2003 LML Stella clutch oddities

hjarvis · Post by **hjarvis** » Tue Nov 12, 2013 6:49 pm

Hi, everyone. I have an '03 LML engine installed on my '74 GTR. I appreciate the CDI and 12 volts, but occasionally run into some unexpected weirdness.

For example, my clutch literally exploded at a light recently. When I got the cover off, the plates were all sprung loose from the bell and spinning freely. Not sure why this happened -- perhaps it really overheated or the clip was substandard..? But I don't see any glazing.

Anyhow, I won't rebuild the unit -- not worth the risk, so need a new complete clutch assembly. But unlike what I expected for a Stella engine, it had a 22 tooth 6-spring unit (not the expected 7-spring). And there was no gasket or o-ring on the cover, or even a groove for an o-ring. Also there was no thrust washer.

If it's significant, because it's on a non-battery GTR, the electric start is removed, and the oil injection is not being used.

Appreciate any insight!

viney266 · Post by **viney266** » Wed Nov 13, 2013 2:18 am

The later Stellas are 7 spring and 21 tooth. The clip must have let go. I have seen them get grabby on built motors, but never on a stock motor. Me?...I would go with a better clutch, I am a fan of a banded Cosa. It all depends on your wallet, SIP makes a REALLY nice one complete if you have $230. Thats sprocket, and complete clutch, a real nice piece. My 08 Stella has an oring on the cover.

hjarvis · Post by **hjarvis** » Thu Nov 14, 2013 4:01 pm

I'm still not used to what fits a Stella engine, especially with this odd 2003 version. Is it a VNX..??? P150? PX150?

Anyhow, I like your idea of a better clutch. Happy to spend a couple hundred on a new one. Having troubl enavigating SIP's site. Which model of Cosa clutch would fit..?

And is there really no thrust washer behind the clutch?

Thanks!!

hjarvis · Post by **hjarvis** » Sun Nov 17, 2013 11:20 pm

Ok, I will admit I missed seeing the o-ring. Now I've dropped the engine and wiped the rest of the grease off, I see it embedded in the lip of the cover.

But my question about the lack of a thrust washer, and which model engine this equates to still stand. Anyone have their ears on..?

az_slynch · Post by **az_slynch** » Mon Nov 18, 2013 5:36 am

The Stellas are similar to a EFL Vespa PX in the transmission section. The clutch is interchangeable with most of the autolube-equipped 80, 125 and 150cc Vespas, (e.g. the Super, the Sprint, the TS and the VNX P/PX-Series). It's a six spring clutch with a 108mm outer diameter. The larger seven spring ones go on the Rally models, the T5s, the VSX P/PX200s and the Atomic Fireball Stella; this clutch has a 115mm outer diameter. The larger clutch will not fit under the non-Fireball Stella clutch cover unless you grind back the oil guide for the clutch throw-out assembly a bit.

The washer only goes behind the clutch if you don't have a drive gear for an autolube system. Otherwise, the autolube gear does that job. If the clutch doesn't seem to be disengaging no matter how you adjust the clutch, you probably need to replace the brass bushing and brass spacer washer in the clutch assembly.

hjarvis · Post by **hjarvis** » Mon Nov 18, 2013 3:36 pm

Thank you so much, az_lynch.

(Been peaking at the LML website, and they don't even provide this level of detail... their diagrams suggest all have the 7-spring clutch.)

Someone suggested this might be a good opportunity to put in a better model clutch, they mentioned a Cosa. Would this make sense..?

SIP also lists a NEWFREN Cosa 2. If that's a good direction, the standard model sounds like the right direction (details).

Again, many thanks! Once I finally get a handle on this engine, I will feel much happier.

az_slynch · Post by **az_slynch** » Mon Nov 18, 2013 3:49 pm

The Cosa clutch gets its name from the bike it was designed for, the Vespa Cosa. It will fit onto the crankshaft with no issues, but you will need to get a Cosa-specific clutch nut and lockwasher to install it. Like the 7-spring clutch, you might need to grind the clutch cover's oil guide if you use the bigger (200cc Cosa)clutch.

The big perk with the Cosa clutch is that its design uses smaller springs for easier clutch action, but more springs to ensure more uniform clamping action. Many riders swear by them. Personally, I've never needed more than a Malossi plate set and new stock springs on my P200.

hjarvis · Post by **hjarvis** » Mon Nov 18, 2013 5:05 pm

Point taken.

The Cosa might work for me then, since I won't be reusing my current basket.

Will it take much to clear the path on the cover...? It's just white metal right?

az_slynch · Post by **az_slynch** » Mon Nov 18, 2013 7:30 pm

The cover is aluminum and can be easily taken down with a file or a Dremel with a sanding drum.

I don't have one easily accessable for reference, but the ribs of the oil guide need to be ground down out near the periphery, particularly near the "edge" of where the clutch basket face will run. I believe this link is the info you're looking for.

hjarvis · Post by **hjarvis** » Mon Nov 18, 2013 8:31 pm

Ah, got it. Guessing the cover is more curved than the top of the clutch basket. Is there a concern with removing too much of the oil guide..?? Hate to starve it.

az_slynch · Post by **az_slynch** » Mon Nov 18, 2013 10:16 pm

It won't be an issue. Trim it according to the diagram on the BGM website that I linked previously and you'll be fine. Just be sure to clean your clutch cover thoroughly after the work and put a fresh dab or grease in between the clutch push pin and the clutch actuator arm.

If you're really feeling feisty, remove the push pin, the clutch arm spring, slide the actuator arm off the shaft and pull out the shaft. Replace that silly O-ring in the bottom of the clutch cover tunnel that's worn out and leaking oil. Polish and lightly grease the shaft when reinstalling so the o-ring doesn't pop out or twist up. Sounds like a pain, but it's worth it if you can keep the oil inside the motor, especially if you have to work on it later!

hjarvis · Post by **hjarvis** » Mon Nov 18, 2013 10:18 pm

Sorry, I completelymissed that link -- perfect.

Thanks again, you have been extremely helpful!

Tipper · Post by **Tipper** » Fri Nov 22, 2013 8:08 pm

Lml star's come fitted with the seven spring clutch as standard on this side of the pond.

It's strange that they fitted the six spring model for the US market,maybe you guys have a stronger grip than us !

az_slynch · Post by **az_slynch** » Fri Nov 22, 2013 10:05 pm

The 4T Stellas have the larger seven-spring clutch here, as did the Atomic Fireball Edition Stella. Rest of the old 2T Stellas I've worked on all came with the smaller six-spring clutch.

Tipper · Post by **Tipper** » Fri Nov 22, 2013 10:18 pm

That is odd,all LML star's (2t or 4t) come with the seven springer over here even the smaller capacity 125's. The only model with a different clutch is the 200 which has a beefed up motorcycle style clutch.

hjarvis · Post by **hjarvis** » Sat Nov 23, 2013 12:00 am

Apparently the early models were different -- LML confirmed it based on my engine number. Now I need to discover what else is different. Makes me nervous.

hjarvis · Post by **hjarvis** » Sat Mar 29, 2014 8:51 pm

ps. I should mention, the 2003 model LML engine apparently takes a 22 tooth clutch.

Modern Buddy

2003 LML Stella clutch oddities

2003 LML Stella clutch oddities

additional note on early model (2003) LML Stella clutch