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Discussion Starter · #1 ·

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Discussion Starter · #3 ·
Got mine from Wayne a couple weeks ago, everything's good so far but I run my chain looser than most do.
My chain was stretched when I got the bike stock with 7k miles on it. Installed a new chain and a Yuminashi manual CCT that uses the stock spring, so it's definitely not too tight either. Motor is over 11-12k a lot, and this will definitely give me peace of mind......
 

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Discussion Starter · #5 ·

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Discussion Starter · #7 ·
Let's hope the bearings are up to the task. Time will tell.

What do you use as a guide for setting cam chain tension?

The sound method does not work for me.

I just make sure there is some slack in the chain in cam chain tunnel near the guide wheel, but not enough slack to contact the wall with max finger pressure.

P.S.: Joined the KTM 390 forum btw. Considering the 390 or 890 as next bike.

390 wet weight about 390lbs (ironic!) 42 hp
890 wet weight 405 LBS 111hp

I wish the 390 weighed less!

My Grom wet weighs 209 Lbs with around 20Hp
390, where did you see that? After the exhaust swap I am fairly sure mine is sub #300....... I am pushing 45ish hp to the wheel on my 2016 too :cool:

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I have a Yuminashi manual CCT on mine, it uses the stock spring and push rod (has a hard Yuminashi button on it too). I tighten it until I hear/feel the slop go away completely, then back it out about a quarter turn and lock it down. Really don't think it can get too tight with the stock spring in there & the Yumi adjuster is only adding a bit more pressure to it, but if you have the other type that eliminates the spring and stock push rod, I can see that easily being over tightened.
 

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Discussion Starter · #9 ·
Just looked up a 2020, guess they added more weight to them since the 2016 that I have! I imagine you can still get them under #300 though, most is in the exhaust/cat.. And you cannot really feel the weight, they're so well balanced that they flick around just as easy as a Grom.
 

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Discussion Starter · #10 · (Edited)
Just looked up a 2020, guess they added more weight to them since the 2016 that I have! I imagine you can still get them under #300 though, most is in the exhaust/cat.. And you cannot really feel the weight, they're so well balanced that they flick around just as easy as a Grom.
The damn rear shock probably weighs 15lb or so too! I put a 07 R1 shock on mine, its a bit longer and fully adjustable and shaved more weight, made a world of difference.
 

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Discussion Starter · #12 ·
Good pics and explanation of the differences between Yuminashi and Gromfatherz type chain tensioning rod, in this thread:

Cisco, always with the informative threads! LOL..... Wonder how his Benelli TNT 135 is coming along.
 

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Discussion Starter · #15 · (Edited)

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Discussion Starter · #23 ·
Going to make sure the bolt holding the wheel has some thread lock on it before install.

Things that worry me.... A bearing failure, while unlikely, can be catastrophic.

The bushing approach eliminates that issue at the cost of a drop more friction.
Definitely a drop of Loctite on the threads for piece of mind.
 

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Discussion Starter · #27 · (Edited)
Appreciate the info, been waiting to install mine til I get the 4th bearing support modified (was given one for OG, have to get turned down on a lathe to fit SF) so I can do it all at he same time "while I am in there".... Love that the snap ring gives the ability to change out the bearing as needed.

Looking at the sprockets, I think I may go over them with a wire wheel to smooth out the rough edges before installing also.
 

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Discussion Starter · #31 ·
Installed the speed shop unit.

The Takegawa unit that came out actually seems perfect. No significant wear. I like the beefiness of the Takegawa arm and the weep hole for lubrication of the bushing at the pivot.

The speed shop unit has the advantage of ball bearing metal wheels, if in fact that will increase reliability. Time will tell.

I set tension of the cam chain using the manual tensioner till finger tight and then backed of 1/4 turn. Chain is snug. Finger tight is actually misleading. I gently turn in the adjuster until I feel slack taken out, not until max finger strength, certainly not max wrist strength. Then, I back out 1/4 turn. I confirm that the chain has slack but is snug enough not to jump the sprocket.

"WHAT PART OF "FINGER TIGHT" DO SOME PEOPLE NOT UNDERSTAND?

The object is to take only the slack out of the cam chains, not put any tension on them. It is worse yet if you start to bog the engine at idle. That is damaging tight. The goal here isn't just to have everything silent, it is to know when you have proper cam drive adjustment. It can be silent, but be way too tight.

Fact is it would be better to have a tiny bit of play than too tight. Finger tightening is plenty adequate in every case I've encountered including tens of thousands of miles on my own bikes. I don't care who's manual tensioner you are running, finger tight is finger tight and is adequate to do what is necessary. Any thing more just promotes premature wear or possible head damage. You wouldn't overtighten your drive chain, why would you do it on your cam drive chain?

I have had a few people who bought tensioner kits from me have noise issues when they overtighten the adjusters. Once I get them to readjust them to finger tight the noise may go away or they found it was coming from another source. With around 400 tensioners around the world, I have yet to have anyone have any problems when adjusting them finger tight. The only issues are when they don't follow instructions.

Take this in the spirit it is meant - to open some riders' eyes to the correct adjustment to keep their bikes running. Nothing more and nothing less."



Started up and runs fine. Full test to follow.

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Good stuff! How much weight was shaved off that flywheel? Notice a quicker rev from it? I noticed immediately the difference in how quick mine revved from the Takegawa light weight spinner.
 
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