Page 5 of 8

Re: lambretta 290 rotax

PostPosted: Thu Sep 07, 2017 3:53 pm
by holty
clutch basket with cush drive has been extended, i will have to cut it down to size, i will have to get the plates in there to see how many i can squeeze in, does anyone know whats the strongest springs please ?
ImageUntitled by stephen holt, on Flickr

Re: lambretta 290 rotax

PostPosted: Thu Sep 07, 2017 4:56 pm
by jonno
Camlam race springs are very strong ,tho youll end up with a left arm like Popeye lol

Re: lambretta 290 rotax

PostPosted: Thu Sep 07, 2017 5:55 pm
by hullygully
I think the Broady strong uns are 2.3mm thk!!!! toooooo strong for 4 reedspeed red plates with bell machined out for 5, scoot crept :(

Re: lambretta 290 rotax

PostPosted: Thu Sep 07, 2017 9:43 pm
by a.lo
I thought that with the large amount of plates you could fit in that basket, you could actually run softer springs, at least not very strong ones.

Re: lambretta 290 rotax

PostPosted: Sat Sep 09, 2017 9:35 am
by holty
a.lo wrote:I thought that with the large amount of plates you could fit in that basket, you could actually run softer springs, at least not very strong ones.


this basket has a cush drive fitted so it doesnt have has much depth available as a standard basket, so i have gone for a packer plate and an extended spider and basket to enable more plates than a standard basket, mainly as im hoping for a very high amount of power and torque, so its going to have to be strong, thats why i think it will need strong springs, i would prefer soft but cant see them holding the power this is going to make, it will probably end up being a bit of trial and error to see what will prevent clutch slip.

Re: lambretta 290 rotax

PostPosted: Fri Sep 15, 2017 4:48 pm
by holty
made a bracket for my fuel tank, and then a tray for the battery, my external pick up arrived, so thats my next job
ImageUntitled by stephen holt, on Flickr
ImageUntitled by stephen holt, on Flickr
ImageUntitled by stephen holt, on Flickr

Re: lambretta 290 rotax

PostPosted: Sun Sep 17, 2017 9:42 am
by holty
got my external pick-up fitted, i bit tricky as when i lighten the flywheel i removed the arrow, anyway i just used a dial gauge to find tdc then put a hacksaw cut it the flywheel and marked the mag housing for tdc, then used my timing wheel to mark 17 degrees before tdc, then i was able to drill and tap the flywheel for the trigger, i needed to use the large one, you get both small and large in the kit, i used plenty of studlock on the holding screw for the trigger so cannot come undone. i also assembled my clutch so was able to cut the basket down to a size that matches the extended spider, it might want a bit more filing off. i also had a bit of a tight spot in the gearbox so i had that apart, turned out that one of the gear selector pawls was too tight in the cursor track, replaced th pawl with another and gearbox nice and smooth, so got that shimmed up and bolted up and finished, i have found another problem, the rear brake cam and shaft is very sloppy in the hole in the casing so i think i will need to ream out the hole and make a bush to fit.
ImageUntitled by stephen holt, on Flickr

Re: lambretta 290 rotax

PostPosted: Mon Sep 18, 2017 9:28 am
by Knowledge
I'm still loving this story. It is good to see you putting almost as much effort into keeping us informed as you are putting into the build.

Re: lambretta 290 rotax

PostPosted: Tue Sep 19, 2017 3:08 am
by Mr G in NYC
Great Thread , well done . G

Re: lambretta 290 rotax

PostPosted: Tue Sep 19, 2017 8:19 pm
by coaster
hullygully wrote:it's just like waiting for the next series of Game Of Thrones this....... :lol:


Or Better Call Holty 8-)

Re: lambretta 290 rotax

PostPosted: Tue Sep 19, 2017 9:36 pm
by holty
thanks guys, its nice to get a bit of feedback, ive reamed out the rear brake spindle hole and added 2 oilite bushes, it was quite a tight fit so warmed the casing up and made a drift to knock them in, well pleased with the end result, a perfect fit.
ImageUntitled by stephen holt, on Flickr

Re: lambretta 290 rotax

PostPosted: Tue Sep 19, 2017 10:30 pm
by Adam_Winstone
Nicely done!

Re: lambretta 290 rotax

PostPosted: Thu Sep 21, 2017 5:30 pm
by hullygully
Would the exposed position of the pick up, lower end of engine/mag flange, be in more of a chance of water contact? :?
Or has some one being using one in all weathers?
Would water have any detrimental effect on the spark? (only asking cos its a geat idea this) 8-)

Re: lambretta 290 rotax

PostPosted: Thu Sep 21, 2017 7:10 pm
by dickie
hullygully wrote:Would the exposed position of the pick up, lower end of engine/mag flange, be in more of a chance of water contact? :?
Or has some one being using one in all weathers?
Would water have any detrimental effect on the spark? (only asking cos its a geat idea this) 8-)


If the components are well sealed (and they seem to be on mine) then they'll be fine. There is no spark in that area, just a magnetic field, and water has (almost) no effect on that. The external pick up is nice when you're adjusting it, but has diddly squat to do with performance once you've set it up.

Nice motor by the way.

Re: lambretta 290 rotax

PostPosted: Fri Sep 22, 2017 10:06 pm
by holty
ive welded an extension to the kickstart and enlarged the slot for the pin, polished the side case and fitted the kickstart and shaft, first spring didnt work right so had to strip and try another, works very well, i got an sx kickstart as they are a little longer as i think it might be hard to kick.
ImageUntitled by stephen holt, on Flickr
ImageUntitled by stephen holt, on Flickr

Re: lambretta 290 rotax

PostPosted: Sat Sep 23, 2017 8:25 am
by coaster
Amazing engineering Holty but just wondering with the additional compression plus extending the shaft whether the shaft would benefit from some beefing up on the diagonal section?

Re: lambretta 290 rotax

PostPosted: Sat Sep 23, 2017 8:40 am
by coaster
hullygully wrote:Would the exposed position of the pick up, lower end of engine/mag flange, be in more of a chance of water contact? :?
Or has some one being using one in all weathers?
Would water have any detrimental effect on the spark? (only asking cos its a geat idea this) 8-)


The pickup is completely sealed and goes inside the cowling on fan cooled engines. Anthony Tambs (Scootronics) who makes and sells them has posted oscilloscope videos which show a rock steady pulse as apposed to a wandering pulse from the conventional pickup. Won't make it more powerful but might improve tickover and starting. The real beauty of the external pickup is that you can leave the internal one in place in case the other one fails ;)

He has just taken someone on to help with assembly of his electronic gizmos which is not before time as his waiting list is getting silly :cry:

Re: lambretta 290 rotax

PostPosted: Sun Sep 24, 2017 9:55 am
by holty
coaster wrote:Amazing engineering Holty but just wondering with the additional compression plus extending the shaft whether the shaft would benefit from some beefing up on the diagonal section?

i did think about it, i have a shaft that has bent and half sheared, it an original innocenti one and i dont think any welding would stop it from breaking where it did, i will say the one i have used does appear to be quite beefy and rayspeed who i bought it from said they have had no problems with them, so fingers crossed.

Re: lambretta 290 rotax

PostPosted: Fri Oct 06, 2017 9:30 pm
by holty
have had a re think and moved my tank forward to give more room for the carb

ImageUntitled by stephen holt, on Flickr

ive also added an extra bracket to my exhaust to give more support

ImageUntitled by stephen holt, on Flickr

and ive just fitted my new front sprocket, chain, 7 bgm race clutch plates and mb springs

ImageUntitled by stephen holt, on Flickr

Re: lambretta 290 rotax

PostPosted: Sat Oct 21, 2017 6:28 pm
by holty
so engine is all finished now, so i have taken the engine out of my old rb250 as this is where the 290 is going, o also removed the long range tank as it left no room for the carb, and fitted the 13 litre tank in the forward position, also done a repair in the area behind the number plate, been to rayspeed today and got the rest of the parts i need, apart from the bits ive forgot :D
ImageUntitled by stephen holt, on Flickr
ImageUntitled by stephen holt, on Flickr
ImageUntitled by stephen holt, on Flickr