claaassssiiiccc! Did you change the ignition on the 50 Rob? Was that the problem?

Pretty obvious it was electrical and to find the fault we did it scientifically, changed one part at a time, first the CDI, then the Stator next was going to be the coil, turned out to be the new spark plug...... .....

[wobbly]

Frits, you need to purchase some mind opening substances readily available near you.
I have been told by several race teams that bikes fitted with ceramic wheel bearings will coast twice as far after a plug chop.
Now I am as skeptical as all hell, but they seem more than happy to pay silly money for the damn things,so I should just cough up and do a dyno run down test.
I suppose the metal shield type bearings wont have near the rolling friction of rubber lip types, but that provides very little protection from ingress of shit
and water - so I dont know what to do about that as the bearings are so expensive you simply dont want to ruin them by not sealing them properly.
Whats the go Lozza?

[Bert]

The white ceramic balls are Zirconiated and cannot handle loads or shock, proper ceramic bearings have black balls by Cerbec made from Silicon nitride. That has never happend with Cerbec/St Gobain balls. I have heard stories of them being hit with a hammer on a steel plate and only mark a little. Have used them for ages and back for buck wheel bearings make a massive difference. A bike fitted with ceramic wheel bearing is easier to push around in gear with the clutch in than a bike without in neutral.

Zirconiated ceramic, yip, I did have a bit of fun trying the replicate the collapse (on the other bearing) with a sledge hammer. But unsuccessfully. So it's mounted on the wall next to the large number of Pistons...

Silicon nitride seems likely for the next attempt - once we fix the cylinder issue.

[2T Institute]

I like to think I have an open mind, but not that open....

Well the bikes are here whenever your ready to try Frits Wob have run the microblues in all types of conditions including very harsh conditons(make of that what you will) with seals. Use 4 drops of oil a year. Ran then in karts with a great results and yes they will coast for a long time top speeds are not increased notably but the time taken to get there is less. I had a long conversation with a coach of the NSW Institute of Sport junior cycling team about ceramics and what they do for a humble push bike (concealed motors apparently work best ) was metres on a velodrome and higher average kmph on the road(wheels and crankset)

[peewee]

if you leave off the wheel hub seals it reduces the rolling friction quit a bit. then just use any type of bearing with rubber seals covering the balls. dirt or water shouldn't be much of a problem unless your off road. ive already experimentd with this. without hub seals causing friction on the axle spacer it rolls much easier

[Grumph]

if you leave off the wheel hub seals it reduces the rolling friction quit a bit. then just use any type of bearing with rubber seals covering the balls. dirt or water shouldn't be much of a problem unless your off road. ive already experimentd with this. without hub seals causing friction on the axle spacer it rolls much easier

Leaving the seals off and using oil as a lube for wheel bearings is an old trick. It goes back to short circuit racing where essential maintenance between meetings was wheels out and wash bearings. Easier to do in the days where only one tyre type meant only one set of wheels...