Modern Buddy

That was an exciting trip. On the ride home from school, I was noticing that the motor sounded different. Wasn't sure what exactly, but I was hearing a throatier sound, especially when I would let off the throttle. Bike was riding ok, so I figured I'd just look at it when I got home. About 100 yards from my driveway I ran over something, got a little shaky but I stayed up fine. Looked back down the road and there was my muffler.

I've been hearing rattling under the scoot for a long time, wasn't too worried about it since most people report rattling, bet I know what it was now.

Worth checking yours maybe, running it over could have been pretty bad.

D'oh.

Did it break off or just fall off?

It's only held on by 3 mounts, A large bolt through it on the bottom of the engine and the two nuts threaded onto the studs coming out of the head.

Totally sheared the pipe right out of the motor. Weird. A couple weeks ago someone knocked the bike over in the parking lot, my insurance still trying to sort that one out. Could have been some damage with that.

Looks like it will be easy to replace. The mount under the scoot is still there, I suspect that is where it's been rattling. There is about an inch or two of pipe still coming out of the motor.

What part do I buy? I can only find performance exhausts on the web. Also should I look at a performance exhaust?

Your dealer may be able to get you a new exhaust, Otherwise you might just be the first person on Modern Buddy to have one of those newly forsale Sito's on their 4-Stroke Stella!

Got pictures?

I've heard of several people having their exhaust break right below the heat shield, Mine has broken there twice and now is held together with a really ugly weld from a local exhaust shop.

I'll go get some photos.

Here they are. Just noticed I damaged a cable too. Crap.

Yikes!

Better add new shift cables to your list of replacement items too, They look melted there.

Mine keeps breaking below the heat shield, Looks like yours broke above it.

Think your instance will cover it?

Here's the link to the new Sito for the 4-T Stella.

http://www.scooterworks.com/sito-plus-e ... -12475.php

That sito looks inexpensive enough. Do I just put it on or does it need tuning or anything like that?

My insurance may cover the repairs. I have liability, but I have uninsured motorist as well. My agent says as soon as the police report gets typed up she will see if the guy who knocked it over is covered (then go after his) or if he's not mine should cover it. Luckily it happened at the gov center and a security guard witnessed it and got the plates for the police. I already had the throttle fixed since it fell on that side and was really stuck. Also I'll be trying to get a new cowl cover for that side and painted. We'll see.

I think this is likely related, same side where the rest of the damage occurred.

Your carburetor may need to be upjetted after putting it on. Depends on how much more air it flows than the stock exhaust.

I see. If that's the case, I'll likely try and get the stock one.

Sounds pretty neat right now though.

Rejetting is cheap and easy. Don't let that put you off the Sito+
Is there a way to open it up to get more air flow to the carb? Like drilling the heart or de-blueing on a 2t air filter?

Well, I guess the good thing about the Sito is that it may not break welds as easily. But won't it likely put more stress on the motor (assuming there is some kind of performance increase)? I'm not really interested in a performance increase as much as I am keeping this thing running at least as long as my payments on it last.

Totally undecided at this point, but need to decide soon.

I say go for it.

If I wasn't currently unhappy with Scooterworks I'd order one myself.

If anyone has a rattling exhaust, bring it in to a dealer. If the weld is broken, it'll be replaced under warranty. If you ignore it and it causes further damage, that might not be fully covered.

Damage to the header or the studs can be a much bigger problem than just getting a new exhaust.

I wish I had known it was a rattling muffler back when I was under warranty.. I'd reported the sound before, but mechanics were never able to figure out what it was. I'm pretty sure I've even posted about it here before.

Hard to tell what's rattling when you have to be on the bike for the rattling to happen... But I'd say everyone check your mufflers specifically just to be safe.

Tom, check your posting history. If you posted publicly about a mysterious rattle back when you were under warranty, you might be able to make a case to Genuine and your dealer that the problem started during the warranty period. Worth a shot.

I think that anyone looking closely at the parts would know that it happened earlier. The weld on that main bracket failed, and it would take quite a while to shake through that main pipe. I will do what you suggest though and if I find it I'll link it here. I remember that when I posted about it, someone suggested I check inside the glove box for some famous problem, never found it. (Here's one, didn't say as much about it as I thought I guess. viewtopic.php?p=261932&highlight=#261932 And here is the other time where I mentioned that they looked for the rattle and thought it might be the center stand viewtopic.php?p=256404&highlight=#256404 Nothing was done for it at this time, but they did make a note on the paperwork. Oh! Just found a third time I mentioned the rattling- viewtopic.php?p=255400&highlight=#255400) I think another time someone suggested I check something near the front fork.. Nothing found there either. I guess if I fix it and it doesn't make the noise anymore, I'll know for sure.

The more I think about this, it's actually not likely to have been caused from tipping over. These parts simply wouldn't come in contact with the ground that way.

Just remembered! I made my first mechanic at Ventura Harley make a note that he wasn't able to find the source of the rattling!! Glad I did that. I'll see if I can find it too. I know I've saved all my service reports, just have to figure out where I saved them.

Genuine remains an incredible company to do business with. They have approved the claim, and are sending an exhaust and shifter cable to my mechanic.

Just want to be clear- they didn't have to do so, even though I believe it was the right thing to do. This is a sure sign that you are doing business with the right people! Thanks Genuine!

I noticed a little different sound coming from the engine the last couple of days and thought it was from the 30 degree temperature swings we were experiencing. Upon closer examination I found a small crack in my muffler below that collar and above the curve that goes to the larger part of the muffler. I guess about 3-4 inches below where the muffler broke in the above pictures. I meet The Blue Meanies Scooter Club on Saturday mornings at Moxie Scooters, my home shop. While I am there this week I will have them take a look at it and see if a weld will do the trick or if they will need to replace it.

My 4T Sito Plus came today, I plan to install it either later tonight when the bike cools down or in the morning before I go to work.

Looks like it's just plug and play according to the manual, No mention of jetting changes, Just bolt on and ride, and re-torque the bolts after 100km.

Nice! Let us know if it changes anything.

Fixed! Big thanks to Genuine and TO Powersports.

Just wanted to say, after it has been replaced, no rattling whatsoever. If you all are having rattling from under the scoot and thinking it might be springs on the centerstand.. it probably isn't do check it out.

JohnKiniston wrote:My 4T Sito Plus came today, I plan to install it either later tonight when the bike cools down or in the morning before I go to work.

Looks like it's just plug and play according to the manual, No mention of jetting changes, Just bolt on and ride, and re-torque the bolts after 100km.

I would love to hear more about the Sito pipe. Have you installed it yet?

Swapping the jets on a 4t isn't as easy as a 2t.
You have to remove the carb, flip it up-side down. Take off the bowl., change jets, put it back together. Good luck..

slotrod65 wrote:

JohnKiniston wrote:My 4T Sito Plus came today, I plan to install it either later tonight when the bike cools down or in the morning before I go to work.

Looks like it's just plug and play according to the manual, No mention of jetting changes, Just bolt on and ride, and re-torque the bolts after 100km.

I would love to hear more about the Sito pipe. Have you installed it yet?

Yup!

Put it on and ran a rally with it. I'm seeing a higher top speed and I'm climbing hills & mountains with a lot more ease now.

Lost the clamp that goes where the two halves of the pipe meet up, I'll probably rig something up to replace it.

JohnKiniston wrote:

slotrod65 wrote:

JohnKiniston wrote:My 4T Sito Plus came today, I plan to install it either later tonight when the bike cools down or in the morning before I go to work.

Looks like it's just plug and play according to the manual, No mention of jetting changes, Just bolt on and ride, and re-torque the bolts after 100km.

I would love to hear more about the Sito pipe. Have you installed it yet?

Yup!

Put it on and ran a rally with it. I'm seeing a higher top speed and I'm climbing hills & mountains with a lot more ease now.

Lost the clamp that goes where the two halves of the pipe meet up, I'll probably rig something up to replace it.

Being as a 4t,did you rejet? If so... What size are you running?
If not... Let us know how the plug looks...
Thanks.
This will help others putting on a 4t sito+.

No Re-jetting. Still running the stock setup for jets.

I'll be replacing my carburetor with a larger one as my next mod.

JohnKiniston wrote:No Re-jetting. Still running the stock setup for jets.

I'll be replacing my carburetor with a larger one as my next mod.

How does the new Sito sound, is it louder? I've been thinking about getting it but hardly know anything about it.

Louder than stock, Doesn't sound like a 2 Stroke Sito obviously

Maybe a bit rumbly now. Hard to say and the bike isn't running right now

JohnKiniston wrote:Louder than stock, Doesn't sound like a 2 Stroke Sito obviously

Maybe a bit rumbly now. Hard to say and the bike isn't running right now

No way, now what?

His charging coil for the CDI went ker-put. I think it shorted internally. New stator is on-order from Scooter works, as the stator is more like a GY6 than a 2T Stella but not close enough for a GY6 swap.

The Sito's biggest gain on a 4T appears to be mid-range torque. More top end would come from a bigger carb, a freer-flowing air filter, and a 22T clutch drive gear. All are on tap for making more go.

Ordered an engine gasket set for a little down the road. The 4T uses the same type gears as the 2T Stella and Vespa PX bikes, so I'd like to do tooth counts and fine-tune the gear ratio; just can't do that without the stuff to seal the case back up.

Hmmm.. a better breathing air filter is always a good idea. What is planned for the 4T?

I found a way to essentially "clone" the Pinasco carb setup for a lot less money with components from a web-based moped parts vendor. The carb is a 21mm Dell'Orto PHBG. The trick for building one up is to start with an "AD" form-factor PHBG (clamp-type fitting an right hand mixture screws) carb body that has a four-stroke atomizer and needle seat. The other point is to use a throttle slide that doesn't generate too much vacuum at idle. The Pinasco comes with a #30 slide. I feel that a #40 slide is more appropriate.

I bought extra pilot jets and idle jets so I can fine-tune the carb for a Stella 4T. I hope to set it up before Amerivespa, but depending on how long it takes for a stator for his bike to come in, it might be done after Amerivespa.