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Re: Leak testing

Posted: Sun Nov 15, 2015 10:00 pm
by alanscottj
ming wrote:If it helps at all I recently went through this exercise with the engine in situ and posted my findings on the LCUSA: http://www.lambrettaclubusa.net/topic/3 ... wn-tester/

One thing I've discovered is that it's near impossible to achieve a gas-tight seal at the spark plug, so take that into account. In practice when things warm up the plug hole shouldn't be an issue. In my case the major culprit turned out to be a leak in the intake manifold.
Ming, you are an absolute legend! Your post is awesome, thank you so much for taking the time to write that up. Gonna put myself together a proper little leak testing kit and read every word of the attachment! NICE ONE :D

Re: Leak testing

Posted: Sun Nov 15, 2015 10:24 pm
by dennis
I put rubber o rings on my plug when i did my test.

Re: Leak testing

Posted: Mon Nov 16, 2015 12:48 am
by alanscottj
dennis wrote:I put rubber o rings on my plug when i did my test.
Great idea ;)

Re: Leak testing

Posted: Mon Nov 16, 2015 4:45 pm
by alanscottj
I have just ordered all of the parts to put together a leak down test and it has cost less than £20 - slightly less than the re-line of my second barrel at Langcourts @ £140 a pop!

Re: Leak testing

Posted: Tue Nov 17, 2015 12:07 am
by ming
alanscottj wrote:
dennis wrote:I put rubber o rings on my plug when i did my test.
Great idea ;)

Indeed. Good call.

Re: Leak testing

Posted: Tue Nov 17, 2015 3:48 pm
by YAMLAM
alanscottj wrote:I have just ordered all of the parts to put together a leak down test and it has cost less than £20 - slightly less than the re-line of my second barrel at Langcourts @ £140 a pop!
would you like to give us a run down of parts used and where from ?
been using the "inner tube " set up but would like something a bit more Pro.

Re: Leak testing

Posted: Tue Nov 17, 2015 4:45 pm
by alanscottj
would you like to give us a run down of parts used and where from ?
been using the "inner tube " set up but would like something a bit more Pro.[/quote]


If you have a look on page 1 Ming has kindly provided a link to his excellent write up on making a tester, I have pretty much used the same bits from EvilBay, he has also posted a link to a fantastic article on leak testing engines, a great read.

http://www.ebay.co.uk/itm/381374828384? ... EBIDX%3AIT
http://www.ebay.co.uk/itm/321910494513? ... EBIDX%3AIT

The first link is for the blood pressure tester - I bought this first and then found a better gauge later, the second link. I will use the tube and the balloon pump so might have a spare gauge going if anyone wants it ;)

Re: Leak testing

Posted: Tue Nov 17, 2015 7:02 pm
by wack 63
Here's one I knocked up with a plumbers expanding bung and some turned down nylon, double ended for 30 and 35 mm carb rubbers. I've also got a plug and rubber for standard inlets and a kit for Vespas. Image

Re: Leak testing

Posted: Tue Nov 17, 2015 11:31 pm
by YAMLAM
Many Thanks.

Re: Leak testing

Posted: Mon Nov 23, 2015 11:28 pm
by alanscottj
Tested mine on a Mugello 186 that I'm building, works great, just the slightest of leaks to find :roll:

Image