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Discussion Starter · #1 ·
Hello, your help regarding the amount of fork oil

According to the manual, there should be 458 cc on the right side, which is also 458 ML. This is what I did. On the other hand, there should be 148 mm of air height. But I manage to pump 20cm with a syringe. It doesn't make sense to me. Either I'm doing something wrong. Either the syringe is inaccurate, or the CC measuring tool is inaccurate. To try to understand what's wrong:

1. Should I also fill in the bar attached to the picture? (red circle)
2. I pump the rod but not with a special tool but pull it with an iron wire.
3. Do you measure the height of the end of the silver part (green) or the end of the golden part (blue)?

Tableware Drinkware Automotive lighting Fluid Alcoholic beverage

Font Parallel Rectangle Number Pattern
 

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The fork oil level, which is the inverse of the air gap, should be measured from the top of the fluid to the top of the gold anadized outer tube (stanchion). I recommend a fluid level about 10 mm less than stated in the shop manual. You must fully get the air out of the cartridge by pumping the damper up-and-down until bubbles stop.

A heavier spring is also recommended depending on your weight, for someone in the 190# range, a .90 or .95 spring should work well.

Just as important is the type of fork fluid you use. I also recommend a fluid that has a cSt of approximately the 16. Fork fluid weight is relative from manufacturer to manufacturer and don't usually match up. You have to go by cSt at 40 degrees Celsius. If you look online you'll find comparative fluid fluid weight tables by cSt.
 

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2019 Yamaha MT 10
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I've found many excellent videos showing this process. I always post this one because I feel like he addresses most of the questions and details we have when we're trying to figure this stuff out. You can skip through the cartridge mod to the reassembly and then it shows how to do the steps you are asking about. It's actually not all that difficult once you've done it a few times.
 

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Discussion Starter · #4 ·
Excellent explanations. thank you very much friends. I still need more help if possible. When I raise and lower the piston no air comes out. Must close it from the top? Can you also help with the directions above, I couldn't understand it from the book and the videos.
 

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Make sure the fork leg is fully compressed when you check the level. You can buy a measuring tool whick sits flat on the top of the stanchion and can be set to the desired height. Then you just suck out excess oil - job done.
 

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There's a tool I believe you know about that is inexpensive and makes bleeding the cartridge MUCH easier.

With fork fully compressed and filled, pull up and push down rod until no air bubbles append uniform resistance is felt in both directions.

Then check air gap again and add or suck out fluid to preferred level.

Do not used a machinists scale or ruler without a string (lanyard) on it. I once rebuilt someone's forks and found a machists scale that had been down there who knows how many thousands of miles!

I use the tool with the calibrated tube that fits in a matching hole in a ring with set screw that locks the tube to your fluid level. A clear hose on the tube connected to a 30 MI syringe sucks the fluid. The syringe that comes with most kits is garbage. Buy a chemical resistant few on Amazon...
 

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I use the tool with the calibrated tube that fits in a matching hole in a ring with set screw that locks the tube to your fluid level. A clear hose on the tube connected to a 30 MI syringe sucks the fluid. The syringe that comes with most kits is garbage. Buy a chemical resistant few on Amazon...
That's true, the syringes are good for about 2 uses and then the plunger pulls out of the rubber......and there's no adhesive known to man that will allow you to glue them back together.
 

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That's true, the syringes are good for about 2 uses and then the plunger pulls out of the rubber......and there's no adhesive known to man that will allow you to glue them back together.
Lube the rubber seal with silicone, no more rubber separation. And don't pull on it like a shoolboy.
 

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Discussion Starter · #11 ·
Thanks for the responses. Something is still not clear to me. I put 458 and I still have 20 smack more in the measurement of the air gap. I raise and lower the plunger, I see no bubbles.

Regarding the measurement method, I took a large syringe and attached a rigid metal tube to it directly without a flexible tube in the middle.

I can't order a special tool now because I can't leave it like that until I get the shipment. I made the stopper with a clothespin
 

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I have a copper tube connected to some clear tubing then connected to a syringe . I make the measurement on the copper tube then mark it with painters tape .Lower the tube into the forks and line up the painters tape to the top of the fork tube and draw out the extra fluid and your done .
 

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Syringes are so cheap they're almost disposable

For small volumes a turkey battery with a hose also works..
They are, $40 for 100 insulin syringes for our cat. But 3 ml takes a long time to set oil levels.

I'm guessing you don't have an EV turkey, and really mean baster. They have a multitude of uses.
 

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Discussion Starter · #18 ·
I closed the right side. Although I put 458 cc, I pumped another 20 cc when measuring the height. I moved to the other side, exactly the same story. But another problem, I raise and lower the piston, over 30 times and it still feels loose and doesn't go down as slowly as it should. what am I doing?
 

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I closed the right side. Although I put 458 cc, I pumped another 20 cc when measuring the height. I moved to the other side, exactly the same story. But another problem, I raise and lower the piston, over 30 times and it still feels loose and doesn't go down as slowly as it should. what am I doing?
This is a first gen bike? The left lag has no damping so the rod moves freely.
 
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