Calling all MB100 tuners and bucket engineers

**FROSTY:Me** · 6th August 2005, 10:00

In my opinion bucket racers need to be built to suit the track they are mostly going to be raced on.
I've seen the welly bucket track and of course Ive raced at Mt wellington in auckland.
Totally different tracks.
Im wellywood you seem to have bigger wider corners and a couple of straights where a good two stroke could really get well wound up.
Mt wellington (full circuit) only has one straight and one high speed corner. 75-80% of the track is corners. That seems to suit a tourquey 4 stroke better.
Also a bigger track would better suit a bigger chasis and better brakes whereas a smaller trach seems to suit a quicker steering bike.
Anyhoo thats my opinion --and I must say I havent raced mt wellington in at least 6 years so I'm probably well out of date.

**Hailwood** · 6th August 2005, 15:42

If anyone is interested I have a MB100 rolling chassis sitting in my backyard..has RS125 rims..no engine....if anyone wants it let me know..am open to all offers.....

**speedpro** · 6th August 2005, 23:30

My bikes are already in Wellywood and I will be too by the end of August. Just hope I have time to go and play.

Looking to get accommodation for family of three in Wainuiomata if anyone knows of a nice place to rent. Hine Road looks nice.

**steve k** · 18th August 2005, 13:23

Have just taken posession of a mb100 motor, 6 spd gearbox out of an mb50 and also a new conrod kit. so hopefully in the not to distant future (wife and kids allowing) i shall be racin

**speedpro** · 18th August 2005, 13:39

Originally Posted by steve k

Have just taken posession of a mb100 motor, 6 spd gearbox out of an mb50 and also a new conrod kit. so hopefully in the not to distant future (wife and kids allowing) i shall be racin

Do NOT use "Long" brand conrods, F5 will back me up on this. Genuine Honda rods are very good and I seem to recall hearing good words about pro-X as well. If your kit is Long brand, place it carefully in the bin.

The other thing is, if you have the motor apart don't be tempted to take the balance shaft out. I've never tried it (yet) but those that have tell me it'll vibrate like a vibrating thing.

**TonyB** · 18th August 2005, 13:46

Originally Posted by FROSTY

75-80% of the track is corners. That seems to suit a tourquey 4 stroke better.

Hmm, I've done one meeting on my GP125- it has an RZ250 pipe on it, and a pissy 22mm carb. It seems to pull much harder low down than most of the other bikes, but it has about the same top end as Dangerous' and K14's CB125T's. This suits me well at the moment because the handling, tyres (and yes, rider) SUCK, so I can pull out of the corners well enough to do OK. Surely that combo with sorted handling would make a decent short track bucket?

**steve k** · 18th August 2005, 16:28

Originally Posted by speedpro

Do NOT use "Long" brand conrods, F5 will back me up on this. Genuine Honda rods are very good and I seem to recall hearing good words about pro-X as well. If your kit is Long brand, place it carefully in the bin.

The other thing is, if you have the motor apart don't be tempted to take the balance shaft out. I've never tried it (yet) but those that have tell me it'll vibrate like a vibrating thing.

thanks for the info speedpro. will check this out. balance shaft will be staying in. cheers

**F5 Dave** · 18th August 2005, 16:40

Yeah my MB50 one snapped, neatly ventilating the crankcase. Maybe the 100 size ones are better, but I doubt it.

I’ve ridden some pretty vibey MB100s. Strangely my MB50 I pulled the balancer out & it was smooth. Also the H100, which is essentially the MB motor in this regard mine came with the balancer disconnected (bearing died) it wasn’t vibey at all, even in a 2 hr, maybe the padded seat & big bars isolated you. Dave D's one vibed real bad without it. As I've said, be real cautious about those front engine mounts. They aren't used on MBs or H100s. Need loose rubber mount or don't use. Vibes will crack the crankcase.

Those forks on the GP feel real disconnected from the frame. Worse if your seating position is too far back.

**TonyB** · 18th August 2005, 16:45

Originally Posted by F5 Dave

Those forks on the GP feel real disconnected from the frame. Worse if your seating position is too far back.

well compared to the shocks on mine, the forks are brilliant!
If the forks are as bad as you say, and moving back makes them worse, then I wonder if jacking up the rear end will make them feel better by transferring some weight foward?

**diesel pig** · 18th August 2005, 21:41

I agree about the balancer speedpro I rode a MB without one and watched the steering stem nut undo from the vibes thats how bad it was but a hot MB50 I rode that didn't have one wasn't that bad interestly.
Ah speedpro and F5 would you be interested in a two day meet at Blenheim on labour weekend?

**speedpro** · 18th August 2005, 22:06

Originally Posted by diesel pig

Ah speedpro and F5 would you be interested in a two day meet at Blenheim on labour weekend?

If I can manage to get away from the produce department, but very hard to say at the moment seeing as I haven't even started the new job yet.

Love that track.

**Brian d marge** · 19th August 2005, 01:58

Originally Posted by TonyB

Hmm, I've done one meeting on my GP125- it has an RZ250 pipe on it, and a pissy 22mm carb. It seems to pull much harder low down than most of the other bikes, but it has about the same top end as Dangerous' and K14's CB125T's. This suits me well at the moment because the handling, tyres (and yes, rider) SUCK, so I can pull out of the corners well enough to do OK. Surely that combo with sorted handling would make a decent short track bucket?

That pissy little carb is doing a wonderfull job on atomising the fuel and will flow almost as much at top end ,,( and Just How long do you stay on full throotle on a cart track???) ....dont be tempted luke ...dont join the big carb side ,, you lose all metering strength down low ,,,
My mx cr250 only has a 26mm carb on it ,,and I will poss go a few mm lower as I need the punch on tight and twisty tracks ,,,

Oh and theres a lot of them about as its usually the first thing people throw out ,,,,

Stephen

**F5 Dave** · 19th August 2005, 09:23

Originally Posted by diesel pig

Ah speedpro and F5 would you be interested in a two day meet at Blenheim on labour weekend?

Make it official & I'll book my ferry tickets!

**TonyB** · 19th August 2005, 10:00

Originally Posted by Brian d'marge

That pissy little carb is doing a wonderfull job on atomising the fuel and will flow almost as much at top end ,,( and Just How long do you stay on full throotle on a cart track???) ....dont be tempted luke ...dont join the big carb side ,, you lose all metering strength down low ,,,
My mx cr250 only has a 26mm carb on it ,,and I will poss go a few mm lower as I need the punch on tight and twisty tracks ,,,

Oh and theres a lot of them about as its usually the first thing people throw out ,,,,

Stephen

Yeh, I'm not feeling tempted to change it just yet. Might go to 24mm which is all I'm allowed under the rules, but as long as I can get in amongst it and have some good racing, I'm happy. We race on full sized circuits down here, but I still don't think the carb is slowing me down much- maybe a little in the top end. But then all I've done is cut the header off an RZ250 pipe, and push the pipe over the standard GP100 header. If I push it on a bit more I should get some more top end in theory.... imagine what it would take to do that to a 4 stroke.... It's actually quite laughable how well it goes considering the fact it's been slapped together.... and then of course there's my mechanical 'ability'...