Yuminashi 175cc BBK

[JaeMelo]

Anyone plan on getting or already have the new 175cc BBK from Yuminashi?!

Block
Head

[BPT7594]

Had a 175cc kit with 150 Head, not enough money for the bigger head.
I try to be as conservative as possible but the power is amazing. Bigger valves are long overdue. With the 150 head the gasket is thicker too, compression drops a bit (safer) and the meat of the gasket is thicker.
In my view, they nailed it with this setup. The bigger head has potential, but I have not tested it yet so I cannot say for sure. But the 175cc for the 150 head is doing great over here with 35mm throttle body and a fuel controller. I will dyno it after we breaking in but the 164cc kit with stock head and Yuminashi cam makes 13.5HP so this may be 15 at least.

[lolofigo]

Had a 175cc kit with 150 Head, not enough money for the bigger head.
I try to be as conservative as possible but the power is amazing. Bigger valves are long overdue. With the 150 head the gasket is thicker too, compression drops a bit (safer) and the meat of the gasket is thicker.
In my view, they nailed it with this setup. The bigger head has potential, but I have not tested it yet so I cannot say for sure. But the 175cc for the 150 head is doing great over here with 35mm throttle body and a fuel controller. I will dyno it after we breaking in but the 164cc kit with stock head and Yuminashi cam makes 13.5HP so this may be 15 at least.

What is dyno difference between 164 kit with and without fuel controller on stock head? I'm considering getting fuel controller to cure overheating problems on full throttle. Maybe changing to bigger head would a better idea?

Sent from my SM-N9005 using Tapatalk

[Sam]

My bike did around 13 hp with take 170 kit with stock fuel
Just reveived the 31mm tb
Fro yumi
So i think should go up to 15 hp
Will let know after dyno

[BPT7594]

Had a 175cc kit with 150 Head, not enough money for the bigger head.
I try to be as conservative as possible but the power is amazing. Bigger valves are long overdue. With the 150 head the gasket is thicker too, compression drops a bit (safer) and the meat of the gasket is thicker.
In my view, they nailed it with this setup. The bigger head has potential, but I have not tested it yet so I cannot say for sure. But the 175cc for the 150 head is doing great over here with 35mm throttle body and a fuel controller. I will dyno it after we breaking in but the 164cc kit with stock head and Yuminashi cam makes 13.5HP so this may be 15 at least.

What is dyno difference between 164 kit with and without fuel controller on stock head? I'm considering getting fuel controller to cure overheating problems on full throttle. Maybe changing to bigger head would a better idea?

Sent from my SM-N9005 using Tapatalk

Fuel controller has little effects on HP. It helps perfect the AFR. Which will eliminate hot running engine.
If you frequently have to see the hot light I suggest getting the controller and richen the mixture at high rpm. 12.6 is max.

[JaeMelo]

My bike did around 13 hp with take 170 kit with stock fuel
Just reveived the 31mm tb
Fro yumi
So i think should go up to 15 hp
Will let know after dyno

I hope you have the manifold and matching injector also. The throttle body alone won't do much good for you if you do not have the necessary hardware to mount it. Especially regarding the fuel needed to take advantage of the increased airflow.

If you really want to see a bump in HP make sure your bike is running where it makes its peak HP... just north of 8k rpm if I recall.

All I have on my bike is the:
Tsukigi RRGS Exhaust => Here
Yumi 164cc kit
Yumi 150cc head
Yumi 31mm throttlebody
Yumi Type B 6 Hole light bore fuel injector
Yumi Type B Manifold
Yumi Variator
8gram rollers and can still hit 120km/h or 74mph with stock gearwheels all while getting up to speed very quickly thanks to the light rollers.

When I use to run 12grams the bike was pretty slow imo but as soon as I lightened up the rollers to 3x 10g's and 3x 8g's I noticed a huge bump in power. Doing all 6 rollers at 8g's somehow made it even easier to get past 110km/h right up onto 120km/h.

[chicaboo]

All I have on my bike is the:
Tsukigi RRGS Exhaust => Here

I've always wondered about that exhaust. Is it much freer flowing than a stock exhaust with a cat?

[chicaboo]

If it sounds anything like it does on this Click 125, I'd be wrapped.

[Oyabun]

Gav, I brought one of those home in my suitcase last time when I was in Indonesia. It is a straight through flowing end can , unlike the stock multiple canister setup. However reality is different from the marketing pictures. I guess, you get what you pay for. The build quality is definitely not par with the other aftermarket ones.
Remind me if I'd forget, I'll try to make a few real life pictures of the one on my shelf.

[chicaboo]

Gav, I brought one of those home in my suitcase last time when I was in Indonesia. It is a straight through flowing end can , unlike the stock multiple canister setup. However reality is different from the marketing pictures. I guess, you get what you pay for. The build quality is definitely not par with the other aftermarket ones.
Remind me if I'd forget, I'll try to make a few real life pictures of the one on my shelf.

Since the can is under the plastic heatshield, If the s/s manifold looks reasonable, I think it would be OK.
My only concern would be is there anywhere decent to weld a WB O2 bung on it with those long springs...?

[JaeMelo]

If it sounds anything like it does on this Click 125, I'd be wrapped.

That video is an absolute understatement lol. It sounds even better and more aggressive then that in person. They even include a baffle that quietens the exhaust down like how you hear in that exact video. However once you remove it, that along with the a higher a revving motor due to lighter rollers gives a sound I just can't explain with words.. All I can say mate is that the exhaust comes out to be $50 USD and is absolutely worth it. I've already purchased another because I'll be installing an AEM WideBand O2 sensor bong on the down pipe like the one in my car. I have pictures of the second one and can say for sure the build quality isn't bad at all. Its not perfect but for the price if you do go for it you see it worth every penny.

I'll try to get a video up but in the mean time I can say it sounds more like in the one in the video below... (2:38 - 2:50)

[JaeMelo]

Gav, I brought one of those home in my suitcase last time when I was in Indonesia. It is a straight through flowing end can , unlike the stock multiple canister setup. However reality is different from the marketing pictures. I guess, you get what you pay for. The build quality is definitely not par with the other aftermarket ones.
Remind me if I'd forget, I'll try to make a few real life pictures of the one on my shelf.

You did not get this exhaust then haha. I have 2 of them an they look exactly like in the picture down to the T.

[chicaboo]

That video is an absolute understatement lol. It sounds even better and more aggressive then that in person. They even include a baffle that quietens the exhaust down like how you hear in that exact video. However once you remove it, that along with the a higher a revving motor due to lighter rollers gives a sound I just can't explain with words.. All I can say mate is that the exhaust comes out to be $50 USD and is absolutely worth it. I've already purchased another because I'll be installing an AEM WideBand O2 sensor bong on the down pipe like the one in my car. I have pictures of the second one and can say for sure the build quality isn't bad at all. Its not perfect but for the price if you do go for it you see it worth every penny.

I'll try to get a video up but in the mean time I can say it sounds more like in the one in the video below... (2:38 - 2:50)

There's too much other "noise" in that video for me to appreciate the sound of the exhaust.
But I really dig the way it sounds in the video I posted, even if it does have the baffle in.

I leave the baffle in my exhaust, and it is several times louder than the video I posted.
If I took my baffle out it would damage my hearing (more than it is) over time...

I don't know what the shipping is to Aus, but I may get one of these for when the cops defect my scoot for being too loud...

Any chance you could post a video of yours with and without the baffle?

[BPT7594]

I put a forza 300 muffler on my 61mm pcx. Can't hear the exhaust over 30km/h. Power is great.
Only problem is you'll have to make patches and pipe

[Oyabun]

Jaemelo: I'm pretty sure I've got the same exhaust. And from the same distance it looks exactly the same as the one on the pictures. However there are things which are not visible on the picture. The clamp to fix the pipe to the exhaust port is mild steel welded to a stainless pipe, and the cutout is mediocre re at a bare minimum. The welds are definitely not up to the level of a brand name aftermarket exhaust. The stepped part of the pipe before the can is looking great, but in reality the sliced and steped part is only welded on top of the same diameter pipe as the first elbow part. The end can looks OK, but it is made out of mild steel and has all kinds of unfinished - like stuff like not treated cut edges and so.
All I'm saying is that one gets what one pays for. It is certainly more than what I'd get for 50 usd plus shipping here - or in other words worths more than 1/6th of a Yoshimura.

[JaeMelo]

^Ehh just to make sure your exhaust looks exactly like this and says RRGS on the top?! The only reason I ask is because a few of the points you made I am having a hard time seeing on my own. Specifically where you mentioned "but in reality the sliced and steped part is only welded on top of the same diameter pipe as the first elbow part". I can however agree on the welds not being absolutely perfect. However I have a hard time even regarding that as "a thing" seeing that the bike's side stand and main stand welds look the exact same; even some parts on the frame.