2005 Yamaha Zuma (Bws 50) build

[Jwhood]

Jun 9, 2019 10:43:33 GMT -5 mattyslimz said:

Jwhood did you see any loss in performance with the cooler one? I’ve noticed these iridium plugs are much easier to foul. All the jetting and mixture must be right before putting in one of these $10 plugs.

No difference in performance just temp change bro

[mattyslimz]

I put some decals on from DecalDino. I figured it would go good with the black and gold that seems to be everywhere else. I may have to reorder a set because I’m horrible at installing “stickers” but who isn’t? unless your a tint/car wrapper guy. The left side looks good where it’s supposed to be, so I’ll probably just re-install the right side. Right side I folded over part of where the “M” is on accident and have the the whole decal too low. They’re only $25 bucks and these seem like very high quality cuts. I’ll take my time on the next set..

[mattyslimz]

I was going to create a new thread titled “Air cooled monster” but forgot I already started one for this bike. I must of fell and bumped my head because I went and spent more than I should but cheap thrills aren’t my thing and I wanna have fun.

The original crank and bearings were already making a little bit of noise upon purchase, but as time went on the noise only progressed and got worse. I searched what would happen if I just kept riding on a bad crank and the results weren’t good, I’ve read everything from seizure from the crank (NOT piston) to also case damage. It was enough for me to go ahead and get some parts ready for a rebuild. I wanted more power and decent reliability, I’m not dailying the bike to work or anything but would like to take it once or twice to week to save money on parking. Parking spots in the Washington DC metro area where I work can get up to $18 a day sometimes so this is a no brainer that I will alternate between my QJ RX8 and this one for parking savings. 
Heres a list:
1. Malossi RHQ 12mm crank
2. Stage 6 MKII 12mm Racing 70cc kit
3. C4 Stage 6/SKF bearing and seal kit


Parts needed to do the work 
1. Easyboost crank splitter/bearing separater combo tool
2. Easyboost flywheel puller Minerelli 
3. Large size oil filter strap
4. Mapp gas torch. 
5. My kitchen freezer.


I also am removing the oil pump and going premix. Parts purchased for that I’m still waiting for:
1. Doppler oil pump block off kit
2. A non-vacuum fuel petcock from Yamaha part# ya-2gu-24500-02-00-1




Here is how far I’am.. I have a ways to go yet, so expect me checking back in frequently for questions and updates. 

[mattyslimz]

With my very improvised work area and a few curse words later I managed to get the crank out and case split. Patience is key when doing this, maybe playing Cannibal Corpse, Morbid Angel, Five Finger death punch and some early Dave Mustaine (Megadeth) on my Bluetooth speaker didn’t help but the case splitter/bearing puller from EZBoost worked very well!

The main bearing in the crank felt rough. I was lied to thinking this was a single ring piston from Athena. Turns out it was just a simple NCY kit, (Senchen). I really don’t know how this thing felt so powerful though. I must not have ridden a real fast scoot before. Maybe it’s just that the gears are so short in this thing that it seems like it has big power like a midrace.











I’am now on my way to Home Depot to pick up a Dremel and carbide bits to attempt some minor case trenching/porting. I’m watching one of Brent (90GTVert’s) latest vids “Port Matching, Porting and Trenching Two-stroke engine cases” I plan on being VERY careful not to go too deep. I also believe leaving the porting work you do slightly rough for a better charge/mixture as opposed to very smooth, I’m just wanting to get it a little wider. I just need to do some fine cleaning to the halves now. The ol’ lady is gonna kill me if I get this dining room table too dirty. My mapp gas torch worked great for getting the bearings onto the crank, now everything’s back in the freezer waiting for install. I chose Hondabond HT because I see that’s what a lot of scooter enthusiasts recommend and I’ve used it before changing the valve cover gasket on an old Accord I had. I used the rest I had on the install of the Streetrace kit on QJRX8, so I have a fresh tube.

[aeroxbud]

This thing is going to fly. I had the stage 6 racing LC in the Aerox. It love to rev, and pull hard.
What carb, and exhaust are you going to use?

[mattyslimz]

aeroxbud, Stage 6 24 PWK. Any suggestions on filter for this thing? I was thinking modified stock airbox but than I’d need an adapter probably. C16. I’m going to run the ZX at first to see how it goes, I’ll be ordering a pipe this week. Any other suggestions on pipe and or filter style is open ears on this end.

[aeroxbud]

I had a 24mm carb on mine, with a Yasuni C16 and foam filter. Not keen on that type of filter. But it's just easier fitment wise. And the Aerox was not a daily rider.

[mattyslimz]

I have my marks ready for cutting/trenching. I don’t plan on doing anymore than just this area. Luckily behind just these areas is a thick cast webbing so no back filler such as J-B Weld is necessary. It will be similar to the way the Vino 5BM case’s nice straight path is. I may slightly round off a couple sharp edges not marked, but I don’t want to push my luck. Brent’s (90GTVert) video helped immensely while trying to figure out what I needed. I also searched some 2-stroke trenching photos on google as per referenced in his video.

[mattyslimz]

Cases trenched, now what?









Now comes the most stressful part re-marriage of the cases. I took the hole wall off that was blocking the transfer/boost ports, I didn’t go to deep even though I went ahead and used Marine J-B Weld on the rear near the webbing casting. The Marine version of the JB Weld has a higher temp rating and a higher tensile strength, it is also resistant to petroleum.I left the cuts a little rough for a better mixture charge.

[mattyslimz]

A goodie box came in today. It entailed..
1. Stage 6 R/T PWK 24mm 
2.Polini 360 Minerelli Horz. intake 26-28-30 VHST/PWK
3. Top Performance Vforce3 carbon reeds
4. Malossi E13 filter 48-52mm
5. Stage 6 PWK Main Jets 125-148

I went with the TPR version of the Vforce3 reeds because I read somewhere that the S6 version didn’t have real carbon fiber petals and that they chipped and/or disintegrated easier. Not sure about any truth in those findings, but the actual original Moto Tassinari vforce’s for Zuma we’re too expensive ($148) and these look to be just as good. My only other experience with aftermarket reeds was with my old Yamaha Blaster that had Boyesen power reeds installed by the previous owner and I never took the bike apart that far, but it was quick.

This carb from Stage 6 looks to be very nice. The fit and finish looks better than the OKOs I’ve seen in person at a local moped shop. Why do they have such long lines for the 2 vents if these carbs are made specifically for scoots?  Looks like they’ll have to be trimmed or replaced with 90 degree short tubing or else they’re going to drag the ground! My fingers are crossed this thing isn’t a hassle to get tuned in right. The humidity is starting to fade it seems here in the region and I think we’ve made it through our hottest days, otherwise I may need to hide the keys for the home defense safe to keep me from offing myself getting this carb/setup dialed.

aeroxbud says he ran almost an identical setup only in LC version using a 24mm and a foam filter. I know no 2 bikes will ever have the exact same setting up, but a ballpark figure would really ease my mind. 

[PIG]

I’ve never used a 24 mm pwk, just 28mm and bigger. But my Prebug with a 28mm PWK, MXS 70 race and S6 R1400 runs a 50 pilot jet and a 150 main jet with the needle on the middle clip.

Also the c16 is an amazing all around pipe, probably the best. But if you really want to rip, throw a C21 on it. That’s what I would do anyways. 20 bucks says you’ll ride it for a month and then want more. Skip the mid race step and just do what I’m sure your thinking about anyways lol.

[aeroxbud]

It was about 8 years ago I ran that set-up. Was trying lots of cylinders at the time. But I think it was about 140. I would probably start at 160 to be sure.

[mattyslimz]

Aug 12, 2019 23:26:35 GMT -5 PIG said:

I’ve never used a 24 mm pwk, just 28mm and bigger. But my Prebug with a 28mm PWK, MXS 70 race and S6 R1400 runs a 50 pilot jet and a 150 main jet with the needle on the middle clip.

Also the c16 is an amazing all around pipe, probably the best. But if you really want to rip, throw a C21 on it. That’s what I would do anyways. 20 bucks says you’ll ride it for a month and then want more. Skip the mid race step and just do what I’m sure your thinking about anyways lol.

Cool, appreciated. I took your advice and went ahead with a C20. The C20 is a little shorter and apparently that will keep the powerband a little wider mid to high as opposed to the C21 that’s similar to the R-1200/1400 with its explosive powerband engagement that kicks in way up top. Hopefully this was the proper choice. The C20 will rev out a little higher than the C16 also which is good.
I’m going to need an inner rotor ignition that will accept a fan and still haven’t made a choice on that..

[mattyslimz]

If anyone knows what all I need to correctly install and mount this pipe to this style Zuma it’d be a big help. I guess c16/20/21 all use the same flange, someone here must be running one of the three on a bugeye, I just don’t know if everything will come in the box I get. ryan_ott?
There’s a riser on my shock so the bike is opposite of lowered. The Leo Vince has a couple battle gashes but it hasn’t happened since the riser install and from what I gather it will help with the Yasuni fitment because it looks like C series pipes hang a little low..

I have everything buttoned up. I kicked it over a couple times and it started right up. The manual fuel cock has much better fuel flow. Just need to do a leakdown test before I even attempt at any testing/tuning or riding for that matter.

On a side note this was a waste of $15.. what the hell did I put that in there for? I had to grind out material just to make it fit (they did mention for the vertical first in the description). I guess it’ll divert airflow way from back in that stator area.

[190mech]

Everything needed will come with the pipe!