Just thought id say recently purchased a '86 MT5 off eBay locally! As i was 16 a fair few months ago thought i may aswell get my CBT and Insurance sorted for it! here some piccies of her, needs a tad attention.
It has NGK SP new bits n bobs rear tail light, ignition, headlight lens and bulbs all round.
only £155
just wondering if anyone ever had one bk in the 80's/90's my dad did so i got a few plans for de-restriction in mind - Carb opening up, bigger main jets to balanace air intake. Its had a new exhuast also due to its not a honda stock one. I may plan on changining the gearing on the front and rear for more road use

comments!

gav!

oh and aftr about 30mins of mastering the clutch control

god that bikes crap












gav, that was a joke mate

im on study leave! :yum:
need a job! im thinking £2000 by January for Uno insurance, and everyfin for this bike!
my quote for this is 279 with bennets cheap thn the others ive had

not seen you round wootton...STILL lol

unonumero said:

not seen you round wootton...STILL lol

Click to expand...

you was in marston mate!! i been drivin past most days.

neways you know im gonna give you a lift down the cruise so you see me then

3 weeks mate

i was at my mates house last night, he has a 1.6 Vitara in a massive filed= 4wd proper drifting, burnouts and power slides haha was so fun. His little bros have cars like novas, fiesta, fourtrak and sj410 nice collection of MoT failures lol

I didn't have an MT5, but I did have an H100A between 1986 and 1988. That used a bigger (99cc) version) of the engine you have fitted to your bike, producing around 11bhp and good for 65mph (wow!) I rode (read 'thrashed') my Honda everywhere for two years and loved it. It was one of the vehicles I most regretted selling

To be honest you're wasting your time tuning the 49cc engine. The 99cc H100 engine is a straight swap and will give you more power and torque than you can get from 49cc. I doubt if you will find one, but there were also 80cc big bore kits available for mopeds like the MT5. Keep an eye on Ebay as you never know your luck. Then again, H100 engines crop up fairly often so I'd suggest going down that route. Make sure you get the carb with it as well

If you must tune the 49cc engine, then you are restricted to raising the exhaust port height, slightly up-sizing the jetting and trying to find an expansion chamber exhaust. They weren't really restricted as such and didn't have the option of powervalves. If you tune it you'll also make the engine much more peaky in its power delivery, and it wasn't exactly tractable in the first place.

Fit an H100 engine - it makes far more sense

thought of it already but once that goes in its no longer legal for me on the road !
so im just thinkin to tune MT
the US versions of the MT have 3mm bigger carb on and the main jet is larger.
i've seen a fair few h100 engines on eBay but not really got the money to swap and i wont be legal on it
gav

unonumero said:

thought of it already but once that goes in its no longer legal for me on the road !
so im just thinkin to tune MT
the US versions of the MT have 3mm bigger carb on and the main jet is larger.
i've seen a fair few h100 engines on eBay but not really got the money to swap and i wont be legal on it
gav

Click to expand...

If you tune your engine to go more than 33mph whilst it's registered as a moped and you're 16 years old it won't be legal either.

Jetting alone won't raise the power. You need to have the exhaust port raised and a more suitable expansion chamber exhaust fitted. The price it will cost to buy those and have the work done on the engine will most probably cost more than buying an H100 engine in the first place.

I've been there and done it, learnt from my mistakes and realised it's nearly always better to swap in a bigger version of the engine than to tune the existing one.

unonumero said:

oh and aftr about 30mins of mastering the clutch control

Click to expand...

Gav, without sounding like your dad for Gods sake don't ride your bike without protective clothing and a crash helmet - even if it's off road. I've got friends who have ugly skin grafts on their body and even bone grafts in their skulls after they fell off at low speeds whilst not wearing protective gear. Not to mention those with metal pins holding their limbs together. Most of the skin grafts and head injuries could have been prevented or at least lessed in severity had they been wearing proper safety gear.

You only get one body, so look after it

i know my dad broke his leg, my uncle broke his arm, leg and buggered his ankle and my other uncle is in a wheel chair due to it so i think im taking extra precautions i have my AGV helmet sorted need to order some spares for it from customlids.co.uk
my dad will make me wear that gear anyway he has a 125 and fireblade. i didnt wear helmet the other day becuase i was mainly gettin used to the bike and clutch control...as i only jus learnt to ride manual bikes!

you wouldnt happen to be interested in a haynes manual for it?

I just happen to have one :chin:

yeah sure! i was watching one on eBay
jus message me
thanks gav

ooh just noticed... lol your in nz im uk =[
im not too keen on international shipping

nope, in not, im FROM NZ

im up near London

At least he didn't say you lived in Jamaica

Stuart DemonD said:

At least he didn't say you lived in Jamaica

Click to expand...

I thought when you wrote that, but then realised what you were getting at

'Just need some Reggae Reggae sauce'

i remember the mt5 well, i used to go out with a girl with an MB5 (road version)when I was doing my A levels. The engines are very heavily restricted, seem to recall 'mechanics and the biker' (magazine evolved into performance bikes magazine in 1985), or it may just have been called 'mechanics' then did a full on tuneup of the mb5 engine. seeem to remember main restriction was very mild porting on them, cant remember about the card, there may have been a collar in the exhaust. I can remember however that on the inlet side, there were ribs cast on the barrel to prevent you opening the reed valve stops past 5mm........ have a look on ebay for bike magazines of the early 80's, theres a slim chance you may find the issues, sadly i car booted mine about 8 years ago. To derestrict a Uk model is a lot of work, but im sure they got the mb5 upto around 65 mph.

Remember the H100 well too, very nearly had one, but bought a 2nd hand s reg yam RS100 instead, no airbox, micron, managed to get it just off the clock (a whole 80 mph, my old cavalier V6 did nearly that in second gear )

Good luck, and use decent 2 stroke oil, I ber belray Si7 and castrol A545 are things of the past now.........

serin said:

nope, in not, im FROM NZ

im up near London

Click to expand...

oh in that case yeah im interested
i need a job though, i owe my dad for the bike and some parts, need to sort out my CBT, insurance, MoT and Tax!

johnstoke said:

i remember the mt5 well, i used to go out with a girl with an MB5 (road version)when I was doing my A levels. The engines are very heavily restricted, seem to recall 'mechanics and the biker' (magazine evolved into performance bikes magazine in 1985), or it may just have been called 'mechanics' then did a full on tuneup of the mb5 engine. seeem to remember main restriction was very mild porting on them, cant remember about the card, there may have been a collar in the exhaust. I can remember however that on the inlet side, there were ribs cast on the barrel to prevent you opening the reed valve stops past 5mm........ have a look on ebay for bike magazines of the early 80's, theres a slim chance you may find the issues, sadly i car booted mine about 8 years ago. To derestrict a Uk model is a lot of work, but im sure they got the mb5 upto around 65 mph.

Remember the H100 well too, very nearly had one, but bought a 2nd hand s reg yam RS100 instead, no airbox, micron, managed to get it just off the clock (a whole 80 mph, my old cavalier V6 did nearly that in second gear )

Good luck, and use decent 2 stroke oil, I ber belray Si7 and castrol A545 are things of the past now.........

Click to expand...

haha sweet! yeah, we found a website that has some clips from it, my dad used to use that magazine when he brought his mt5 brand new back in the day
amazing he still remembers some of it lol i would have forgotten!
my mates have rs50s, DNAs and a Derbi Senda!

havent read the threads so sorry if this has been said already, but on the MT5 the ignition dies at approx 6500-7000rpm (iirc) due to a restriction in the CDI unit. you can buy derestricted CDI units, well you could once upon a time, i dont know if you still can. thats the main thing to do on an MT5.

another problem with the MT5 is the speed at which the exhaust gets blocked up inside. you need to take it off and soak it in acid or petrol or whetever you think is best to dissolve all the crap. you need to do this fairly regularly to keep it running well. i remember there was a mod you could do to the exhaust if you chopped it open to stop this happening as quickly, and to give more power. iirc there is a narrowing part inside near the front of the exhaust, which you can grind off and then weld it back together. if you have an aftermarket exhaust i would guess this isnt neccessary.

if you get a derestricted CDI, clean/mod the exhaust, rejet the carb (only next size up on main unless you make major changes), fit an airfilter, then if you're lucky it will keep up with a DT50

i woudnt change the sprocket sizes unless you get a derestrcited CDI unit. if you do derestrict it, get a back sprocket with 1 less tooth, it makes a big difference.