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 YAMAHA ZUMA BUGEYE - top performance 70cc kit questions. 
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Scooterologist

Joined: Sun May 07, 2017 9:55 am
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Post YAMAHA ZUMA BUGEYE - top performance 70cc kit questions.
My Top performance kit came in today! Trophy Black edition I think it looks good was hoping to get some input from you guys. I know this is a great kit and is reliable. That is why I choose it. My friend had an Athena and had some issues but he may have set it up wrong. I liked how you don't have to change the rings very often.

I also ordered a Polini hi speed variator kit and that came as well. It came with the variator, clutch springs, contra spring, Evo slider that prevents the torque spring from moving I guess, and rollers. It was cheaper than the Malossi variator so I decided to try it. I like that it came with the clutch springs. I used one on my Prebug and was very happy with the improvement.

I also picked up some carbon fiber reeds that said Athena and fit stock intake manifold.
All parts from Scootuning.Ca very impressed with them it was free shipping and It totaled around $220 USD. I also received it in 3 days.

I am waiting on my connecting rod bearing to come in from the Yamaha dealer should be here next week. I also ordered the number 84 jet OEM.

I have a couple questions hopefully you guys can help me out.

I have been reading all winter and am feeling confident about the install but, I was wondering which way the head gasket faces? The ribbed side towards the head or towards the cylinder and if the base gasket has one which way for that as well?
There was another post about this but, the guy didn't comment back which way he ended up doing it to confirm.
Is there anything else that I am missing?
70cc kit TPB
2 stroke oil ( any suggestions? I am going to Walmart, auto zone, or O Riley's)
Bearing from factory
Jets
New spark plug the one recommended in the instructions.
Carbon Fiber Reeds

What kind of file should be used to chamber the ports and is it just a mild scrapping? The ports don't have any thing that sticks out but they see pretty sharp that's why I ask. Also what is a good solvent to wash the cylinder in I have heard some people say water and soap and other say WD40 are there any other ones to use?

Any other last minute tips would be appreciated!
Thanks Again I can't wait to get this baby on there!

I tried to upload the pics but says file is to large.


Fri Mar 16, 2018 2:26 pm
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Post Re: 70cc kit Top Performance on 2008
Ridge goes up on head gasket if you use one at all
I have been using copper permeated

Every base gasket I have ever seen was flat no ridge but it would be ridge up
Oil high quality full synthetic
Spark plug br8hs
Clean with soap and water dry and oil
File what ever fine file will fit in the bore without damaging it try the model section at hobby lobby

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2008 zuma dual headlight mod koso mirrors liquid cooled polini corsa kit leo vince zx stage 6 variator rally kit custom red paintFUEL INJECTEDsoon to be 100cc
2008 stella olive custom ported 177 cc kit dechromed ford tear drop tail light alive and breathing and awaiting cosmtic surgery thanks to an donkey hind quater hole cager
1985 elite 150 how long can i leave it stock


Mon Mar 19, 2018 4:40 pm
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Scooterologist

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Post Re: 70cc kit Top Performance on 2008
Alright thanks dude!!! :D This forum seems pretty dead so thanks for getting back to me!


Tue Mar 20, 2018 1:06 pm
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Post Re: 70cc kit Top Performance on 2008
I've used Lucas semi synthetic 2 cycle oil from O'Reilly's for over 10,000 miles with no issues.

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Malossi 70cc, 82 main, 46 pilot and needle raised on stock carb, stock exhaust, air cleaner and clutch.


Tue Mar 20, 2018 3:04 pm
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Post Re: 70cc kit Top Performance on 2008
Any progress on the build?


Fri Apr 20, 2018 12:02 pm
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Scooterologist

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Post Re: 70cc kit Top Performance on 2008
Sorry for the delayed response I wasn't sure anyone was even on here seems like a quiet community.

I have installed the new variator kit, so variator new weights polini 6.9 grams, blue contra spring, and the clutch springs. I have hit a top speed of 53 gps in my Samsung. I did have some help from the wind though :). Otherwise it's cruising at about 47-49 most days. My jetting is a little off the temperature in michigan is fluctuating so much right now but it seems to run perfect in the mid 50's Fahrenheit. Then once it gets warmer it's to rich.

I have the big bore kit in the house just waiting to install I have been so busy with school and kids I haven't gotten the chance to work on it. Hopefully in the next few weeks I can knock it out.

To anyone that has a 70cc.... Do you premix your oil. I have the top performance kit. I know to change the jet but some video on you tube said if you don't add oil to your gas the kit won't last long.

Any info would be appreciated!!


Sat Apr 21, 2018 7:21 am
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Scooterologist

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Post Re: 70cc kit Top Performance on 2008
Sorry for the delayed response I wasn't sure anyone was even on here seems like a quiet community.

I have installed the new variator kit, so variator new weights polini 6.9 grams, blue contra spring, and the clutch springs. I have hit a top speed of 53 gps in my Samsung. I did have some help from the wind though :). Otherwise it's cruising at about 47-49 most days. My jetting is a little off the temperature in michigan is fluctuating so much right now but it seems to run perfect in the mid 50's Fahrenheit. Then once it gets warmer it's to rich.

I have the big bore kit in the house just waiting to install I have been so busy with school and kids I haven't gotten the chance to work on it. Hopefully in the next few weeks I can knock it out.

To anyone that has a 70cc.... Do you premix your oil. I have the top performance kit. I know to change the jet but some video on you tube said if you don't add oil to your gas the kit won't last long.

Any info would be appreciated!!


Sat Apr 21, 2018 7:21 am
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Post Re: 70cc kit Top Performance on 2008
You were going 47 on a stock cylinder? What else have you done besides the variator kit?

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2008 Yamaha Zuma - Completely stock besides duel headlight
1994 Honda Elite S - Mildly modified


Sun Apr 22, 2018 5:43 pm
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Scooterologist

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Post Re: 70cc kit Top Performance on 2008
I have a Yasuni Z exhaust. Removed the smog box. Throttle mod. I cut holes in my airbox and placed UNI filter vents in. I have 2 holes. It has a 85 main jet in it from team calamari. It runs rich on startup so I let it warm up but I know the top end is rich. I have to mess with the air box depending on the weather I leave tape on it so I can cover the holes if it seems lean and remove the tape if its too rich. I have the new cylinder kit so when I install it I will see the inside of everything and be able to tell how well I managed this lol.

I hit 53 mph the other day believe it or not at least that what my S6 Samsung GPS read. I was going with the wind and drafting behind a car, from a safe distance, but I tuck my body way down so I am as flat as possible. If I sit up I can cruise at 45 mph. I weigh 220 lbs and I am 6 ft 3.

I dont recommend messing with the air box. Once I install my big bore kit I am going to plug them all with tape and just use an OEM 84 main jet.

The polini variator works really nicely and keeps the bike in the power band much better than the stock system. However, I do have a dead zone for the first 5 mph. Its building up revs then it takes off with a lot more acceleration than stock. This dead spot wasn't as bad when I had the stock clutch springs and contra spring. But I have never hit 53 mph before even on its best day with any kind of winds so maybe the stiffer springs helped increase the top speed? I'm not sure still learning. If anyone knows the answer to this I would appreciate it.

All I know is its 70 degrees in MI today so I can not wait to do some riding around town. :cheers: :cheers: :cheers: :rock: :rock: :rock: :hurr: :mario: :hellyeah: :chaps:


Mon Apr 23, 2018 10:26 pm
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Post Re: 70cc kit Top Performance on 2008
Thanks for the reply. I have a pretty much stock 2008 zuma right now. Only thing I did was the throttle mod so I'm going to buy an exhaust and polini variator kit soon.

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2008 Yamaha Zuma - Completely stock besides duel headlight
1994 Honda Elite S - Mildly modified


Tue Apr 24, 2018 5:32 am
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Scooterologist

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Post Re: 70cc kit Top Performance on 2008
Make sure you do your research on the exhaust if I had to go back I would get the Yasuni R I like my z but I eventually got to a point where I wanted to go BBK and I wish I would have gotten a exhaust suited for a Big bore. I think the yasuni z will do fine but the R is designed for a sport 70cc. It can also be used on a 50cc I have read. I picked the Z because I never have to worry about the crank. Highest I have see my tach go is 8600 rpms if down a steep hill which are rare by me its up to 9200 rpm. I can say that Yasuni is great quality comes with bushings for mounting it and overall quality is very nice you can also get them in plain silver and I didn't put the sticker on it so it doesn't look aftermarket. Or maybe it does if the cop is a scoot expert. :haw:

Good luck with your decision!

As far as the polini variator I can't say its better than the Malossi multivar which seems very popular throughout the scoot community. One guy on 49ccscootforums said he had a polini but switched to Malossi and liked it better. I dont have the funds to throw at it to do a comparison. I am however happy with the polini and its a huge improvement over stock. It keeps you in the power band and gives you close to peak HP right when you give it gas. It also doesn't immediately drop revs way down if you let off the gas. In a turn for example you would have to build up revs again with stock but the polini does a nice job of slowing down the revs then right when you go back to full throttle your back to that rpm range where you are making peak power.

It comes with 6.9 grams so I am going to eventually get new weights and do some testing seeing if I get any better performance. :cheers:


Tue Apr 24, 2018 8:00 am
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Scooterologist

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Post Re: 70cc kit Top Performance on 2008
:piss2: on me!!! :doh: :doh: :doh:

I just got home from a 18 hour drive from Florida to Michigan and decided to work on the zuma. Did all the right steps got the rings seated nicely as it went smoothly in to the cylinder. Then I begin tightening the head down to spec. I have a big 3/4 torque wrench but I have the adapters to make the head small. So I am tightening down the nuts in a star pattern I hear one nut click then switch to the next. Nothing kept going thinking this cant be right... but since it clicked for the other nut I figured it was a turn or two away then snap the bolt/stud snapped in half. I guess I will have to go buy a smaller torque wrench not sure why it didn't work on the next nut my only guess is not enough travel for the big wrench.

So if anyone has any input on removing the cylinder stud I would appreciate it.

Also the Top performance head gasket was ribbed and is completely compressed now. Do I need to order another one? If so that is going to suck because I ordered it from overseas. However, I am willing to wait if this means I will get the best seal.

As far as the stud does anyone have any input on installing a new one? I am going to start researching. Hopefully I can get the stud ordered on Monday at my Yamaha dealer then be set back a week in the meantime I can do the reeds and change the main jet.

You know what they say if it can happen it will. Lesson learned. :doh: :doh: Only good thing about this is Im gonna get real comfortable with installing the cylinder. lol :haw:


Fri May 04, 2018 10:38 pm
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Post Re: 70cc kit Top Performance on 2008
I believe that any reducers or extensions actually change the amount of torque at the bolt/nut compared to the calibrated setting in the torque wrench itself.

How did the Polini kit work on the prebug? What other mods did you do to it? I ordered an exhaust and jet kit, but not sure what other way I should go.


Sat May 05, 2018 6:28 am
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Scooterologist

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Post Re: 70cc kit Top Performance on 2008
The Polini was a nice upgrade for the prebug. I changed the clutch springs,weights, and torque spring when I upgraded the variator. It had a stage 6 street exhaust when I bought it off Craigslist I never looked at the jet number so I couldn't tell you what main jet it had.

It had dr pulley sliders in it as well when i bought it I don't know what weight though. That scoot ran great but I had a friend of mine clean the carb for me at one point and he stripped the bolts one the carb so it had a slow leak. It was a 1989 so it was just old and worn I had it for 6 years before I sold it. I was 250lbs at the time so it was a rough ride for me. So I sold it for $800 I only paid $850 for it 6 years earlier so that tells you how well they hold their value.


Sat May 05, 2018 7:41 am
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Post Re: 70cc kit Top Performance on 2008
Thanks, that’ll be my next mod after the exhaust and jets get here.

I know it’s been pretty dead on here, but if you could keep us posted on your build when your studs get in that would be great. So many unfinshed posts.


Sun May 06, 2018 4:12 am
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