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johnny650
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Main scooter: lambretta 64 li 150 Special
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Thu Jun 07, 2018 3:26 pm

I know I know its a rubbish title but nothing sensible would fit in the title block.

I have a 64 LiS Special into which I have fitted a series 3 crankcase fitted with standard silent bush blocks . These blocks are of course considerably larger diameter than the original OEM TV/LiS blocks

Now I have found that there is insufficient clearance to the LH block to fit the Jetex 22mm carb without fouling the carb input spigot. !

The engine is a Indian 200cc small block kit to which I have fitted a standard 22mm small block inlet manifold .

Is there a simple way around this clearance issue ?

Is there a long spigot inlet manifold or one with a slight offset built in ?
Now i come to think of it I seem to remember some article about a dealer coming across a scoot where the owner had used a grinder on the silent block mount to create some clearance and the engine had fallen out .... :lol: :lol: :lol:

I don't wish to retrofit some early small mounting blocks because .......a. its a lot of work removing the engine and refitting it again and b. there is a very high probability of breaking one of the crankcase mounting wings off which would leave me with a very expensive shed door stop .

a.lo.v2
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Thu Jun 07, 2018 4:58 pm

the larger blocks would have been fitted to your bike originaly. and allow the fittng of the usual carbs i.e 18/20/22 dellorto. the problem will be with the manifold if not original or more likely the barrel if it is one of those linered alloy indian jobs as they are known to have the inlet surface machined incorrectly

johnny650
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Thu Jun 07, 2018 8:21 pm

a.lo.v2 wrote:
Thu Jun 07, 2018 4:58 pm
the larger blocks would have been fitted to your bike originaly. and allow the fittng of the usual carbs i.e 18/20/22 dellorto. the problem will be with the manifold if not original or more likely the barrel if it is one of those linered alloy indian jobs as they are known to have the inlet surface machined incorrectly
thanks but that is actually not correct.
The early LiS150 special and the TV both shared the small block and were both uniquely painted Neuvo white to match the rest of the scoot.

The engine I removed to fit this one was the original 64 LiS 150 S3 with the small diameter mounting mounting block . To use a 22mm carb you simply pack the original 18mm inlet or fit a 22mm small block aftermarket manifold which i have done.
however when you fit a later series 3 crankcase they are invariably fitted with the larger diameter silent mount type blocks

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Muttley McLadd
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Thu Jun 07, 2018 10:37 pm

Is $$ a considering factor? Would swapping out the solid mount type carb to something like a TM24 be an option?
CakeAndArseParty

johnny650
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Main scooter: lambretta 64 li 150 Special
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Thu Jun 07, 2018 11:21 pm

Muttley McLadd wrote:
Thu Jun 07, 2018 10:37 pm
Is $$ a considering factor? Would swapping out the solid mount type carb to something like a TM24 be an option?
yes that would definitely be an improvement for sure but this is simply a cheap spare engine to keep me running whilst I rebuild my original engine .I really don't want to spend any more money on it as Its just going on the shelf in the shed when I've rebuilt my original engine.
Thanks for the suggestion.

Meds1
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Sat Jun 09, 2018 6:23 pm

Interesting as my 64 lis came with tlarger blocks that had the remnants of the white paint showing.

bristolmod
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Main scooter: Lambretta TV175 S3- what else!
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Sun Jun 10, 2018 4:30 pm

johnny650 wrote:
Thu Jun 07, 2018 8:21 pm
a.lo.v2 wrote:
Thu Jun 07, 2018 4:58 pm
the larger blocks would have been fitted to your bike originaly. and allow the fittng of the usual carbs i.e 18/20/22 dellorto. the problem will be with the manifold if not original or more likely the barrel if it is one of those linered alloy indian jobs as they are known to have the inlet surface machined incorrectly
thanks but that is actually not correct.
The early LiS150 special and the TV both shared the small block and were both uniquely painted Neuvo white to match the rest of the scoot.

The engine I removed to fit this one was the original 64 LiS 150 S3 with the small diameter mounting mounting block . To use a 22mm carb you simply pack the original 18mm inlet or fit a 22mm small block aftermarket manifold which i have done.
however when you fit a later series 3 crankcase they are invariably fitted with the larger diameter silent mount type blocks
I don't understand what you are trying to say. All TV's and LI Specials had the large silent blocks fitted- and yes the early ones were painted white. No S3 TV's or LIS's had the small "LI" silent blocks from new.

You can get round your problem by slightly elongating one of the inlet manifold holes, which will allow it to "swing" slightly to the rear, thus avoiding the silent block.

Chris
Scootering since 1968.

johnny650
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Mon Jun 11, 2018 12:08 am

well that interesting because I have never seen an early LiS150 with the larger diameter blocks and I've seen many dozen on ebay over the past 4 years. I have numerous images I have saved and I don't recall a single early silver LiS with large blocks .

I'll have another look though some of my reference books and various images I have of the early white painted blocks and check.
The blocks fitted to this late crankcase are considerably larger in diameter that those fitted to the original LiS engine.

Unfortunately I am unable to swing my manifold due to excessive porting work on the barrel ,....presumably why they were sold so cheaply.

There are other alternatives that have occurred to me since such as offset cones and extending the manifold length

johnny650
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Mon Jun 11, 2018 12:49 am

Here is an image of the original mounts on my 64 LiS150 and as you can see they are smaller in diameter with a short bar and not the larger silent pattern mounts of the late series 3
Image

bristolmod
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Main scooter: Lambretta TV175 S3- what else!
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Mon Jun 11, 2018 7:55 am

The pictures not brilliant but that appears to be a normal larger engine mount- there appears to be the remnants of the usual white paint thereon.

Innocenti produced two engine mounting systems- all S3 LI models and anything before used the short bar with the engine mount totally enclosed within the engine spigots

All S3 LIS's;TV's; SX's; GP's etc used a long bar with engine mounts that were located in the engine spigots but were longer to allow a "softer" engine vs frame location.

Yours is the later version

2 versions only. Not a 3rd version that was somewhere between the 2.
Scootering since 1968.

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