JB Fabrication Lambretta Engine Test Stand

This is the Lambretta Engine Test Bed made by Jon Betts at JB Fabrication.

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The frame is painted black and comes in three parts, which fit together with the four supplied nuts, bolts and washers. You also get a bottle for the fuel supply which has an on/off tap and hose included that sits in a holder on the frame.

The welding is very neat and the metal is more than strong enough to hold a Lambretta engine.

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If you have a spare headset that you’re not using, the raised bar that supports the fuel bottle is the right dimension to support one, but it’s not a requirement.

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It may not be an essential item of Lambretta equipment, but if you find yourself building an engine and no spare chassis to try it on, it will save a lot of bother and time having to swap engines. Even if you do have a frame waiting for the engine. It’s an easier way of testing an engine before fitting. An example being, If you find an issue that needs the top end stripping, it’s a hell of a lot easier to do with the engine out the Lambretta.

There’s really not much to it and it’s very easy to put together. Just attach the CDI, fill the bottle with fuel and fire up the engine.

Jon, makes various parts and tools for Lambrettas. He can be contacted on his Facebook page.

JB Fabrication Facebook Page

Taylor Tuning Leak Down Test Kit

Some people say it’s a new fad and we got on fine before but in reality we didn’t or we were lucky

Leak-down test hysteria, another internet hype

Two quotes from Social Media. One is sensible.

Contrary to what some people may think, a leak down test can be one of the most important jobs to carry out on a Lambretta. It will expose any leaks around the cylinder or cylinder head, mag housing, inlet manifold, exhaust port and both mag side seal and drive side seal. Any leak from these areas can make correct jetting and set up almost impossible and may lead to serious damage to your engine.

I was introduced to the leak down test by Darrell Taylor of Taylor Tuning through a couple of social media outlets. Up to this time I wasn’t aware such test existed, let alone anything for a Lambretta.

I’ve battled jetting on many occasions and one particular time that stands out was when I was trying to jet my 250LC. Rich low down, lean on high revs. Whatever I tried, I just couldn’t get the jetting right. The fault was only discovered by Alan Terry of Diablo Moto, on my way to Mersea Island Scooter Rally in 2012. There was a crack at one of the barrel studs on the casing, causing an air leak. This ended the journey.

A leak down test on the engine build would have spotted this.

So, fast forward to 2016 and I purchased one of Taylor Tunings leak down test kits as well as a blood pressure gauge.

Darrell Taylors Kit comprises of various bungs for various sizes of inlet manifolds and round and oval blanking plates & rubbers for the exhaust outlet. You can also buy an upgraded version that includes a pump, but as I already had the blood pressure gauge, I didn’t need it.

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I’m currently building a TS1 230 engine and it was time to do the leak down test. Using Threebond on the gaskets, the first test was done with the pressure pumped up to approximately 300 mmhg or 6PSI. The gauge was dropping very slowly at 1PSI over two minutes. I could have let this pass as acceptable, but I couldn’t find the source of the leak so didn’t want to leave it. A brief conversation with Colin Jenkins and he suggested Drive side and mag side oil seals. He was right. A squirt of soapy water revealed the Drive side oil seal was the culprit leaking.

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Replacing a drive side oil seal isn’t the easiest repair on a roadside, so I took the top end apart and put in another seal. The air pressure held held this time.

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One good point Darrell recommends with any engine failure, always get a Leak Down Test done before stripping the engine.  This will save time and money and may point you to the source or cause the failure!

Benefits of a Leak Down Test:

This test will help find the potential problem rather than trying to find the problem of a leak without knowing it’s source, which in turn could lead to a wrong diagnosis, causing further engine trouble.

The leak down test gives you confidence with your engine build.

It should also be used to find the cause of an engine component failure, again with a better chance of finding the real cause rather than a guess.

So why wouldn’t you? Nearly all good quality engine components are not cheap, so it pays to protect the engine.

 Taylor Tuning Facebook Page

JB Fabrication Lambretta Engine Stand

For a number of years, I’ve got along stripping & building my Lambretta engines with the usual huff and puff when I always have to turn the casing around, working on different parts of the engine.

Apart from when I had big enough space to build my own workshop to store and work on my Lambrettas, I’ve always found it difficult to utilise work space for a workbench, but recently I built a small bench on wheels that I can use for working on my Lambretta engines.

So with this I was looking for an engine stand that was suitable and there’s now a few to found. I was aware of John Betts of JB Fabrication and his work and when I found he was making the engine stands, it was the obvious choice for me as he has a reputation for quality workmanship and innovative.

The engine stand comes with two bolts. One holds the base to the engine stand and the other holds the swivel in any one of the 8 positions. You will need 2 bolts to fix the engine stand to your bench.

Fixing to the workbench is simple. Two bolts through the holding bracket to the bench, but make sure the bracket that holds the engine has space to rotate and protrudes from the work bench an inch or two. (see images at the bottom of the page). The longest bolt holds the two pieces together and as previously stated, the short Allen bolt keeps the holder in any one of 8 positions.

When fitting the engine to the stand, the rear shock bar goes through the hole and the engine mount goes over the other side. Then fit the engine bar through. Make sure you fit the necessary nuts for added safety. You’ll notice in the images I didn’t use nuts as the engine fitment was for photographic purposes only.

All I can say is this makes all the difference and everything is far easier when building a Lambretta engine. The 8 positions mean that you can do just about any work on the engine without the hassle of tipping the engine or having to stick something underneath to support it and no more nipping fingers turning it over.

JB Fabrication also sells these with a bracket that bolts the stand to a wall.

Jon’s work doesn’t limit to Lambretta tools and Lambretta fabrication work. He also does a wide range of work for cars and bespoke parts.

JB Fabrication Facebook

Magneto Bearing Track Removing Tool

When you change the Magneto side bearing, you have to replace the bearing track that comes with the new bearing. I used to grind it off (carefully), but its a bit tricky and easy to mess things up. This tool changes all that. It’s got spring loaded clamps, that when tightening the two bolts on either side, grip the sleeve on the inner edge. All thats left is to tighten the bolt on the top and it pulls off the sleeve.

Cutting Holes

In March 2010 I needed to cut a couple of holes in the legshield toolbox for a water temperature gauge and a EGT gauge

I had to cut two holes in the top for the water temperature gauge & the EGT gauge. In the past I’d mark a hole and drill lots of small holes around the mark, drill out larger holes. Then filing the edges until it was neat and tidy. This can sometimes take a while.

I got a hold of a 52mm Q Max hole cutter and went about cutting the two holes. In no time at all I had two perfect holes with no rough or sharp edges and no filings anywhere. They can be purchased from any number of online retailers.