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2006 YZ125 KYB Suspension Rebuild

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I posted a thread recently about buyer beware concerning things you cannot see when checking out a used bike. I broke into my suspension after the seals went out and found an electrical tape rigged free psiton in my non-caliper side fork. Anyway, I am now ready for the rebuild soon as I ordered all the oarts I need and have them being made and shipped to me around the end of next week. I have a few things already since I had to buy tools, but I was wondering about what some think and any tips anyone would concerning the rebuild. As I continue to type and explain what I have done, i will post what I have and have not learned from Google searches, looking through several searches of here, etc. I have a strong mechanical ability, but this is the first time for me to actually break into a set of inverted, dual chambered forks. My previous experience concerning front suspension would be with older model Harley-Davidson suspensions, i.e. true springer and not aftermarket style.

Here we go.

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As you can see, the assembly/disassembly of the caliper side looks good, including the valve comp. free piston. The oil came out well and the only "issues" are the bad seals, wipers, bushings, etc. No worries here. However, this is what I found in the non-caliper side concerning the valve comp. and free piston...

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After seeing this I knew I would be out more than the $102 I had spent in tools, oil, and a seal/wiper kit. (I got my pricing after doing extensive searches on eBay and several online parts stores.) I started calling several suspension shops around the US as to what I needed to look at and what to do, and on another forum I was given some great tips and info concerning parts, and I found out about the plastic free piston modification to help stop or eliminate free piston failure, as ell as the "works" style aluminum free pistons. I also miced out and double checked everything I could think of and found the tubes in spec, no burs, etc. Here is what I have ordered so far, including tools...

Full Rebuild Kit from Pivot Works (seals, wipers, bushings, etc.)

Aluminum Free Pistons (being machined now/this coming week)

www.privateerconnection.com

Tusk Fork Wrench

Spectro Golden 20wt

RockyMountainATV/MC

Motion Pro Seal Driver (48mm)

All Balls Seal & Wiper Kit (now a back up set)

eBay.com

Total: $321.99

I got the seal driver as opposed to using a PVC coupling or baby bottle (I found this to be a bad idea and went with the proper tool), yet I did not purchase a seal bullet as I know a plastic bag works just as well as I have seen this done many times. I also did not go to a suspension shop as they all wanted around this same price to do the work, which so far as been simple, and I prefer to have the ability, tools, and know how to continue to do my own work. (Several also made me mad by duoble charging for parts and pulled rates out of thin air here locally.) I decided to place the aluminum free pistons in as opposed to either buying the plastic ones (slightly less in price than the aluminum ones) and modding them, or buying a new valave comp. at approx. $275-$300 since the valve comp. can be rebuilt.

Any tips or suggestion will be appreciated. I am going back stock otherwise as this is truly my son's bike that I ride as well until I get my bigger bike come March. (Long story why we got this over a 2t 250cc. Ask and I will explain.) I do not jump or give it hard hits when I ride as the spring rate is not set for me, but I do take it out and do what I can otherwise. In no way is this bike abused. If I am on the right track, I appreciate a thumbs up on that as well.

Thanks for reading, and any help in advance.

Edited by BleedMarshall

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what kind of oil you will put in?

I am going to have a go with the Golden Spectro 20wt. I did an extensive amount of research into oil brands and what was reccommended and found this won out quite a bit. When I was ready to order it was between the GS 20t. and the Yamaha/KYB 5wt., and the GS was half of the price of the Yamaha, so I went with it in the end. I did not go with it for any other reason than it seemed more liked it over the other. I did not get it to add or relieve pressure or resistance.

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all ball seals have a lot of striction, oem is good and skf is best

Have you used them? Not that I am challenging your knowledge, but I read up on them and got about a 50/50 on good to bad. I went with Pivot Works for the whole shebang though, and I have heard great things about them. Remember, I am learning this end of the bike repair now, and I think I have done better than average so far in parts selection and price.

Thanks for the info so far as well.:thumbsup:

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what was the question ?

Best oil.

Best seals.

Thoughts in general of what I have done and bought so far.

Are there any other tools I will need?

Etc., etc.

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in italy for a light rider or non fast rider andreani say 2.5 w but enerall kyb 5 is the right choice,with 2.5 you have a little soft suspension ,expecially in the first part,on small bump,in little braking.20w is high viscosity oil i ve never used on dirt bike

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... When I was ready to order it was between the GS 20t. and the Yamaha/KYB 5wt., and the GS was half of the price of the Yamaha, so I went with it in the end....

would you please report how a 20wt oil feels on the track (if you are able to finish at least one lap) or do you ride in the dessert?

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in italy for a light rider or non fast rider andreani say 2.5 w but enerall kyb 5 is the right choice,with 2.5 you have a little soft suspension ,expecially in the first part,on small bump,in little braking.20w is high viscosity oil i ve never used on dirt bike

I plan on using the 5wt next seal & wiper change to see the difference in oils, if I am able to even tell a difference. I am no pro/vet rider, so I may not even be able to tell a difference. Thanks for the info here.

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would you please report how a 20wt oil feels on the track (if you are able to finish at least one lap) or do you ride in the dessert?

I will tell you how I like it. However, I ride woods and no tracks. (The nearest track is a few hours away at best, and I think four to be honest.) So the woods is what is closest for me to ride on, plus I enjoy it a bit better anyway. Less of the same thing and always some new path or track to try.

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best oil IMO is Honda 5wt the red stuff

best seals are skf

I ave read that it is good, but I also heard a lot of slag too about it. Have you use it and the 5wt or 20wt as well to give a comparison?

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i can t explain you how much density have the 20 w but with 10 w and all open click on comp you have stiff than 5w with all closed click.it s not 100% that result but similar than i have write.much difference is on low speed and little bump,you have feedback on bar

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I will tell you how I like it. However, I ride woods and no tracks. (The nearest track is a few hours away at best, and I think four to be honest.) So the woods is what is closest for me to ride on, plus I enjoy it a bit better anyway. Less of the same thing and always some new path or track to try.

I was not 100% serious :thumbsup:

I think it will be incredible stiff, except you ride it in the dessert because of the temperature and maybe long sand bumps where you need stiff compression and rebound.

nevertheless tell us your impression...

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hp5 comes out the cleanest of any oil I have seen

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