Fork oil

Missyl1713

Missyl1713

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I'm waiting on my shop manual to arrive, but it probably won't be here till next week, how hard is it to change fork oil? 10w is good? How much? I'm doing my steering bearings this weekend, so I'll have the forks off anyway. Any tips, as always, are greatly appreciated!!!!
 
Missyl1713 said:
I'm waiting on my shop manual to arrive, but it probably won't be here till next week, how hard is it to change fork oil? 10w is good? How much? I'm doing my steering bearings this weekend, so I'll have the forks off anyway. Any tips, as always, are greatly appreciated!!!!
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I wouldn't go with 10W oil. If your looking to change the way the front feels by going up in weight, I suggest a 7.5WT oil instead. I went with a 10WT when we did my forks and the ride was a bit too hard afterwards. I have made adjustments by going lighter on all my settings but the next time I'll just go with the 7.5WT instead.
 
FZ1riderNY said:
I wouldn't go with 10W oil. If your looking to change the way the front feels by going up in weight, I suggest a 7.5WT oil instead. I went with a 10WT when we did my forks and the ride was a bit too hard afterwards. I have made adjustments by going lighter on all my settings but the next time I'll just go with the 7.5WT instead.
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I just went to 7wt on my wife's bike and it feels really good now!
 
From all the videos I've seen so far, basically you remove the fork, pull the silver cylinder out of the gild cylinder, remove an encap an dump the oil out, advisable to leave upside down over night to drain sludge, then use a measuring cup to refill the cylinder, replace cap and reassemble. Sound right?
 
Actually, you want to pump the fork several times slowly to release to oil from the valve assembly while it is upside down. No need to leave it over night. Now, to fill it, Billy? What was the measurement for the oil from the top of the fork with the spring removed?
 
I think Billy put the instructions in a thread here already. I just do not remember which one. There is some in the Busted Knuckle thread and I think he had a thread afterward with more stuff including the shop manual pages and a correction.
 
That would be 140mm or 5.51 inches of fork oil. What we did was take a plastic tube and marked off 140mm on it. We inserted it into the top of the fork tube and checked it until the oil just touched the bottom of the tube.
 
FZ1inNH said:
Actually, you want to pump the fork several times slowly to release to oil from the valve assembly while it is upside down. No need to leave it over night. Now, to fill it, Billy? What was the measurement for the oil from the top of the fork with the spring removed?
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FZ1riderNY said:
That would be 140mm or 5.51 inches of fork oil. What we did was take a plastic tube and marked off 140mm on it. We inserted it into the top of the fork tube and checked it until the oil just touched the bottom of the tube.
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I doubt the Gen I and Gen II measurements from the top of the fork tube are the same.

I know I have said it before and I will repeat it again. There is no way that you will get all of the old oil out so you just can't say oh the manual call for xx ml (or oz) of fork oil and you put that in. You need to put in most of the oil in and stroke the dampening rod to get all the air out. Then you put in the rest of the oil so that it's at the level that the manual calls for (from the top of the tube).
 
NJFZ1 said:
I doubt the Gen I and Gen II measurements from the top of the fork tube are the same.

I know I have said it before and I will repeat it again. There is no way that you will get all of the old oil out so you just can't say oh the manual call for xx ml (or oz) of fork oil and you put that in. You need to put in most of the oil in and stroke the dampening rod to get all the air out. Then you put in the rest of the oil so that it's at the level that the manual calls for (from the top of the tube).
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Now that you said that I just realized what I had written. Maybe I should clear that up. It's 140mm or 5.51 inches from the top of the fork tube. So how much fork oil is not relevant, just make sure that it comes to within 140mm's from the top of your fork tube.
 
I just had my FJR forks and Wilbers shock serviced by GP suspension in Oregon City,OR. Amazing to watch them work, Ben stripped my forks completely for a good cleaning etc.
I did talk FZ1 too,they suggested using Kerosene to clean the inside after stroking and draining the old fork oil to really clean the old crud out- wait till you see how crudy it is. Also Dave suggested clean and replace fluid every 15K mikes.
I replaced the stock FJR fork valves with their own in house valves and other parts too. Really like it.
They do make fork valves for the FZ if interested and/or you can ship them in for service.
Find them on the web gpsuspension.com
Good luck, happy fork oil change!
 
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Well I didn't get time to change the fork oil while doing the steering bearings, it was hot, I was short on time a bit. Realized this morning that I accidentally routed my right brake lime around the outside of the fork rather then the inside when I put the forks back on. DOH! Guess I will be doing fork oil soon. :)
 
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