What did you do to your Yamaha YZ 2 stroke today?

[218]

Not much going on so may as well rebuild the forks and polish out the tubes.

 

[numroe]

6 hours ago, 2strokeYardSale said:

The only other crank measurement I've done is a dial indicator on the piston at TDC, rotating back and forth looking for slop. I've grabbed the rotor and tried to feel for slop. The manual only shows how to measure the crank outside the bike. I should have realized my small end free play was beyond standard but less than the limit.

I use Motul 710. I don't hear any sound different from day 1, or different from the other low RPM sounds my other 2 stroke motorcycles made. And I'm sensitive enough to the sounds that I thought I heard the crank going bad but it turned out to be radio squelch.

Maybe your helmet camera exaggerates the bottom end knocking sound. Or maybe the low-vis 710 oil makes your engine sound louder. I dunno.  I do know that my engine used to sound like that and now it doesn't. Right side crank end freeplay in the bearing inner bore was the problem. 

You put so much attention into detail on your bikes and seem very particular about maintenance. I'm impressed. But I'm still unclear if you fully checked the vertical freeplay on the crank ends? I could see the movement just by holding the rod with my hand (to stop the crank rotating) and turning the clutch ring gear each way and the primary gear would lever the crank end up/down.

[2strokeYardSale]

1 hour ago, numroe said:

But I'm still unclear if you fully checked the vertical freeplay on the crank ends? I could see the movement just by holding the rod with my hand (to stop the crank rotating) and turning the clutch ring gear each way and the primary gear would lever the crank end up/down.

Like I said, I don't know how to measure that. I could guess at pulling rotor and clutch off and putting a dial on each side, but I don't know.

More things done today. Another Shinko R505 rear.

Replaced this 100 hour Shinko 546F. Got my money's worth out of it.

New chain and sprockets and sprocket hardware. 14/51 after years of 13/50. This will be my first X-ring chain.

Edited March 31, 2020 by 2strokeYardSale

[numroe]

2 hours ago, 2strokeYardSale said:

Like I said, I don't know how to measure that. I could guess at pulling rotor and clutch off and putting a dial on each side, but I don't know.

Stop thinking dial gauge. To begin with just load each crank end up/down and use your eyes to observe any deflection in the seal lips. Use the clutch ring gear for force leverage on the right side like I wrote earlier.  If you see any deflection then there's the problem, crank and/or bearing have expired.  Next is to get some large enough digital verniers and measure the freeplay between the crank end and the alum casing. Above or below the primary gear on the right side and above of below the crank end on the flywheel side.  Using common calipers with a simple thumb zero function and adjustable slider friction and it's pretty easy.  Get some help if you need someone to up/down load the crank end while you measure. 

I got an 18"  R505 on the rear of my bush YZ. Only used it once, and the grip blew me away. With Tubliss at 6 PSI.  Previous tire was an IRC VE33. 

[brownballin]

Went blue

[2strokeYardSale]

14 hours ago, brownballin said:

Went blue

I'm digging the pink grips.

I got my bike fully assembled despite some setbacks. I'm about to go fire it up now that the Yamabond has dried.

Defective master link clip. Whoever heard of such a thing?

Cool tool for chain alignment.

Cool tool for piston clip installation.

[brownballin]

20 minutes ago, 2strokeYardSale said:

I'm digging the pink grips.

I got my bike fully assembled despite some setbacks. I'm about to go fire it up now that the Yamabond has dried.

Defective master link clip. Whoever heard of such a thing?

Cool tool for chain alignment.

Cool tool for piston clip installation.

I get some grief for those, but its been kinda my thing to have something pink on all my bikes since my first bike, 1980 IT 125, never had any major injuries despite some knarly crashes, so im not superstitious but I am a little stitious

[Turboloader]

14 hours ago, brownballin said:

Went blue

Pink grips you say, secure in your manhood? LOL! Go for it bro! If remember my YZology correctly ol Brock Glover had the pink theme back in the oh so awesome 80's, nobody cared, it just looked rad back then...

[2strokeYardSale]

6 hours ago, M E T A L A C I D said:

Pink grips you say, secure in your manhood? LOL! Go for it bro! If remember my YZology correctly ol Brock Glover had the pink theme back in the oh so awesome 80's, nobody cared, it just looked rad back then...\

They even came from the factory pink for a while.

http://pulpmx.com/2014/09/16/gps-classic-steel-91-1991-yz125/

[2strokeYardSale]

I went for a short break-in ride. Half-hour then a cool-down. Repeat. Then rode the trails back home to check and re-torque things.

Everything was good except it was extra spoogey. At first I thought I could feel the difference between forged and cast piston, a little revvier and quieter.

 

 

[Turboloader]

12 minutes ago, 2strokeYardSale said:

They even came from the factory pink for a while.

http://pulpmx.com/2014/09/16/gps-classic-steel-91-1991-yz125/

I think they called magenta, lol! Of all the YZ's the 88 to 92 were my faves, cool classy lines, very slick looking graffix, and just bad to the bone all around. I had a chance to buy one, but the owner and I got into a fight, and he was pissed off and didnt sell it to me. LOL, ah youth....Love the delta box swing arm!

[Motox367]

15 minutes ago, 2strokeYardSale said:

I went for a short break-in ride. Half-hour then a cool-down. Repeat. Then rode the trails back home to check and re-torque things.

Everything was good except it was extra spoogey. At first I thought I could feel the difference between forged and cast piston, a little revvier and quieter.

 

 

What piston?

[vossman23]

On 3/24/2020 at 11:39 AM, 2strokeYardSale said:

That’s some nice scenery. Where you at?

[S.O.A.N.Z]

9 hours ago, M E T A L A C I D said:

Pink grips you say, secure in your manhood? LOL! Go for it bro! If remember my YZology correctly ol Brock Glover had the pink theme back in the oh so awesome 80's, nobody cared, it just looked rad back then...

Rad then - Gay now

[shrubitup]

53 minutes ago, S.O.A.N.Z said:

Rad then - Gay now

It's not like he had a butt plug with rainbow tassels on the end hanging out of his bum or anything. I mean, really?

[S.O.A.N.Z]

2 hours ago, shrubitup said:

It's not like he had a butt plug with rainbow tassels on the end hanging out of his bum or anything. I mean, really?

It's a wonder they didn't 

[Turboloader]

11 hours ago, S.O.A.N.Z said:

Rad then - Gay now

Who is to say what is "gay" now? If a bro rides a pink bike, gets all the pussy he wants but never lusts over another man, is he gay? You secure in your manhood bruh? LOL!?

[2strokeYardSale]

Break in ride followed by checking the cylinder nuts and head nuts.

[Scralatchtica824]

Converted to Tubliss, new Kenda tires for WV terrain and dropped the front sprocket to a 13!

 

 

Edited April 3, 2020 by Scralatchtica824

[Charles De Mar]

On 4/3/2020 at 1:21 PM, Scralatchtica824 said:

Converted to Tubliss, new Kenda tires for WV terrain and dropped the front sprocket to a 13!

 

 

If the trails are slow and tight 13/51 rocks.