Px cylinder on lml motor

[midcheshire20]

I have recently put an italian standard 150px (new) barrel and piston onto a late lml 125, is this a poor set up ? , wasnt after any land speed records but after running in when you go from 3rd to 4th its like going into 5th, a lot less oomph than before. I was just after a 55mph cruising speed and inclines easier, i havnt got that ,i ubderstand it will loosen up a bit but are the two not suited , cheers any hints.

[midcheshire20]

P.s the reason its a standard italian barrel is the indian 5 port i bought was shocking quality,and was not genuine lml even though the add said it was.

[3narf]

Hmm... all PXs are 3 port so the barrel & piston you fitted isn't compatible. If you have a 5-port LML engine you need a T5 cylinder, or a kit for a T5...

[midcheshire20]

This in hindsight is what i feared,great starter,nice tickover,nice plug colour, ok through the gears, respectable anyway but have to take the revs right up before 4th, reluctant to cane it just yet obviously.It potters about ok it just hates inclines and headwinds ,cgeers for your input.T 5 barrel, so that a staight fit? Would need an exhaust ,different coupling ? .

[3narf]

I think the T5 barrel fits an LML 5-port; I would hope so because there are only two types of kits for a P-range '150' case. You are right, I think - T5 exhaust coupling is different so you'd need another exhaust, too...

[midcheshire20]

Cheers, i will just get a few more miles on it as and when, not that we can do much at the moment, a genuine lml 5 port maybe the way to go, so many crap copies out there though.I do know the t5 barrel needs a different exhaust for sure.

[shaunbond]

OK to summarise.

The the LML and Vespa cases are the same (T5 are different), however the ports on the LML are usually bigger , I say usually as some, especially later ones, are normally the same size as the Vespa.
The cylinders however are different, the Vespa is a true 3 port but the LML is a bridged 5 port which are bigger than the Vespa.

If you put a PX cylinder on a big port LML case then you're not using its full potential, if it's a small port LML then it's just like a PX set up. Which on a 125, crusing at a true 55 won't be possible, flat out yes but not crusing.😀

The LML large port mated with the 5 port cylinder is a brilliant set up, plenty of torque if not a lot faster flat out, unless you fit a 22 tooth clutch centre. Ensure you get a genuine kit though if you go this route as there are some shocking examples.

Long summary 😂 hope this explains things

[shaunbond]

Edit just read you fell into the poor kit hole, sorry to rub it in...

[midcheshire20]

Thanks shaun, as you now know the lml 5 port online wasnt as advertised,i still fitted it and couldnt have run it in anymore gently ,it still kept soft seizing very close to home,so i couldnt even run it in. So i hoped the larger capacity standard italian cylinder would be ok but i havnt gained anything.Its hard to trust any advert now for an lml 5 port online..my new kit had lml 2t on the list of supposed suitable models ,🤔.

[shaunbond]

As you've found it will fit and will be fine, I wouldn't worry about it to be honest. With any standard cylinder your never going to get a powerhouse but should get a good reliable plodder.

I guess the LML kit had a tight clearance, a good gone should sort it along with ensuring the posts are nice and smooth.

[midcheshire20]

Yeah mate, its not a disaster at the moment, as it loosens up i will then give it some through the gears rather than nurse it into 4th.It sounds lovely with the sip 2 on ,its always had that on btw.. i still have the oridginal 125cc 5 port cylinder kit 😁, ground hog day 🤔.

[shaunbond]

Don't treat it to gently just ride it normally, not thrashing it or labouring it in too high a gear. Sorry if that's teaching you to suck eggs

[midcheshire20]

No don't worry im not offended, i will be less gentle with it now.Nothing to lose and i have the oridginal 125 set up that was bullet proof to be fair as back up.