1978/1979 "yz 175" questions

[schmanman]

1978/1979 "yz 175" questions! a one of a kind bike!

Hi, I joined this forum about this time last year. I recently aqquired a new bike, it's quite interesting.

it is a 1979 yz 100 monoshock frame with a 1978 it 175 engine. this is a former ice racing bike, and because of it's power to weight ratio, it flies!

I got it for $200

the bike has a brand new top end, bored .050 over, with new piston and rings, because they ran the mix too lean and burned a hole in the top of the piston. it has N.O.S reeds, too.
never to be ridden or even started again...... under his ownership.

it got put in the corner of the garage, everything in a rubbermaid tub, waiting to be reasembled. the guy got a kawasaki ninja project bike, and needed to make room.


I made $193 on copper, so I started looking for a fixer upper on craigslist. sure enough, this great deal was on there.
the bike was only missing tranny oil, some fasteners, a chain, and an exaust pipe.

here's some pics....

http://i343.photobucket.com/albums/o442/schman-man/HPIM1853.jpg

http://i343.photobucket.com/albums/o442/schman-man/HPIM1852.jpg

http://i343.photobucket.com/albums/o442/schman-man/HPIM1851.jpg


I'm 16, this is my second project bike, the first being a free 1976 ke 175.

so, now, my question....

the clutch, no matter how much I adjust the threaded things on the cable, does not work.

the pull feels great, and all the parts are there.

as I can figure out, there a few things that could be going on.

-the clutch pack could be too tight, too much torque on the bolts and springs. so, no matter how much I pull, the clutch plates will not seperate.

the more likeley scenario....

scenario "B"- the clutch, which worked great before the top end rebuild, sat fo a LONG time without any oil. the engine still has not been run, since I put in the oil two days ago. (waiting on the exaust pipe) the clutch pack just needs to be warmed up and lubricated and stuff after sitting so long.



the clutch may just need to be "freed up" too.

I once read a thing about a guy who let his bike sit for years, got water in the clutch, and needed to break his clutch loose for the pulling of the clutch lever to do anything.

while not that drastic, this may be a similar case.


I am gonna go with scenario "B" If after riding it for the first time, this Is not the case, I will open it up and take a look.




also, andyone have any good info on this bike or engine? any good things about the engine or chassis?


anyone have any imput? do you agree with scenario "b"? scenario A? scenario C?


Thanks!

-Alex

 

[CRazy250]

haha i totally wanted to buy that off craigslist, when i saw that i was like too bad i dont have 200$...... take the clutch apart and make sure its clean and reassemble it and lube the cable up real good or just replace it if its too bad.... sweet bike have fun riding!

 

[whenfoxforks-ruled]

If you took the clutch apart, made sure all the parts got put back in properly. The clutch should work normally. Unless there are different springs, or that old dog just has a hard pull. http://www.bikebandit.com/houseofmotorcycles/showschematic/m7296sch223720, but it sure sounds like something is missing, option c, is that little ball in there? Its size is so important, a bb will not work!

 

[schmanman]

the ball bearing...

what exactly does it do?


would the clutch pull feel normal, and pull all the way without it?

 

[whenfoxforks-ruled]

the ball bearing...

what exactly does it do?


would the clutch pull feel normal, and pull all the way without it?

If The clutch pull feels normal, what is the issue? Why do you "think" the clutch is not dis-ingaging? I am fishing that parts are missing!

 

[schmanman]

because, the clutch pull feels normal, but when I go to roll the bike with the clutch pulled in, the motor still turns.

 

[whenfoxforks-ruled]

This is normal. Some, while the motor is running, go to put it in gear, and it will lurch and die. Normal for some set ups/models. As long as there are no grooves in the basket, or the inner pressure hub. Different oil can make a difference in its intensity. But, on a dead engine, all bikes will drag to some extent.

 

[schmanman]

ok, thanks.

my ke 175 does'nt really.

this is also a former racing bike, so the clutch is probobly pretty tight, am I right?

so you think that once it's running and all lubricated, it'll work fine?

 

[whenfoxforks-ruled]

Your going to be the judge of that? Any unusual sounds, shut it off. From what I can decipher, it should be okay.

 

[schmanman]

yep. I guess I'll just have to wait and see! :)

anyone else have imput or ideas?

 

[schmanman]

also, does anyone know how to adjust the rear shock on the yz 100?

 

[zoommx]

The only adjustment available is spring preload. Remove the seat to access that adjustment. I don't recall for sure, but there may be a small phillips head screw that locks the preload adjuster, may even have a circular piece of wire under the head of that screw also.

 

[schmanman]

ok, great, thanks.

 

[Skookill]

My 70 AT1 125 sat in a barn for about 20 years. I cleaned the old gas out of the tank, cleaned the carb and it fired right up. The clutch was frozen though. I'd pull the clutch lever cable and it felt fine but it wasn't disengaging so when I popped it into first it would lurch forward and stall. I left it in first and just pushed and pulled on the bike about 20 times and it broke free. Works fine still. Nice looking YZ by the way!

 

[schmanman]

thanks! yep, I'm thinking that that will very well might be the case. dunno yet, as my pipe should get here in the next three days.

also, thanks for the complements on the bike....

I'm really happy with it.