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Re: lambretta 290 rotax

PostPosted: Thu Dec 07, 2017 12:15 pm
by a-teamlambretta
well done , looks and sounds great . hope it goes well too .

Re: lambretta 290 rotax

PostPosted: Thu Dec 07, 2017 4:16 pm
by Digger
8-)

Re: lambretta 290 rotax

PostPosted: Thu Dec 07, 2017 5:01 pm
by Swat
Fantastic engineering again - hard to top the 350, but given this retains the std Frame & main casing, I think its genius...

Re: lambretta 290 rotax

PostPosted: Thu Dec 07, 2017 7:12 pm
by hullygully
Carmon Swatty.............. is it cos he's changed the tank? 8-)

Re: lambretta 290 rotax

PostPosted: Thu Dec 07, 2017 7:18 pm
by modster79
I’m going to miss this post, but great to hear it at last, well done mate.

Re: lambretta 290 rotax

PostPosted: Thu Dec 07, 2017 7:20 pm
by holty
thanks for the nice feedback, im just chasing a few coolant leaks at the moment, that many hoses and connections, started it today 3rd kick , which i was pleased with, might get out for a proper ride soon, it pulls like a train, its got a gt200 gearbox and a 17 front sprocket and it just whips through the gears easy as you like, no drag on the clutch, which has impressed me as i adapted it myself.

Re: lambretta 290 rotax

PostPosted: Thu Dec 07, 2017 7:44 pm
by Warkton Tornado No.1
Well done with all of your hard work!

It sounds a tad rich but fit on the video. Just right!

That's one 'home brew' that will take some topping.

I just knew that GT200 gearboxes would make a comeback one day! I'd doubt you'll get anything stronger & with that torque, would a five speeder serve any purpose? ;)

Re: lambretta 290 rotax

PostPosted: Thu Dec 07, 2017 11:12 pm
by holty
Warkton Tornado No.1 wrote:Well done with all of your hard work!

It sounds a tad rich but fit on the video. Just right!

That's one 'home brew' that will take some topping.

I just knew that GT200 gearboxes would make a comeback one day! I'd doubt you'll get anything stronger & with that torque, would a five speeder serve any purpose? ;)

thanks for the kind words, and the advise you have offered, plus the clutch spider, i understand what your saying about these gearboxes, only a torque monster can pull one.

Re: lambretta 290 rotax

PostPosted: Fri Dec 08, 2017 9:23 am
by coaster
Fantastic project and some very clever engineering, bloody well done. Re the gearbox, with that much torque, do you actually need 1st, 2nd and 3rd? ;)

Re: lambretta 290 rotax

PostPosted: Sat Dec 16, 2017 1:41 am
by Fast n Furious
I bet it needs deep pockets when buying petrol?
I pains me a bit to be paying 4 times what the Vespa GTS boys get away with.
That's the price of style though eh

Re: lambretta 290 rotax

PostPosted: Sat Jan 13, 2018 10:29 pm
by holty
just a little bit of an update, the other lammy in the states that has one of these barrels fitted was on the dyno and melted a piston, the opinion is that the cause was too small a stinger in the exhaust pipe, after a few calculations by a few people a 30mm stinger has been recomended so i have deceded that it might be a good idea to alter mine. i measured mine and it was about 26mm so i ordered some baffle tube and some 30 mm tube, heres a couple of pics.
first pic shows baffle tube welded to 30mm tube at each end.
ImageUntitled by stephen holt, on Flickr

its an nk end can by the way, next pic shows end can finished

ImageUntitled by stephen holt, on Flickr

and the last pic shows the new tube and can tacked on, i will be adding a bracket underneath, then welding it properly and adding a few supports

ImageUntitled by stephen holt, on Flickr

Re: lambretta 290 rotax

PostPosted: Sun Jan 14, 2018 10:47 am
by coaster
I had one of those end cans on a Supertourer that snapped at the point where the perforated pipe met the solid end pipe. It snapped due to fatigue at all the weld points. I think the pipe needs to be slightly compressed when it is assembled otherwise if play in the rivets occurs the pipe will be able to move. Maybe a support bracket will do the trick too.

Re: lambretta 290 rotax

PostPosted: Sun Jan 14, 2018 12:32 pm
by Scooterdude
I’d be inclined to weld in two pieces of steel rod opposite each other and running along the length of the perforated tube bunt at 90 degrees one end and welded to the inside of the cap end with the three bolts and the other end welded to the beginning part of the solid tube before it exits the end cap.

Re: lambretta 290 rotax

PostPosted: Sun Jan 14, 2018 5:53 pm
by holty
i welded a piece of steel tube to both ends of the baffle tube, it is then welded to the main flange on the inside where you cant see it, it is self supporting but the outer part is well riveted on as well, hopfully it will be ok.

Re: lambretta 290 rotax

PostPosted: Sun Jan 14, 2018 7:23 pm
by Andy B.L.C.
Have fun, you so deserve it... Much respect! :)

Re: lambretta 290 rotax

PostPosted: Wed Feb 21, 2018 7:15 pm
by holty
had a bit of a problem, i bent the kickstart shaft trying to kick it off, so i have purchased a casa shaft complete with piston from one of their new wide sidecasings , when fitted kickstart splines didnt line up correctly so i decided to install a ramp on the side case, had to slot the holes a bit, and remove some material from one end, but did the trick fine, i obviously had to remove the gearbox backplate and cut the ramp off, a worthwhile modification. this engine does have a real lot of compression so i decided to build a moto gp style roller starter to bump it off with when cold, i added a go kart engine to it instead of an electric motor as its cheaper and more powerful, will add some pics in a bit, gave it a good road test after getting it started with the roller starter and found that it had massive vibrations at about 50 mph in top gear, not ideal, anyway i decided to change the large engine mounting for an old one out of my rb250 and it did the trick, lovely and smooth now, not had it in the powerband yet, ive got to get some miles on it and get it run in before i get it on the dyno, runs very cool about 40 degrees so cooling system is working maybe too well, but very pleased upto now.
ImageUntitled by stephen holt, on Flickr
ImageUntitled by stephen holt, on Flickr
ImageUntitled by stephen holt, on Flickr
ImageUntitled by stephen holt, on Flickr
ImageUntitled by stephen holt, on Flickr
ImageUntitled by stephen holt, on Flickr
ImageUntitled by stephen holt, on Flickr

Re: lambretta 290 rotax

PostPosted: Wed Feb 21, 2018 9:13 pm
by bike grim
Bloody fantastic. Wish I had the patience and the know how.

Re: lambretta 290 rotax

PostPosted: Wed Feb 21, 2018 10:09 pm
by Solid Air
A great job there, I love how understated it looks. Loads of great work, the radiator grills don't give much away considering the amount that's been done, spot on! 8-)

Re: lambretta 290 rotax

PostPosted: Sat Mar 03, 2018 10:12 am
by holty
i took it out last saturday to get some more miles on it, i also knew some cold weather was on the way so it would be its last journey for a bit, did about 20 miles and ran sweet as and didnt miss a beat. i have noticed that the rh side of the scoot is covered in oil from the stand off coming out of the carb, so i think i will be making a bell mouth to attach to the 34 dellorto and i will have to cut a hole in the side panel to allow it through, this will keep the oil off the inside of my panel and allow the engine to suck it in, the rotax engine that the barrel came off didnt have reedvalve induction it had discvalve and i suspect thats why the reed is struggling to keep all the induction charge inside the case, its not a big issue but just a little thing to address, roll on warmer weather so i can get some more miles done,
holty

ImageUntitled by stephen holt, on Flickr

Re: lambretta 290 rotax

PostPosted: Sun Mar 04, 2018 4:15 pm
by Fast n Furious
Very tidy.
Good luck Stephen. :D