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6th gear why???

PostPosted: Thu Jun 25, 2009 1:20 am
by robert mack
whats the point in having 6th gear on the rt 125?
i can be pootling along at 55 in 5th, bang it in to 6th n the bike dies on me,i can watch the needle slowly going down to 40mph. its useless!!!

Re: 6th gear why???

PostPosted: Thu Jun 25, 2009 4:37 am
by DAVID THOMPSON
take the stuff from under the seat around the air box out i had a shop rag in there an mine could not get air
no storage under seat except at rear
it should go at least 65 mph in 6th
dave
also carb may be starving for fuel

Re: 6th gear why???

PostPosted: Thu Jun 25, 2009 9:10 pm
by DAVID THOMPSON
how many miles on the motor mine was slow till it had 3500 plus on it and then started to loose power
after it had 18,000 on it mine is stock front sprocket and a 52 tooth sx rear and runs 69 flat out at red line
but most of my area is 60mph or less so goes great
adaptor is made from old sprocket so sx fits
spacer details on request

also is fuel flowing from tank to carb ok with correct float adjustment
no dragging brake pads
and i use shell Rotella t in 10w 40
dave

Re: 6th gear why???

PostPosted: Fri Jun 26, 2009 4:51 am
by robert mack
hi dave

motor has just over 10,000 miles on it, dont know about sprockets though but will be changing them next month. float height is ok but i turned up the idle screw yesterday and is now a bit quicker. i use valvoline 10w40.

Re: 6th gear why???

PostPosted: Fri Jun 26, 2009 8:16 am
by Jamie
Its not that carb playing up again?

My SM will do 70mph, at 17000 miles.
Just had new sprockets and chain.

Jamie

Re: 6th gear why???

PostPosted: Fri Jun 26, 2009 6:52 pm
by robert mack
hi jamie

no mate. it just feels as if there is no ooomph in the zed. thinkin o new sprockets next month lol. when did you get the sm??

Re: 6th gear why???

PostPosted: Sat Jun 27, 2009 4:13 pm
by Jamie
Got the SM in April, bought a junker RT in May as a donor to the SM.
All working fine now.

Re: 6th gear why???

PostPosted: Sun Jul 12, 2009 9:01 am
by robert mack
hi

changed the rear sprocket from 49 to 52 teeth and new chain. used an sm sprocket with spacer,can hit 60/65 no probs now 8)

Re: 6th gear why???

PostPosted: Thu Nov 25, 2010 9:55 am
by tails
hi, do you know if the mz skorpion front sprockets fit the rt 125's??? i can get a set cheap but am not sure, is the spline in the gear shaft the same size as the rt???? if you can help, that would be great. thanks. tails. tails8888@hotmail.com also, thanks 4 the previous help!!! :-)

Re: 6th gear why???

PostPosted: Thu Nov 25, 2010 12:05 pm
by DAVID THOMPSON
the 125cc sprockets are different than the 660 y or the 500 rotax
dave

supplier in usa and details of mounting 52 tooth sprocket on rt125 on request
email add below or pm here on site

edit
Esjot USA
3550 N Union Drive
Olney, Il. 62450
USA
Tel. 618 393 2955
Fax. 618 393 2956


done some hunting and this is what i found
Front Sprocket:
50-15019-16
Rear Sprocket:
50-15051-52
this is for the sx125cc
the rt with this will do 69mph flat out at the rev limit
need to use the old 49 tooth sprocket to make an adapter for the offset at the wheel
Dave

Re: 6th gear why???

PostPosted: Tue Jun 28, 2011 4:00 pm
by gavman
Here in the UK 125cc are restricted so they can be ridden on a license without taking a full bike test. that might be why 6th seems to have no guts. my rt125 suffers the same problem but im told these restrictors can be removed but check your insurance will still be valid. 8)

Re: 6th gear why???

PostPosted: Tue Jun 28, 2011 8:31 pm
by DAVID THOMPSON
i do not think the uk bikes are restricted ...
biggest problem with a 125 cc 4 stroke
is everyone rings its NECK for more than it HAS TO GIVE

if its less than 400cc and 4 cycle expect it to be under powered
if its over 400cc and has power expect it to be a GAS HOG
dave

bike need at least 30 kw and weigh less than 150 kilo or 330 lb
to have and git up and go

the old bmw r69s was i think 42 hp and over weight and ran nice just took forever
to get to 100 kph

Re: 6th gear why???

PostPosted: Fri Jul 01, 2011 3:30 pm
by JayJay
The MZ 125's are NOT restricted in the UK, they kick out 11KW (the max for riding on CBT) which is what they should do in normall form, the only restricted ones are German IIRC