MB100 development

**Buddha#81:Me** · 30th September 2011, 11:48

Originally Posted by F5 Dave

Are you sure? Dave D said he went through the liner trying to bore it. The steel is a wasted shape with ally cast over so it is hard to tell where the least thickness is.

if you have a spare barrel bring it to the BOB i can ultasonic measure the thickness for you.

**koba** · 30th September 2011, 12:19

Originally Posted by Buddha#81

if you have a spare barrel bring it to the BOB i can ultasonic measure the thickness for you.

Phoo aye!

**Buddha#81:Me** · 30th September 2011, 12:47

Originally Posted by koba

Phoo aye!

Flash as down here!

**husaberg** · 30th September 2011, 17:13

Originally Posted by F5 Dave

Are you sure? Dave D said he went through the liner trying to bore it. The steel is a wasted shape with ally cast over so it is hard to tell where the least thickness is.

Very sure, if all the net research stakes up and it is reasonably collaberated on more than a couple of sites In fact I may be willing to bet a R6 rear caliper on it. Dave?
Do you want a picture?

Husaberg PS the 125 can be done using a non competition barrel with a 57mm piston, its available from new too.

Read the post again before you make the bet Dave. Because I love R6 Rear calipers.

PS Who is Dave D?

**Henk** · 30th September 2011, 19:06

Originally Posted by husaberg

PS Who is Dave D?

Dave Diprose

**Hilleye** · 30th September 2011, 20:30

Originally Posted by husaberg

.

The MB50 ignition has a high speed retard function the MB100 has a advancing ignition.

Please post a pic of the full bike I can't figure out the frame.

Electrics are a mystery to me. Do I want and advancing or retarding ignition? I assume advancing.

Has anyone just bunged on an RG150 or NSR125 CDI and seen what happens? What does one of the programmable ignitions cost?

Will do a full bike pick with inlet and cylinder photos.

**husaberg** · 30th September 2011, 20:47

Originally Posted by Hilleye

Electrics are a mystery to me. Do I want and advancing or retarding ignition? I assume advancing.

Has anyone just bunged on an RG150 or NSR125 CDI and seen what happens? What does one of the programmable ignitions cost?

Will do a full bike pick with inlet and cylinder photos.

I used to think I knew the answer to that question. Now I am not so sure.
The more that I learn the more I realise that I didn't know as much as I thought I did.

Get Wob to answer the ignition question and he will be able to obtain a Ignitech ignition for you. I have sent him a link to the thread.

Ps I have tried a static CDI unit on the MB I didn't run that well as it broke down at revs as it was from a dirty 4 stroke that ran at half engine speed and couldn't hack the pace.
There is a page which I will post that explains the ins and out of basic ignition and winding coils etc http://www.btinternet.com/~jhpart/bkns125a.htm

**speedpro** · 30th September 2011, 22:03

I've fitted various ignitions over the years and they have all seemed to be good. I've now got an Ignitech. Funny thing is that I can now alter the timing to anything the bike wants and it seems that apart from one little point way up in the powerband a flat timing curve is what it wants. Fixed timing would seem to be OK, as tested on the dyno on my motor.

**speedpro** · 30th September 2011, 22:05

Regarding oversizes, Dave D tried a 54mm piston in a MB100 and ended up going through the sleeve into aluminium, just.

**TZ350** · 1st October 2011, 07:30

Originally Posted by husaberg

PS the 125 can be done using a non competition barrel with a 57mm piston its available from new too.

"From New" could this be the clue?

**husaberg** · 1st October 2011, 07:42

Originally Posted by TZ350

"From New" could this be the clue?

The highlighted bit was intended to give it away.
I may have been a bit too subtle. I wonder if I have let some sort of cat out of the bag.
As Dave has for some reason got his back up Plan already in place In the event that if for some reason just in case his 100 is not ready for Taupo?.http://http://www.kiwibiker.co.nz/fo...r-Taupo/page10 Was this it.

I was aware Honda has made MB5/MB50 and MT variant and I was aware of the MB80/MB8 models as well as the of course the H100/Mb100 Models.
Well I had always assumed the MB8 was a big bore 50 well it appears to be a debored 100 according to the pretty much all the specs I have been able to find this makes the MB8 a 45mm x 49.5mm = 78cc.
I know the net is full of duff info but this seems to be highly likely to be correct as it is repeated consistently.
I can see this info is a little boring but there is big bore kits that are not competition parts available for the MB8 one of them see pic below offers a 57mm kit (it will I guess) be on a low state of tune but has a nice looking piston.(which could be a display pic)

http://www.moped-museum.de/sonstige-...da-mb5-mb8.htm
http://www.50cc.nl/frameset_eng.htm
http://www.scootparts.nl/Cylinder-At...product/66715/
http://translate.google.co.nz/transl...26prmd%3Dimvns

Re the limit for the STD cylinder the Ryteching site (which sadly looks like it has died now, but I have saved some info off it). Used to list a 53mm OS piston for the MB100.
That I would guess is the limit for the STD cylinder.
(Ryteching Info now posted)
I have found some bits of info on this site are wrong as in some typos but it was a great site for looking for specs of pistons.

As you guys are intending to measure a MB100 cylinder measure the h100 as well as there are some subtle changes and a few not so subtle design detail differences between the engines.

The Japenese BTW are credited with the bonding process (I would say they perfected it for mass production) but I believe invented or developed at least by the brits in the 50's... Wellworthy? and probably earlier by the Yanks. There seems to be a patent in 1929.
It was common of Brit race 4 strokes. Alfin. Including the Villiers Starmaker 2 stroke.

The sleeve is odd shaped (sometimes corrugated for want of a better description) mostly I believe to increase the surface area and make sure it stays in place and I believe its is thicker at the spigot to provide support at the base which isn't as well supported.

**F5 Dave** · 1st October 2011, 07:56

I've known Dave for well over 20 years & if he says it goes through, then it goes through. He isn't one to ignore details & if anyone has met him they'll know what I mean. Big bore kits may have sleeves, even new barrels, who knows.

**TZ350** · 1st October 2011, 08:25

Yes, I have found that too, going 2mm OS is ok 4 is dodgy and I have gone through the liner on RD cylinders this way. It seems that the alloy/liner bonding process allows the Japanese to run very thin liners and the liners are wasted too or have ripples around the outsides and I wound up with a series of rings in my RD cylinder. You can often see the liner in the spigot is thicker than the liner you can see in the port window.

Husenburgs special completely Bucket legal aftermarket MB 57mm oversize cylinder looks interesting, its truly another gem gleened from the mysterious internet.

**dangerous** · 1st October 2011, 08:42

Originally Posted by Hilleye

Alright so I'm definitely wrong about the rings. Its actually been a while since I had the barrel off and I appear to have made a mistake. I therefore retract any statements that infer the previous owner being dodgy

That be me... Havent read all so fill me in, all i can say is i did no work personaly to the engine see bren chch for that.
Over the time i had the bike it went beter and beter till i decided it was time for a freshen up as it had done a few seasons.
As yl said the oll boy that does our re bores wasent happy with the exhaust port being squared of, he was worried it might hook a ring up (it never did) so in order for him to hone for a fresh piston brenn chch had a go at the port.
Un fourtnuatly imho this changed the port timing to much and i never got it tuned right again, yes i did all the carb tampering to the best of my knolage. I would look at starting again with a new barrel.