Blue C3

[bbrins]

Another member who also has a C3 thinks that I should start a build thread. I'm not real sure that I would consider this much of a "build", but maybe more of a status thread. I'm not really planning on going hog wild with this scooter, it will most likely stay 49cc, but I do have a few mild upgrades, personalization, maintenance, etc. planned for it.

Anyway, my scoot is a 2007 Yamaha C3 that I purchased new in the fall of 2007. I didn't really ride it much over the last 10 years, other than exercising it once a month or whatever, it only has a little over 1200 miles on it.

Here is what I am starting with...

[Happypancake!]

Welcome!!! Join the ride game

49ccscoot.proboards.com/thread/561/scoot-tag-game-2018-champ?page=128

You can see the build links on the PC version.

[bbrins]

Today, I cracked open the variator cover and found quite a bit of belt dust. I was figuring on replacing the belt anyway since it is over ten years old. While I was in there, I cleaned everything up, replaced the belt, greased the secondary sheave according to the service manual, removed the restrictor washer, and put in a set of Dr. Pulley 5 gram slider weights. I noticed that the outer edges of the front pulley halves were kind of rough and sharp, so I knocked that down with some real fine sandpaper and a scotchbrite pad. I took a stab in the dark with the 5 gram sliders, I'll see how they do as they break in, and probably experiment some more with it later.

I gained about 3 Mph for a new top speed of 43.2 according to my GPS. Actually, I got it up to 45.9 with a good downhill run, but had to let up for a curve. I don't think I hit the rev limiter for either of those, I used to be riding the rev limiter at just a little over 40 mph. It would be nice to see a bit more oomph in the middle of the range.

I can never seem to remember to take pictures as I am doing things, so this is a bit light on detail.

Getting ready to take the clutch assembly apart, I kept envisioning a foot slipping off and having the clutch hit me in the face 🤕...


Got rid of the restrictor washer...


Everything reassembled and torqued to spec, left the cover off for the test ride...


Dammit, I forgot that those locating pins were still in there when I went or the test ride and lost one.

[Happypancake!]

Watch out when torquing down the variator w/ the washer removed as you can mess up the crank splines. I move the washer to the outside just under the nut to prevent this.

Pull off the metal grid of the air filter. It will give it a bit more.

GET a tach. I makes tuning easier.

When u can, GET rid of the  knobby tires, I put Michelin Boppers on  130/90 rear.  45 psig.

[bbrins]

Thanks. I'm going back out there right now and put the washer behind the nut before I forget about it. The air filter is one of the things on my short list, was kind of thinking that the metal screen didn't need to be there. Will look into getting a tach, need to study up some more on variator and clutch tuning before I go any farther on that front.

Yeah, I've been watching the scoot tag thread. Went out to try for the tow truck one after I buttoned everything up, and couldn't find a danged tow truck.

[Happypancake!]

Rev limiter is at 9200 rpm. I'm max'd @ 48mph @ 9200 rpm.

[bbrins]

Okay, I guess I'm back. Shortly after my last post, my C3 died on me several miles from home, I figured out that the issue was that the fuel pump wasn't running. You know it is amazing how many people have asked me to help them move or haul stuff for them, sometimes at just a moment's notice. I called probably a dozen people that either had a pickup truck, or that knew how to drive stick so they could bring me mine, I'll just sum it up to say that I wound up pushing that little effer all the way home. It got parked in a corner of the garage until last weekend.

Anyway, I have now replaced the fuel pump and rubber gasket and it runs. I've been cleaning it up, and am now waiting on a set of new tires to show up, I'm not even going to take it around the block on 15 year old tires. After that, I'll work on tuning the variator.

I'm kind of thinking about a big bore kit. Is 45-50 mph and a bit more grunt in the hills asking too much of this engine? Anyone know a kit that comes with everything I need, any brands to stay away from? I'm going to do some studying on this to decide if I really want to do this. It's one thing to play around with clutches and variators, probably not going to do any catastrophic damage, but a bbk could wind up with a grenaded engine. Is the kit that Rolling Wrench offers with the tuner any good?

FWIW, I'm under no illusions that this will ever be a powerhouse, I'll get out of it what I can get out of it and be okay with it.

Edited to add:  I'm aware that there was a recall on the fuel pump gasket, in around 2010 or 12, the local(not really) dealer checked and said it was taken care of.

Edited again to correctly spell "edited".

[bbrins]

Got everything buttoned up from the fuel pump replacement, got the tub, seat, and all of the panels back on.

Replaced the original Cheng Shin tires, with a pair of Shinko SR426's. I kinda started to regret my choice of tire after getting the new rear tire mounted to the rim. Compared to the originals, these are even knobbier. I'm going to leave these on there for now and start searching for something better for the street, at least I have fresh tires. I originally tried to find a pair of Michelin Boppers, but apparently they have been discontinued, at least in the U.S. As far as balancing was concerned, the rear needed nothing, I fiddled with it for 15 minutes trying to find a heavy spot and couldn't detect one. The front needed about an ounce of weights, that was the best I could get it after repeatedly breaking the bead and turning the tire a bit. I don't care for the look of the stick on weights, so I think I'll try and get some Dyna Beads, or whatever those ceramic balancing beads are called. I also installed a fresh battery, although the old one seems to be holding a charge, I'm not sure I trust it.

[aeroxbud]

We can still get the boppers here in your size. But it looks like your right. Everywhere I have found them in the U.S. Is discontinued.
But scooter tuning.ca have them in stock. Quick delivery and no more on shipping than from the U.S. www.scootertuning.ca/en/wheels-tires-tires/38051-tyre-michelin-booper.html?search_query=Tire+Michelin+Bopper&results=1

[bbrins]

Oh my. Is that the going rate for Boppers these days? When I looked at various sites here in the U.S., they were around $60ish, but then those prices might not be up to date, being as they are discontinued and not in stock. I may buy them at that price anyway, but I think I'll shop around for something a tad more economical, but still good quality? Thanks for the link.

[bbrins]

Screw it, it's only money, I still had my tax returns burning a hole in my pocket. I went ahead and ordered the tires, ordered a Malossi 70cc big bore kit while I was there. I got the Malossi over the Rolling Wrench one because of the tuner. The Malossi appears to be more idiot proof with preset tunes, but still some adjustability, and it only raises the rev limiter something like 1200 rpms, so I can't get too carried away. I need to order a new set of roller weights since the variator that comes with the kit uses a larger size.

[geoffh]

Strange I see no mention of the exhaust,a stealth exhaust adds quite a bit of umph over a standard Yamaha,the wild lion is Zino,s go to pipe.

Geoff

Oh I nearly forgot that air gun I see in your garage !!! smashing for wheels and truck,s scoots need a little more finess we have to many stripped cranks to list thanks to those beasts.

[bbrins]

I only use the impact for disassembly, and only on the middle setting(or lower) for something small like a scooter, if it needs more oomph than that, I use hand tools. I do use it some for assembly too, but only after starting fasteners by hand, and then just use it to run it down to snug something up while holding things together with my other hand, not torquing anything down with it, on a scooter anyway. On something like a scooter, I'm only using it to remove things like a variator nut, clutch nut, for removing wheels, things with larger hardware. I wouldn't dare use it on some of the other bitty hardware holding these things together. If your stripping crank threads on disassembly, it's most likely from someone hamfisting the previous assembly, probably from cranking crap down with an air gun, or just over-torquing with hand tools and galling the threads.

[bbrins]

Got any recommendations for an exhaust? I'd prefer to keep the modifications somewhat incognito, so as not to draw too much unwanted attention. A big shiny loud chrome exhaust ain't gonna happen, but something more low key, not particularly obnoxious, and looks somewhat like it could be stockish, that I might go for.

Edit: actually, I just realized that you made a recommendation, I will look into that.  Thanks.

Edit #2:  Malossi doesn't appear to list any exhausts for the C3, am I missing something?  Checked under the 4 stroke Zuma as well, nothing there either.

[aeroxbud]

Jun 5, 2022 11:17:00 GMT -5 bbrins said:

Got any recommendations for an exhaust? I'd prefer to keep the modifications somewhat incognito, so as not to draw too much unwanted attention. A big shiny loud chrome exhaust ain't gonna happen, but something more low key, not particularly obnoxious, and looks somewhat like it could be stockish, that I might go for.

Edit: actually, I just realized that you made a recommendation, I will look into that.  Thanks.

Edit #2:  Malossi doesn't appear to list any exhausts for the C3, am I missing something?  Checked under the 4 stroke Zuma as well, nothing there either.

I don't think geoffh realised it's a four stroke. Not so much gains to be had with the four stroke stuff. It's more about the sound than performance why people usually change them.