Pit bike engine

Anything related to Lambretta or Vespa Scooters fitted with LC, Motorcycle and/or Auto engines! Ask technical questions, post helpful information, pictures, or just read and learn.
ducksta
registered user
Posts: 1520
Joined: Sat Nov 20, 2010 10:16 pm
ebay user ID: joggersnipple
Main scooter: t5 classic 172 mallosi
Location: york
x 4
Contact:

Pit bike engine

Postby ducksta » Thu Apr 20, 2017 11:45 pm

Hi guys will I get a pit bike engine to fit in a vespa frame, I usualy take the arse end off the vespa and make a cradle but not done one with a swing arm and what wheel would I use any ideas appreciated
0 x
live life your a long time dead

Ginch
registered user
Posts: 119
Joined: Fri Jan 03, 2014 9:20 am
Main scooter: Vespa 150 Super
x 1
Contact:

Re: Pit bike engine

Postby Ginch » Sat Apr 29, 2017 3:17 am

Love the idea... but the room available and the length of a pit bike motor might be difficult to resolve. The 177 on my bench at the moment is about 420mm long (swingarm to shock mount) not including the exhaust.
Image

These motors are approx. 280 wide, which means if you leave the wheel in it's original position and place the motor alongside, then the motor ends up around 80mm or so further out to the right.
You can't hang a wheel off the output shaft as they're not designed to carry the weight, so the cradle would also need to carry a rear axle that the wheel attaches to.

A modern motorcross engine design is higher than it is long, this might allow your wheel to run directly behind the motor on a short chain (again on some kind of cradle.
This KTM 65cc (as far as I can find out) is about 13hp, dimensions 250 x 250 x 205mm (soruce Alibaba!). It looked like the 205 was the length dimension.

Image

Image
0 x

ducksta
registered user
Posts: 1520
Joined: Sat Nov 20, 2010 10:16 pm
ebay user ID: joggersnipple
Main scooter: t5 classic 172 mallosi
Location: york
x 4
Contact:

Re: Pit bike engine

Postby ducksta » Sat Apr 29, 2017 8:09 pm

Cheers food for thought.
0 x
live life your a long time dead

holty
registered user
Posts: 571
Joined: Wed Jul 15, 2015 11:52 pm
ebay user ID: amholt123
Main scooter: lambretta gp
Location: east yorkshire
x 19
Contact:

Re: Pit bike engine

Postby holty » Sat Apr 29, 2017 8:51 pm

i like this set up, makes chain alignment easier and saves space, im sure it will handle better, short swing arms are usually a very hard rideImage
Image
0 x

ducksta
registered user
Posts: 1520
Joined: Sat Nov 20, 2010 10:16 pm
ebay user ID: joggersnipple
Main scooter: t5 classic 172 mallosi
Location: york
x 4
Contact:

Re: Pit bike engine

Postby ducksta » Sat Apr 29, 2017 9:36 pm

That looks spot on what engine and rear wheel is it.
0 x
live life your a long time dead

holty
registered user
Posts: 571
Joined: Wed Jul 15, 2015 11:52 pm
ebay user ID: amholt123
Main scooter: lambretta gp
Location: east yorkshire
x 19
Contact:

Re: Pit bike engine

Postby holty » Sat Apr 29, 2017 10:21 pm

the engine is a rotax max go-kart engine, the chain and sprockets are kart as well, its in a smallframe so very light, i think its good for 100mph, rear wheel is a typhoon i think, it was made by frank sanderson at lambretta innovations, if you look on his website you will find more pics and info.
0 x

holty
registered user
Posts: 571
Joined: Wed Jul 15, 2015 11:52 pm
ebay user ID: amholt123
Main scooter: lambretta gp
Location: east yorkshire
x 19
Contact:

Re: Pit bike engine

Postby holty » Sat Apr 29, 2017 11:02 pm

i used a yamaha bws wheel, i used the original disc fitting 4 holes to mount an adaptor for rear sprocket, and i had the other side turned down in a lathe to make a flat area for a brake disc mounting.its 10 inch by the way.Image
Image
Image
0 x

Ginch
registered user
Posts: 119
Joined: Fri Jan 03, 2014 9:20 am
Main scooter: Vespa 150 Super
x 1
Contact:

Re: Pit bike engine

Postby Ginch » Sun Apr 30, 2017 1:47 pm

holty wrote:i like this set up, makes chain alignment easier and saves space, im sure it will handle better, short swing arms are usually a very hard ride


That belongs to somebody here doesn't it? OzOAP I think...from memory it only has the one gear so I don't know how that would affect the rideability of it? But looks like it's a good fit! I guess no gearbox makes it a short engine!

Just found this -
OzOAP
unregistered user > > Mar-26-05, 06:08 AM (EDT)
17. "Its mine!!"
In response to message #16
The radiator is a Rotax rad. For peak performance the engine should run between 45 and 60 deg. Anything over 80 and it can get expensive. (sorry, more expensive!!). Ive put the rad on front for max airflow.
Its a single speed with a centrifugal clutch that engages at about 3000 rpm, so the faster the crank goes (14500) the faster the back wheel goes!!
Ive got a few sprockets to try to sort gearing for sprints, rideouts, rallys, ect.
0 x

holty
registered user
Posts: 571
Joined: Wed Jul 15, 2015 11:52 pm
ebay user ID: amholt123
Main scooter: lambretta gp
Location: east yorkshire
x 19
Contact:

Re: Pit bike engine

Postby holty » Sun Apr 30, 2017 6:45 pm

well found, send ozoap a pm he might be able to give you more info, i have seen another rotax engined scooter, this was a geared 125, i belive aprillia, that was fitted to a lambretta using the same idea with a long arm, with engine on top, with would be pefect for a largeframe vespa
0 x

ducksta
registered user
Posts: 1520
Joined: Sat Nov 20, 2010 10:16 pm
ebay user ID: joggersnipple
Main scooter: t5 classic 172 mallosi
Location: york
x 4
Contact:

Re: Pit bike engine

Postby ducksta » Tue May 02, 2017 4:32 pm

Cheers
0 x
live life your a long time dead


Return to “Liquid Cooled, Motorcycle Engine & Automatics Section”

Who is online

Users browsing this forum: No registered users and 1 guest