Thu Jun 03, 2021 6:27 pm

Enthusiast
'81 Vespa P200e, '85 Vespa PX125e, '70 Vespa 90 basketcase
Joined: 11 Jun 2020
Posts: 91
Location: St. Catharines, Ontario
 
Enthusiast
'81 Vespa P200e, '85 Vespa PX125e, '70 Vespa 90 basketcase
Joined: 11 Jun 2020
Posts: 91
Location: St. Catharines, Ontario
Thu Jun 03, 2021 6:27 pm linkquote
Hey all,

I am sure many of you have read about my trials and tribulations about the DR180 kit I installed on my px125e vespa.

It runs like garbage. The kit is absolute junk and the cylinder head is either warped or defective. I had it machined and lapped and the surfaced mated but I was still experiencing a leak from the base of the cylinder head and a pinging noise that could wake the dead.

A friend of mine had dropped off a LML 150 cylinder set. It has a gasket between the cylinder and the head. So another friend and I took that gasket and slid it between the surfaces of the DR kit. Instant improvement. Minimal pinging noise and no leaking.

So here is my question:

Should I just swap the DR180 kit (with the warped head and unsure if the gasket is safe to use) for the LML 150 and call it a day?

How much difference in performance will I achieve? I will be pairing the cylinder with sip road 3.0.
I have previously read that folks consider swapping their stock px125 cylinder for the LML 150 or the DR180.

Any suggestions or recommendations are appreciated.
Thank you.

N
Thu Jun 03, 2021 9:16 pm

Ossessionato
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 61 Ser 2, 65 Silver Special, 86 & 96 Elite 80s, 2015 HD Road Glide Special, 2011 Ural Tourist
Joined: 18 Jan 2012
Posts: 3995
Location: Oceanside, CA
 
Ossessionato
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 61 Ser 2, 65 Silver Special, 86 & 96 Elite 80s, 2015 HD Road Glide Special, 2011 Ural Tourist
Joined: 18 Jan 2012
Posts: 3995
Location: Oceanside, CA
Thu Jun 03, 2021 9:16 pm linkquote
Hmm I just worked on a DR180 kit on a Stella yesterday. Definitely an improvement over a 150 and no problems with a head leak/pinging etc.

I donít see a problem with the gasket if your squish gap doesnít get thrown too far from spec. 1-1.5mm for a mild engine. Can you measure with and without the new gasket and see what it reads?

Obviously you donít want pinging or a head leak so if it works, run with it till it doesnít and then try the LML cylinder.
Thu Jun 03, 2021 10:03 pm

Molto Verboso
One or two fun scoots....nothing too precious
Joined: 17 Jul 2013
Posts: 1698
Location: UK (South East)
 
Molto Verboso
One or two fun scoots....nothing too precious
Joined: 17 Jul 2013
Posts: 1698
Location: UK (South East)
Thu Jun 03, 2021 10:03 pm linkquote
I have run DR kits on two occasions and think the cylinder is pretty good. It has the auxiliary exhaust ports and the base transfers can easily be enlarged and matched to bigger case ports. For a budget kit, there is a lot you can do, if you are so inclined. The common complaint with the piston (thick rings) can be overcome with a Grand Sport piston if you can find one, and the other complaint is the sloppy piston to bore clearance which makes it a noisy kit. Most can live with that. I didn't buy the GS piston, but I did run superior 63mm GS rings with my first kit.

As far as the head is concerned, they are junk. I used a Polini 177 head on my first one and a VMC 177 head on my current one. The Polini is cast better and reduced the BIG squish. The VMC is a CNC milled beauty, with a central combustion chamber and long reach central plug, and it allowed me to lift the cylinder to improve the port timing, whilst still keeping the squish sensible.

Whatever you do (DR or LML 150), you will get better performance than a PX125. If I were you, I would invest some Dremel time into the DR kit, then get a better head and the GS rings. There is no need for the head gasket, other than to compensate for poor engineering, which is probably why the LML top end uses one.

Alternatively, there are many other 177 kits available.
Fri Jun 04, 2021 7:34 am

Ossessionato
1963 VBB2T
Joined: 07 Nov 2012
Posts: 2511

 
Ossessionato
1963 VBB2T
Joined: 07 Nov 2012
Posts: 2511

Fri Jun 04, 2021 7:34 am linkquote
swa45 wrote:
I have run DR kits on two occasions and think the cylinder is pretty good.

As far as the head is concerned, they are junk. I used a Polini 177 head on my first one and a VMC 177 head on my current one. The Polini is cast better and reduced the BIG squish. The VMC is a CNC milled beauty, with a central combustion chamber and long reach central plug, and it allowed me to lift the cylinder to improve the port timing, whilst still keeping the squish sensible.

Well thatís not a reassuring point about the head , but good to know.
Fri Jun 04, 2021 7:52 am

Molto Verboso
Joined: 03 Nov 2011
Posts: 1251
Location: Racing Capital of the World
 
Molto Verboso
Joined: 03 Nov 2011
Posts: 1251
Location: Racing Capital of the World
Fri Jun 04, 2021 7:52 am linkquote
The DR177 cylinder kit has to be 30+ years old. It is old technology and in no way produces the power and quality of todayís cylinder kits in the market.

Brand new, these sale for $200.00. Thatís cylinder, piston, rings, and head. That is extremely cheap.

I would figure this: itís near a stock 3-port cylinder with 27 extra CCís. You will not be doing cartwheels with these bad boys.

All that being said, they work and are an okay replacement for any unmodified 3-port cylinder. If you want more in both power and quality, pay more money. Itís that simple.
Fri Jun 04, 2021 7:56 am

Molto Verboso
Joined: 03 Nov 2011
Posts: 1251
Location: Racing Capital of the World
 
Molto Verboso
Joined: 03 Nov 2011
Posts: 1251
Location: Racing Capital of the World
Fri Jun 04, 2021 7:56 am linkquote
Nelluch125 wrote:
Hey all,

I am sure many of you have read about my trials and tribulations about the DR180 kit I installed on my px125e vespa.

It runs like garbage. The kit is absolute junk and the cylinder head is either warped or defective. I had it machined and lapped and the surfaced mated but I was still experiencing a leak from the base of the cylinder head and a pinging noise that could wake the dead.

A friend of mine had dropped off a LML 150 cylinder set. It has a gasket between the cylinder and the head. So another friend and I took that gasket and slid it between the surfaces of the DR kit. Instant improvement. Minimal pinging noise and no leaking.

So here is my question:

Should I just swap the DR180 kit (with the warped head and unsure if the gasket is safe to use) for the LML 150 and call it a day?

How much difference in performance will I achieve? I will be pairing the cylinder with sip road 3.0.
I have previously read that folks consider swapping their stock px125 cylinder for the LML 150 or the DR180.

Any suggestions or recommendations are appreciated.
Thank you.

N
My suggestion: VMC177! best to TIG weld up the cases and match the transfers, but you could also install it as-is. Would work circles around the two cylinders you have referenced.



Wed Jun 09, 2021 12:19 pm

Hooked
PX
Joined: 28 May 2020
Posts: 146
Location: Bognor Regis
 
Hooked
PX
Joined: 28 May 2020
Posts: 146
Location: Bognor Regis
Wed Jun 09, 2021 12:19 pm linkquote
Might you not try another 177 kit? OK you had bad luck with your DR but how about a Malossi or something recommended on here? The lml 150 bolt on makes very little difference on a 125 performance. I've tried this and got the lml kit still in shed as it was barely noticeable. It has a couple of extra boost ports in it. If you are just looking to get your scoot running again it will be fine and reliable I'm sure but you won't notice a lot of difference.
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