Yuminashi variator and belt

[wingz]

Just as you said... Your opinion. Most exhausts don't add power, there are probably three of four that actually do and those add .75 to 1.5 hp at redline!!! Just like building a hotrod you need to match parts to make it worth your while. With my mods I have increased my top speed by 19%, average economy by 17.3% and increased my riding pleasure. What part of that was a waste? I've added a quiet performance exhaust, replaced the intake back to the throttle body for a .25" larger tube and come filter in the air box, swapped the belt and variator myself (15 minutes start to finish ), added a givi short screen and added soft sodded saddle bags. I get 88mpg and have the ability to hit 81mph.

I love that! If I want to carve corners or go fast I have a modified Porsche 944 (internal engine work and koni's) in the garage and a daily driver for hauling around the family. Heck I have a Honda Spree when I want to put around too. To each his own, let's not discourage others from modifying their toys the way they want.

Hi Mgalutia88,

I think you have done very well.
As I read it the only change that affects gearing is the variator and belt.
Is that responsible for 20% increase in max gearing?
Can you please confirm if 81mph is verified by GPS. If so, that would be a 14% improvement for me since my top speed is 71mph (gps). (although your previous belt may have been worn)
That is a little better than the 12.8% I could get with the Yuminashi gear set. Anyway, just thinking it through thoroughly before spending more money.

[Mgalutia88]

Wingz, I was unable to verify a top speed run yesterday as I have to hold my gps in my hand to watch the speed. I was able to verify that my speedo is dead on up to 50mph by holding and watching it. I updated my gps software last night so it will record top speed so now I can stick it in my pocket and go and check after the fact. I won't be riding this morning as it is currently 21 degrees F, I will this afternoon however.

Yesterday I did hit an unverified 78mph on flat ground. My top speed had been 81 on the stand and 79 down hill but I've changed the intake this week so it remains to be seen if I can hit the rev limiter now or not.

On a separate note I'm debating between new rear shocks and a high gear kit. (You know it never stops )

[dasshreddar]

Gear kit also how fast are you trying to go? Time to get a big bore kit ,
But getting good 150 parts in the US sucks...

[Mgalutia88]

I'm thinking I'm going to "try" a set of the RFY shocks from eBay and see what happens. I guess the worst case scans rio is that they don't fit! They sell for roughly $70 a pair plus $20 to ship

[Mgalutia88]

Well yesterday I had a verified 70mph which matched the speedometer. Today we've had wind gusts in the 30mph range and steady winds in the 15-20mph range. I've been riding but it hasn't been all that pleasant.

Dasshredder, I'm not really interested in a bbk at this time. I'm more interested in a 31mn tb and larger injector. I'm just not interested in the $300-$400 it's going to cost at the moment. I think next will be shocks, kitaco gear kit, and different tires.

[dasshreddar]

Well yesterday I had a verified 70mph which matched the speedometer. Today we've had wind gusts in the 30mph range and steady winds in the 15-20mph range. I've been riding but it hasn't been all that pleasant.

Dasshredder, I'm not really interested in a bbk at this time. I'm more interested in a 31mn tb and larger injector. I'm just not interested in the $300-$400 it's going to cost at the moment. I think next will be shocks, kitaco gear kit, and different tires.

Get the tb and injector first(I want those too), I've been saving $ for more hp (but I don't like being the guinea pig )
I would definitely recommend trying a taller tire before buying a gear kit.

[wingz]

I would definitely recommend trying a taller tire before buying a gear kit.

While that is much easier and has other benefits (and I am likely to do it myself), the 140/70-14 only provides 3% higher gearing over stock tyre.
That would increase my top speed from 113km/h to a whopping 116.4km/h.

[waspmike]

Difference between a Michelin and IRC on a 125 ESP on the flat is about 7-8 kph. depending on rider weight. Downhill only about 3 kph.

[Mgalutia88]

Tb and injector will come later on. In the ran time I'm goin to put off the RFY shocks for a kn planning torque driver, chameleon factory contra spring bearing and an oil catch can. I also have a spare air filter cover that I think I'm going to hack up a bit to enlarge the opening since I have a 20% larger intake now. The setup I used replaced the standard 1-1/4" intake tube for 1-1/2" tubing and a K&N r-1100 with the dry wrap instead of oiling the filter. I got the filter for $25 on amazon and the dry wrap for another $13. Free shipping on both.

The intake makes a load of difference with hill climbing. Now my issue is the flat spot between 50-65mph when accelerating up from cruising at that speed. I'm going to see what happens with the torque cam.

Webike sells the on planning torque cam for $56 plus another $25-30 shipping to the US.

[dasshreddar]

I would definitely recommend trying a taller tire before buying a gear kit.

While that is much easier and has other benefits (and I am likely to do it myself), the 140/70-14 only provides 3% higher gearing over stock tyre.
That would increase my top speed from 113km/h to a whopping 116.4km/h.

my calculations say 4mph(my tire) is 6.4kmh, but whatever...
I think mgalutia has enough "trans" and should focus on "engine" now.
If he can do 81 already, with my size tire he can do 85, + a gear kit =?mph... unless he needs ludicrous speed for downhill only, then that is ok

[Mgalutia88]

Personally, I had issues with belt shutter at take off on my 150 with their variator. Then the facing started chunking off of the driven face. I also have their Contra spring installed and all of the powder coat has flaked off within 1000 miles. I won't be purchasing any more of their parts. I tried six times emailing Reggie to multiple email addresses and his Facebook page to ask about the cylinder bore's in his big bore kit's. He refused to respond. I can ask questions about anything else but the half-dozen times I've messaged over six months I get ignored.

In general yuminashi parts are nothing more then machined and reworked factory pieces. RZ racing is using proper coatings and Takegawa has great parts however.

[Mgalutia88]

To those that have good luck with yuminashi good for you. There are many people including on the grom forum that have had issues with yuminashi. Including some bore and piston sets that did not match and caused engine failures.

I requested information on a 175 cc yuminashi big bore kit from PCX racing in France. Keep in mind that PCX racing sells the 164 cc bore kit. I was told that PCX racing will not sell the 175 kit because of poor quality. What does that tell you when their distributors will not sell some of their parts...

[Mgalutia88]

I think they are just hit and miss

[Mgalutia88]

I have had issues with the face cracking off of this variator.

[Pcxdemon]

I have had issues with the face cracking off of this variator.

Mike can you take some photos of that and post it here? Id like to see that..
Thanks

[Mgalutia88]

I'll try to tomorrow morning Vlad. We just moved and the bike and all my parts and tools are in the old garage. I found that the yuminashi variator and the daytona variator have the same top speed on the stand so I just quit with the yuminashi piece. The multi angle drive face also dropped rpms significantly and caused WAY slower acceleration than with the Daytona, even with using 9g weights. I just didn't feel right.

By the way my Takegawa cam is in time now and the bike is going back together!!

[mikelx5]

also if you use the yuminashi vario do not use sliders it will snap belts

[Pcxdemon]

also if you use the yuminashi vario do not use sliders it will snap belts

Fair enough..how do you know that would happen though?

[mikelx5]

ive snapped 3 in less than 2000 miles

[Pcxdemon]

What belts were you kept using?