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Discussion Starter · #1 ·
I recently bought a motomaster 4 piston caliper for my 2012 350 exc, i installed with the stock master cylinder.
To say the least I'm really dissapointed buy the braking. Ive bleed the system 3 times with a vacuum bleeder.
I have to pull the lever almost to the handle bar to do an endo.......the 2 piston stock brembo was better.



Logical sense, brakes would only be as good as the weakest link. So i believe i need a new master cylinder......
I need new lines and a new m/c , i have no idea what i'm looking for, i just want really firm brakes.
Any suggestions appreciated
 

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going way too big there.

the motomaster might have 4 pistons but they're smaller compared to some other calipers. the motomaster MC they sell in a kit with that caliper is only a 13 mm radial unit so you need to look at simular sizes. 19 mm is already way too big and will leave you with a very stiff lever and little feedback.

motomaster say their caliper can work with a stock MC but it still all boils down to the stroke and piston diamater of the MC. stock MC on an EXC is only 9 mm, which might be on the small side.
 

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A 1/2" master from a 450 quad will get you what you want and on the cheap sub $50. 1/2" is 12.7mm perfect for your application and has a micro switch brake light not the junk pressure switches.

Z
 

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That looks like a Warp 9 Wheel + Rotor. I understand people going cheap for the wheels if money is an issue, but first thing I think you should do is unbolt that crappy rotor, toss it in the trash and put something aftermarket and 320mm on it! A Brembo 16x18 master is excellent! I run the Brembo 16x18 with a stock Nissin caliper/pads, Braking rotor, stainless line, Motul RBF-600 and it is excellent. I can lock the front wheel with one finger if I want, or roll endo's all day long.
 

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That looks like a Warp 9 Wheel + Rotor. I understand people going cheap for the wheels if money is an issue, but first thing I think you should do is unbolt that crappy rotor, toss it in the trash and put something aftermarket and 320mm on it! A Brembo 16x18 master is excellent! I run the Brembo 16x18 with a stock Nissin caliper/pads, Braking rotor, stainless line, Motul RBF-600 and it is excellent. I can lock the front wheel with one finger if I want, or roll endo's all day long.
Looks like an aftermarket 320mm brake rotor to me. What is throwing that rotor in the trash gonna solve? :headscrat

BTW, I have heard great things about Honda brakes (master cylinder wise).
 

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Looks like an aftermarket 320mm brake rotor to me. What is throwing that rotor in the trash gonna solve? :headscrat

BTW, I have heard great things about Honda brakes (master cylinder wise).
I wouldn't bet your peanuts on it. The wave pattern is identical to the Warp 9 setup. And throwing it in the trash would solve his brake problems.
 

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So warp9 comes oem on which bike?
You must be confused but that does not surprise me given your expertise or lack there of?

The front rotor in the OP's post is Warp 9. My suggestion to him is to replace the Warp 9 Rotor with a "non-budget" (hope this doesn't hurt anyone's feelings?) 320mm brake rotor such as Braking, Moto-Master or EBC unit. The markings on the rotor also show obvious wear/grooving. Please chime in here OP! Hope you get your braking issues sorted out! :thumbup:
 

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You must be confused but that does not surprise me given your expertise or lack there of?

The front rotor in the OP's post is Warp 9. My suggestion to him is to replace the Warp 9 Rotor with a "non-budget" (hope this doesn't hurt anyone's feelings?) 320mm brake rotor such as Braking, Moto-Master or EBC unit. The markings on the rotor also show obvious wear/grooving. Please chime in here OP! Hope you get your braking issues sorted out! :thumbup:
My expertise doesn't consist of throwing money at a problem or "taking it to a shop". I am well aware that the rotor is a Warp9 which would in fact make it aftermarket. I'm also familiar with what brake wear looks like. Thanks for the advice.
 

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But to offer some helpful advice. I had the same issue on my Kawi race bike. The issue was with the calipers which I replaced and whoa, what a difference. You may just have a defective caliper. If the original master cylinder was working prior to the caliper install, I would look into that first. Don't go throwing away your rotor though :lol:, a 320mm piece of metal is gonna have the same characteristics no matter who's name is on it.
 

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Discussion Starter · #16 ·
But to offer some helpful advice. I had the same issue on my Kawi race bike. The issue was with the calipers which I replaced and whoa, what a difference. You may just have a defective caliper. If the original master cylinder was working prior to the caliper install, I would look into that first. Don't go throwing away your rotor though :lol:, a 320mm piece of metal is gonna have the same characteristics no matter who's name is on it.
Before i changed the caliper out, i had the stock 2 piston brembo and m/c. The brakes where rock solid but just was slow at stopping. I changed out the caliper and the lever comes in about 20 mm to the handlebars. So im not sure if i need to keep bleeding ( Ive bleed the system for 3 days) or new m/c. I dont believe its the caliper because as soon at it grips its really quick to stop.
 

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Before i changed the caliper out, i had the stock 2 piston brembo and m/c. The brakes where rock solid but just was slow at stopping. I changed out the caliper and the lever comes in about 20 mm to the handlebars. So im not sure if i need to keep bleeding ( Ive bleed the system for 3 days) or new m/c. I dont believe its the caliper because as soon at it grips its really quick to stop.
How many miles are on the caliper? The vacum bleeders are very effective, so I wouldn't imagine that there is air in the line (assuming if you have a vacum bleeder that you've probably dealt with brake bleeding once or ten times lol). Does the caliper have a warranty? I would bleed my brakes 2 or 3 times before a race weekend and no matter what the brake lever would go all the way to the clip-on. Once I got a few laps in they would firm up a little, but not too much. The bike only had about 1,100 miles when I put it in race trim, so I would hope that they were still within their service life.
 

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Discussion Starter · #18 ·
How many miles are on the caliper? The vacum bleeders are very effective, so I wouldn't imagine that there is air in the line (assuming if you have a vacum bleeder that you've probably dealt with brake bleeding once or ten times lol). Does the caliper have a warranty? I would bleed my brakes 2 or 3 times before a race weekend and no matter what the brake lever would go all the way to the clip-on. Once I got a few laps in they would firm up a little, but not too much. The bike only had about 1,100 miles when I put it in race trim, so I would hope that they were still within their service life.
i have no idea how many miles it has on it at all, looked in good shape and i cant spot any leaks. Only issue i have when bleeding is air going back through the bleeder screw. Any ideas how to stop that? Skully said that the exc m/c is 9mm which is too small, and this brake kit is sold with a 12mm m/c on motostrano. But regardless to all that, im not sure if its still spongy theres no air coming out of the tube.
 

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i have no idea how many miles it has on it at all, looked in good shape and i cant spot any leaks. Only issue i have when bleeding is air going back through the bleeder screw. Any ideas how to stop that? Skully said that the exc m/c is 9mm which is too small, and this brake kit is sold with a 12mm m/c on motostrano. But regardless to all that, im not sure if its still spongy theres no air coming out of the tube.
It could be something internal with the caliper or a piston could be sticking. When you're bleeding the brakes I would put your wrench on the bleeder screw and then attach the vacum hose to the screw. With vacum on the bleeder screw open it and keep the m/c topped off. I would let the fluid go down about 3-4 times and then close the screw with vacum still being pulled in the line. Pump the brake lever until you have pressure (or until it doesn't build any more pressure). With vacum still on the line open the screw and immediately close it again. Pump the lever again. Make sure that you have the fluid topped off during the entire process. One other thing to do is to zip tie the lever. This will sometimes allow any trapped air to make its way to the m/c. However, I used a vacum bleeder when I worked as a technician and they are extremely effective at removing air from the line.
 
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