replace stock cylinder

[alloo66]

My motor seized unexpectedly. Now I have a choice replace the stock cylinder with a stock one or get a 166 cc performance kit or a 166 HP kit from Scooterworks. Not sure, which option is the best. I know the cost of both kits, but not the stock one. Any tips are welcome. I'm not sure how the bike should run stock or otherwise. What about reliability?

[BuddyRaton]

How bad was the damage? Have you pulled the head and jug?

Picking a kit depends on what you want to get out of the motor. If your thinking 166 I assume your looking at the Malossi. Good kit, loves high revs, needs some porting work to get the most out of it and will need to (at a minimum) rejet. Other kits like the DR and Pinasco are more for a touring set up so it depends on what you want.

You could also rebore your existing jug and go with first oversized piston but sometimes it is more economical to go with a new top end.

[Lokky]

from what I understand the 166 malossi is more of a racing kit. It has plenty of power and wants to do wheelies, but you should not expect a long lifetime from it.

I have the aluminum 177 Pinasco and it is absolutely great. Not as much lower end grunt as other kits but still a big jump from stock and it can withstand WOT for long periods of time no problem (I rode 1k miles each way to Amerivespa keeping it WOT the entire time on mine).

The big thing to do if you want to kit it however is to change out your crank. The LML crank is unlikely to last very long on a stock engine, much less with the power of a kitted one.

[alloo66]

I just want a reliable scooter. Not sure what the stock replacement costs, but thought a kit may be cheaper. I do mostly suburban to urban commuting and riding. Lots of 40+ MPH riding.

[Stitch]

The iron dr177 has decent mid range torque. It gets my dainty 260lb butt up mountains in third gear (usually).

[BuddyRaton]

I just want a reliable scooter. Not sure what the stock replacement costs, but thought a kit may be cheaper. I do mostly suburban to urban commuting and riding. Lots of 40+ MPH riding.

If you were happy with how it was running I would first pull the head and jug and inspect. If the damage isn't too bad you may get away with a little sanding. If scored up I would look into a rebore and first oversized piston

[fisher1]

My motor seized unexpectedly.

Have you determined what the cause was & how you are correcting it?

[BuddyRaton]

My motor seized unexpectedly.

Have you determined what the cause was & how you are correcting it?

Good point! Every time I have seized one I knew why...basically because I was doing something stupid!

[Stitch]

Hey look. Yet another '09 seized. Must be my imagination. Somewhere around 1200 to 1500 miles?

[alloo66]

My motor seized unexpectedly.

Have you determined what the cause was & how you are correcting it?

Good point! Every time I have seized one I knew why...basically because I was doing something stupid!

Thanks I think I was running the bike hard everywhere trying to find out how fast the bike would go. It's my first Stella. Or maybe the exhaust was plugged up. I've had mopeds that would beat this bike easily. So maybe the bike didn't run well. I'm also going to replace the flywheel seal.

[BuddyRaton]

I'm also going to replace the flywheel seal.

why? what EXACTLY happened when the motor seized?

[alloo66]

The idle went up and the motor died, while idling and you heard a grind until the motor stopped. The cylinder was scoured on the intake side.

[Stitch]

The idle went up and the motor died, while idling and you heard a grind until the motor stopped. The cylinder was scoured on the intake side.

Ok, that's not the same failure we were having.

[alloo66]

My bike has 4300 miles never quite ran like a 150cc two stroke.

[lorenajack]

My 2005 Stella blew the 150 piston and cylinder at around 8,000.
I got a 166cc Malossi replacement.
Two weeks later, engine seized.... crank bearing destroyed probably
because of the increased torque from the new 166.

Long story short ... after a few months of screwing around (long story)
I split the case, replaced all the bearings with Italian made, new Mazzuchelli crank (kind used in Vespa I think), Sito+ muffler...all purchased from ScooterWest (Max is parts guy...very helpful). All new gaskets of course. Be SURE to chamfer your ports on the 166 cylinder!!! VERY important if you don't want your new rings to hang up on the intake and exhaust ports. YouTube has a video on this!!!

After some screwing around with jetting (160air, BE3 mixer, 109 main) and a 55-160 idle jet it runs like new. Jetting can be a nightmare.. but what I just wrote is what worked for ME! I am in Tucson...jetting is critical to your elevation. Max at ScooterWest can help here too! Guy is GREAT!!

[alloo66]

My 2005 Stella blew the 150 piston and cylinder at around 8,000.
I got a 166cc Malossi replacement.
Two weeks later, engine seized.... crank bearing destroyed probably
because of the increased torque from the new 166.

Long story short ... after a few months of screwing around (long story)
I split the case, replaced all the bearings with Italian made, new Mazzuchelli crank (kind used in Vespa I think), Sito+ muffler...all purchased from ScooterWest (Max is parts guy...very helpful). All new gaskets of course. Be SURE to chamfer your ports on the 166 cylinder!!! VERY important if you don't want your new rings to hang up on the intake and exhaust ports. YouTube has a video on this!!!

After some screwing around with jetting (160air, BE3 mixer, 109 main) and a 55-160 idle jet it runs like new. Jetting can be a nightmare.. but what I just wrote is what worked for ME! I am in Tucson...jetting is critical to your elevation. Max at ScooterWest can help here too! Guy is GREAT!!

Thanls ! Seals are known to go bad also.