Honda MB5 Mods

Has anyone done any mods to the Honda MB5. I know there are lots of things that can be done. I'm just looking to do it a little at a time. I think I need to get a new carb, so I would prefer to go ahead and buy a bigger one in preparation for the future. Will that work with the rest of the stock parts? Or should I buy another stock carb for now?

My bike is a 1981 European Honda MB5. It is restricted and I am looking to EVENTUALLY change out the carb, reeds/block, cylinder, pipe, 6-spd gearbox, racing CDI, and air filter. I am hoping that I can eventually get this thing to rip. Can anyone shed some light on this process? Is there a good order to do this? Any help would be much appreciated.

Thanks!

DH

Re: Honda MB5 Mods

VM20, new intake, boyesen dual stage reeds.

Re: Honda MB5 Mods

All of your restriction is more or less in the cylinder ports and the exhaust, so if it were me, I would start with those. I have a stock cylinder, exhaust and carb if you're interested in them.

the stuff mentioned above me would be a great upgrade for an American mb5 cylinder, but will do absolutely zero for you.

Re: Honda MB5 Mods

Josh Besecker /

Kit it, and keep the stock carb, just get a 92 jet for it. Down the road, homoet 70cc exhaust.... I'd mess around more with gearing than a racing cdi... How much do you weigh? Can you sacrifice some torque for top speed?? if so, re-gear. Clutch and 6-speed are more advanced tuning options (ie, not for the faint of heart)...swapping out the reed block will make you happier too...I just put a Top 8petal in my MB5... exhaust the aforementioned options first.

Re: Honda MB5 Mods

I thought all of the restriction in the European MB5 was in the air intake? I'm totally fine with being wrong, but I just want to make sure before I start throwing money around. Are your parts in good shape? How much are you asking for them?

If anyone else has any other insight let me know. Thanks!

Re: Honda MB5 Mods

I see. Thanks for that insight. I'll definitely be saving the clutch and gearbox for the future when I am really bored. I won't worry about the racing CDI for a while either.

Can I use a kit with a stock exhaust? Or will that really hinder the performance? And will my European carb (smaller than American 13mm vs 16mm, I think) keep up with the 70cc kit? I just want to make sure all the parts are compatible.

Unfortunately I weigh 210lbs. I know I am slightly large for the moped business, but I love these little bikes (and I am trying to drop some weight too). That said, torque wins over top speed right now, but I will definitely keep that in mind.

Thanks!

Re: Honda MB5 Mods

Josh Besecker /

If his parts aren't in decent shape, I just replaced all that stuff too on my MB5. I got the carb, cylinder, head, muffler, everything but the airbox.

You can use a kit with the stock exhaust, just expect minimal gains.

If you go for a kit... at the least, get the US carb and a 92 jet... You can find the jets at lawnmower shops and things of the like... the carb was common on a lot of Honda items.

I weigh 225 and my MB5 gets me going 55... After I drop the 6 speed in I'm sure she'll rev out to the moon... I'm gonna drop down to a 14tooth front sprocket here shortly (from the stock 16) see if that lets me hit 60. I have a couple good sized hills where I live, so i don't want to give too much torque away.

... pay no attention to the rear turn signal ground that decided to come off... :-) (edited)

Re: Honda MB5 Mods

Daniel, yeah I am positive - see that link I sent you in your previous thread about derestricting a UK mb5. you have to port the transfers, intake, exhaust ports, bigger carb, and open up a restrictor in the exhaust. they did all that to get it as fast as an American model.

and yes its all in good shape; email me if youre interested.

Re: Honda MB5 Mods

Thanks.

It Never gets old here to learn something

knew. And how to spend$ I don't have.😄

Re: Honda MB5 Mods

HPI, de-strict the stock pipe baffle, carbon reeds.

The stock pipe is way more fun all around than any of the aftermarket, unless you only care about top speed.

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