No Leaks and hub troubles

Time to do a final leak-down test. Most club toolkits have professional leak-down kits. I made my own several years ago from a blood pressure gauge and bungs from a homebrew shop, based upon an article written by Sticky for Scootering. There's no loss of pressure at all at 120 thingamy bobs. At 200 it holds for a good 30 seconds before the bung attached to the pressure gauge gets blown out. That's good enough for me. Note, leak-down testing should be done with the piston at bottom dead centre.

Steve supplied some new hub studs to replace the too long ones I tried to fit before. These are the perfect size. The CASA Octopus hub has eight holes. I need to use the "standard" ones which don't have a recess. I debate with myself whether to use any stud-lock. These studs can be hard to remove, but then again I'll be torqueing the nuts on properly and so shouldn't ever strip them, plus they have decent depth and perfectly sized 12mm heads on them. Right, a small dab of stud-lock it is then, to stop the studs getting unwound instead of the wheel nuts when changing tyres...

I bought new shoes to go with the new hub. It's interesting to see how these Scootopia shoes have the steel bit built in, rather than separate. Achieves the same end result...The size difference is just an optical illusion by the way.

Time to fit the chain-casing. Well, so I thought. I put it on with 4 nuts and then, following the AF instructions, I want to turn the wheel to see if the kickstart is ratcheting in first gear. I'm pretty sure it won't. Anyway, I decide to hold the hub on with it's nut, just so I can turn the engine over in first easily (sparkplug removed following the leak-down test). With the nut on the hub is totally locked! And this is with the shoes removed. I can't work out where it's locking, so use an engineers pen to white-out the casing. Hmm, there's the rub!

I try filing the area, but it doesn't make much difference. Looking at the hub I'm now not sure if the Indian casings are wrong or the CASA hub! Time to leave it so I don't fuck things up...Tomorrow I'll take the hub and shoes in to the brake specialist next to Motorini for skimming...Now it's time for a drink. This is turning in to a marathon build!

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Chaincasing assembly

Friday and Repco send a text to let me know that they have the ThreeBond in, so I collect it and fit the flange. Unfortunately, after a weekend away down the coast another leak-test fails! Off it all comes and back on it goes, using much more ThreeBond this time.

The instructions say to leave for 12 hours before leak testing, so time to pick up some other jobs. Double-checking the chain I decide it's too tight, so loosen it a bit. This time I also use a tab washer. Well them nuts are right in the gearbox...

The next job is to assemble the various kickstart piston components. 

Although this is a GP it has always had the seperate kickstart ramp, rather than the one built into the end-plate. Not sure if this was normal with later Indian engines or if AF insisted on it...I guess the ramp position based upon some marks that show where it was fitted before. At this stage I just loosely bolt it down in case it needs moving later. I'm using one of MB's Allen headed pins which I hold in place with some low strength thread-lock. A simple trick from Sticky's manual is to hold the kickstart shaft in a soft-faced vice and then turn the chaincase cover until the pin can be fitted after pushing the piston down.

Now to fit the external rubber stop and kickstart. I'm fitting this Series 3 engine in to a Series 2, to start with anyway, so have bought a new kickstart that is designed to clear the Series 2 bodywork. The position on the splines/ramp is perfect.

I can now bolt the ramp down permanently. With the kickstart fitted I use the big vice as a third hand, and a mallet as a fourth hand to hold the kickstart down while I get to the two bolts that are normally covered by the ramp. The middle bolt was too short and hence got replaced by a Triumph one that I had lying around. If I could be bothered I'd replace the other two as well, the quality of these Triumph ones being noticeably better.

Now that the piston and ramp are fitted I can check that everything clears the AF 5-speed box okay. The AF instructions say to fit a gasket and then check if the chaincase cover sits flat. For a first check I figure that it's quick and easy to see if the cover sits flat without a gasket, which it does. Sweet. To be sure I use some blu-tak to see that the kickstart clears the kickstart teeth that are on first. I don't have plasticine as recommended by AF. 

My phone goes. It's my agent (pimp). Can I get a tailored resume to her today? Bum, bugger, but I need to go back to work. Anyway, I'll fit the clutch lever before heading in. Quick and easy job. Err. I have a pile of bits and no obvious way to put them together. This must be in Sticky's manual somewhere but buggered if I can find it. I dig out the old Lambretta manual, which has a picture that still bears no resemblance to the bits I have.

After hunting on the internet I find a video that shows exactly what I need to do, so nearly an hour later it's done. Flipping heck, I'd just assumed that would be a simple job.

I'll leave bolting the cover down until everything is leak-down tested...

Wet Build

The bits from Steve have arrived, and I discover that I need some exhaust studs. FFS. The ones fitted to the TS1 had the nuts sealed on so tight that the studs came out rather than the nuts coming undone. Those nuts were not coming off the studs...Anyway, I can't wait for another delivery from Steve so try the local fasteners. Nope, they don't carry M7 studs...Time to hunt the garage. Old barrels, old barrels, must have some old studs...Nicky's old Casa 185 kit has some perfect ones on it, so they get stolen and cleaned up. I also clean up the stud holes in the barrel.

A bit of a hunt and I find the TS1 exhaust stub for my JL3 exhaust and it gets fitted with a new gasket and copper sealant. These exhaust nuts are legendary for coming loose, so I fixed the studs in with stud lock, used spring washers, fixed the original style brass nuts on with medium strength thread-lock, and then added an extra nut on each side also held on with medium strength thread-lock. Hopefully job done.

I've never been a fan of the usual hose type rubber mounts so I'm trying one of MB's new flange type mounts. With the YPVS reed block and packing plate it looks like a lot of bits! All get sealed up with silicon sealant. I torque the Allen headed bolts to 5 foot pounds and use low strength thread-lock as well.

The next job is to fit the piston and barrel. I use silicon sealant at the base of the barrel as well. Once the piston is fitted the barrel is lubed with 2 stroke and eased on, which is relatively easy with the TS1 barrel and thin Meteor piston rings.

The Casa Blackline head uses wide spacers on the studs, which will get in the way of the TTO CHT pick-up that I want to use. It's a simple job to file one of them down to clear...

I've now fitted the thicker base gasket to hopefully raise the squish clearance. Checking the piston at BDC and the exhaust and transfer ports are all still aligned okay.

Head on and off to check the squish again and I'm rewarded with a near perfect result. Close to, but above 1mm, for maximum safe compression. Nice.

Does your first job always influence you? My first real job was at Rolls Royce. They developed Blue Hylomar to seal gas turbine engines. As a result I've always used it for cylinder heads. Never had a problem. Just spray it on, clean off the overspray with a cloth dampened with parts cleaner and bolt the bugger on (progressively tightening the nuts up to 17 foot pounds in a diagonal pattern of course). Not sure you can get it in Australia so who knows what I'll do when this can runs out.

A quick check on the MB website and he says to ensure you seal the inlet bolt with sealant to prevent leaks. Ah, better do that then. Let's not think about the damage that would be done if it ever came out as well 😳. It's got a Nylok nut with thread-lock on it...

After leaving everything overnight for the sealants to go off I give it a leak-down test. No surprise that the Viton flange is leaking like a sieve, which I'd expected not having used any sealant. I remember Nevil Cope asking on one of the Facebook groups about which sealant to use here, so I send him a message. Threebond 1104 is the answer. Repco carry it but they have to order it in. It'll be in store tomorrow.

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Dry Building

Someone on Facebook mentioned how we just used to build and ride scooters back in the Eighties. Yep, we did. And some were quick, some were slow, some ran forever, some constantly blew up. Personally, I wouldn't have known a squish from a pumpkin and jetting was guessed. I did set timing, using Rizla papers and trusting the existing marks...We now have access to decent manuals (thanks Sticky) and the two-edged tool below.

The Blackline piston is made by Meteor. Interestingly I remember these as a mid-range piston back in the eighties/nineties. Certainly not as good as an Asso or Jap one. How times change, Italy now being a supplier of quality rather than cheaper stuff...It uses the C circlips, which are good but a bastard to fit. Fortunately Casa came up with a tool to sell us that solves that problem. Erm, anyway, they do fit very tightly and should stay where they belong.

Small-end bearing lubed and piston fitted...The Jasil crank came with a quality small-end bearing, but this got pressed in to service as an emergency replacement for the one in Nicky's S1. Anyway, Steve supplied a decent quality one...

A quick check shows that the TDC is still good. It shouldn't have changed in theory but no harm in checking.

The next job is to check the squish clearance, which needs to be between 1mm and 1.5mmm. When doing a dry build the most accurate measurement is achieved by fixing some solder to the piston in two V shapes, in parallel to the gudgeon pin. Hold these on with some grease, torque down the head to 15 foot pounds and turn it over TDC. It'll be stiff at the top as it squashes the solder. Take the head off and measure the squashed bits with a Vernier gauge. A bit of a pain but definitely better than putting a single piece of solder down the spark-plug hole, which will probably give a higher reading (the piston being squashed to one side...). I'd always used the latter until reading about the former in Sticky's manual, which made more sense in my head. I'd still use the solder down the plug technique in preference to stripping a built top-end, but might be a bit concerned with a 1.1mm result...

I get a smallest measurement of 0.93mm and largest of 1.05mm. Dammit too small! I could possibly get away with this, but possibly getting away kind of defeats the point of a dry-build. I could fit a head gasket or use a fatter base gasket. I don't have a head gasket (and would probably struggle to get one thin enough) and prefer not to fit one with the Casa head. A hunt amongst my gaskets reveals a fat one, which I'm going to try. Unused it is 0.4mm thicker than the one that has been torqued down. I'm guessing this will mean 0.2mm to 0.3mm when fitted, which should be sweet. It needs trimming to match the larger TS1 transfers...

A fatter base gasket will move the barrel up relative to the piston and slightly move the exhaust/transfer port openings, but 0.2mm shouldn't matter. I'll check though...

Looking at the top of the TS1 barrel I can see that someone has tightened the head down so hard at some point that the head gasket has left a dint in the aluminium barrel! I want a perfect seal. Normal advice is to lap the head on some wet and dry taped to a piece of glass. Great assuming your barrel is flat, which is probably true with an iron barrel. I decide to lap the head and barrel together using grinding paste to match both parts. I used to do this all the time and chatting with others it seems I'm not the only one.

A sign of a good seal is when the paste sticks the head to the barrel 

The next job. Fit a TTO cylinder head temperature pick-up. Most Lambretta heads need some Dremel work to allow a TTO CHT gauge to be fitted. The Casa one is about the easiest I've ever done, just requiring a small bridge of metal to be removed. 

Next. I'm using a YPVS reed block, which requires a packing plate. These plates are manufactured specifically for this job, so you'd think they would be a perfect fit. Yeah, nah, a bit of filing is required.

The final job is to check the fit of the MB flange type TS1 manifold. This is a perfect fit. I'm replacing the mammoth 34mm carb with a more sensible 30mm one, hence the new manifold. It looks lovely as well!

I've gone about as far as I can with the top-end until the bits I've ordered from Steve arrive...so I turn my attention to the chaincase cover. The Indian kickstart bushes were very badly fitted.

Possibly not a problem for a standard motor, but the AF 5-speed box needs 1.5mm more clearance than a four speed, and that's over 1mm used right there...New Scootopia bushes are fitted simply by heating, tapping out, tapping in etc. 

The kickstart ramp holes are cleaned up with a tap, the bushes lubed with grease, the kickstart oil-seal is fitted,  and then the kickstart shaft.

The AF 5-speed instructions emphasis the importance of making sure the kickstart shaft is held as far in as possible, to maximise clearance to the new box. They say at least two shims are usually required. I fit 2 standard ones and a thin one to give a nice tight fit. Fitting a Readspeed style circlip with extra tabs, as advised by Sticky, is a must! Steve carries these in stock at Lambretta Obsessions.

At this point some complicated clearance checks are required in the AF instructions, and I'm buggered, so time to call it a day.

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