LCGB Forums

Warkton Tornado No.1 wrote:I’m pleased you seem to have got to the root of the problem but I guess it has been @ considerable cost in time & money

attachment=0]Keensert.JPG[/attachment]

Cost nothing but my time, and as I only do this as a hobby, I almost welcome problems and the challenges they present. Or let me put it another way; there is not the smallest chance that I would ever buy a lambretta that didn't need a lot of work.

Interesting what you say about zinc content.

dickie wrote:
Cost nothing but my time, and as I only do this as a hobby, I almost welcome problems and the challenges they present. Or let me put it another way; there is not the smallest chance that I would ever buy a lambretta that didn't need a lot of work.

Interesting what you say about zinc content.

Amen

Top end sorted now, so I'm turning my attention to the gearbox. I decided to lighten the clutch sprocket for no reason other than I felt like it. It was 800g before I started and 750g after I'd finished; a much smaller reduction than I expected. The likelihood of it making any noticeable difference is negligible but so what?

First I drew up a template for the centre on autocad and centre punched for some 20mm holes.
DSC_0475_zps1rrrcuqb (1) by richardhenderson1968, on Flickr

Then I cut them out with a 20mm holesaw
DSC_0477_zpssgr4dmed by richardhenderson1968, on Flickr

I should have made some templates for the edges but I did them by eye. Unfortunately they're (unsurprisingly) not as good as the centre but it's of no real consequence.
DSC_0478_zps6etrjjce by richardhenderson1968, on Flickr

It isn't the dead weight that matters, it's the reduction in the rotating mass that matters and the 50grams will have more effect that you might think

I did a rough 'back of an envelope' calculation and I reckon I've reduced the inertia by around 10%. Definitely worth it if you're going sprinting or building a peaky motor like an ss225 or rb but I'm not sure it's so significant on this set up. Still, every little helps.

Every little bit does help, a little bit here a little tweak there all adds to the final result.

I should have made some templates for the edges but I did them by eye. Unfortunately they're (unsurprisingly) not as good as the centre but it's of no real consequence.

You are spot on to be un-concerned for now. I applaud the idea of using CAD to make a template & wondered why you went ‘freehand’ on the sides.

However, if not now, perhaps @ a later date, you can do more work on the sprocket.

You can print on self adhesive transparent then apply as ‘stickers’ to an oil-free surface to get consistent results. For instance, those sides could be modified to oval or kidney shaped slots. Loads of you on here like your ‘Dremels’ but one of my favourite non-bedroom tools is my Makita die grinder. Less than a kilogram in weight, 25 000rpm & you can use proper sanding drums that make porting so much easier.

If anyone wants a pdf or dwg copy of the template, pm me. It has the edge templates on now too

Little bit more progress.

Elemec flywheel, but I've drilled out the rivets and replaced then with 10.9 button heads (M6 x 16 are the perfect length).

DSC_0562_zpsthz6qus5 by richardhenderson1968, on Flickr
DSC_0563_zps1t7v8jsu (1) by richardhenderson1968, on Flickr


Top tip: cover all the magnets in masking tape otherwise it's a nightmare getting all the swarf and filings off them.


That was nice and easy but I now have a problem. The kickstart spring is digging into the casing and I don't understand why. It was obviously doing this in its former life as the witness marks on the casing show.

Any ideas?
DSC_0569_zpsyizxem4c by richardhenderson1968, on Flickr

In wrong way round?

jonno wrote:In wrong way round?

Not according to sticky's. It did cross my mind to flip it over but the I think the tangs are different lengths.

OK, I've tried putting the spring in upside down and it's worse. This is a Spanish series 3 li side case with an Italian s3 li Kickstart shafts. I have no idea how to sort this other than buying different springs from different sources. I have 2 scootopia ones and they're both the same.

Someone must have seen this before?

Always a bit of a mark on the ones Ive done,but not that bad.Perhaps try an SIL from Scooter Restorations ,they may have Spanish ones .

There was something about this quite recently. They had the exact same problem with the kick start spring. I think it probably was on here. So worth searching. From what I can remember the tang on the spring was too long preventing it seating properly. Unless I imagined it all, which is possible.

ToBoldlyGo wrote:There was something about this quite recently. They had the exact same problem with the kick start spring. I think it probably was on here. So worth searching. From what I can remember the tang on the spring was too long preventing it seating properly. Unless I imagined it all, which is possible.

Here you go

viewtopic.php?f=10&t=6083&p=50842&hilit=Kickstart+spring#p50842

That's the one Toddy. I was sort of right.

Thanks gents. I've sort of fixed it by using a different spring from eBay, the one on the left. The one on the right is the scootopia one.
DSC_0574_zps9v9qlxcb (1) by richardhenderson1968, on Flickr

It isn't pretty though
DSC_0575_zpshe2y9hiw (1) by richardhenderson1968, on Flickr

By coincidence I had the sidecasing off my series 3 tonight as well. Much nicer and it makes me question if sticky's is correct. This one has its original spring with an Indian kickstart shaft of unknown origin.
DSC_0573_zpss4r2cqsg by richardhenderson1968, on Flickr

And so endeth the slowest engine build in history. Good job it's only got one cylinder!
DSC_0785_zpsut70snix by richardhenderson1968, on Flickr
I've got a couple of weeks off work after a manic 6 months so I'll get the chassis and bodywork stripped and off to Shaun Burns for some beating, blasting, welding and painting.

Looks a very good job there Dickie, more so considering the state of the original internals

dickie wrote:And so endeth the slowest engine build in history. Good job it's only got one cylinder!



I've got a couple of weeks off work after a manic 6 months so I'll get the chassis and bodywork stripped and off to Shaun Burns for some beating, blasting, welding and painting.

Any update on this one? Also when you swapped the rivets for cap heads on the flywheel, what did you use to secure them? Nylocks or std nuts, lockwashers and threadlock?