Everything2Stroke Forum banner

1 - 20 of 63 Posts

·
Registered
Joined
·
68 Posts
Discussion Starter #1
i might as well post what all i have done with this bike and how it all got started.

this is how i got the bike,it was someone else's parts bike and indeed in extremely rough shape.






it had the pipe,seat,side covers,cylinder,carb reed cage missing.

RH side foot lever sheared off and some other things missing or wrong for this bike,rear wheel was a oddball 17" that did not belong to this bike.
 

·
Honey Badger
Joined
·
6,471 Posts
Damn that thing was a mess! I don't know why Yamaha used those 17" rear rims, my old 81 TT250 used to have one.
 

·
Registered
Joined
·
68 Posts
Discussion Starter #3
the 175 uses a 18" front wheel,i have no clue what that rim came off of.
 

·
Registered
Joined
·
68 Posts
Discussion Starter #4
i started the tear down process.


this is the rear wheel assembly that came with the bike,i have no idea what it came off of beforehand but i knew it did not come on this bike originally.




 

·
Registered
Joined
·
68 Posts
Discussion Starter #5
egads!! look at someone sometime back used for a air filter!:thumbsdown:


engine looked like it was left in a compost heap,it was very nasty!


at least it did not have the dreaded "White Flywheel" syndrome.


the spark plug lead,someone spliced on one from a lawn mower.:Smack2:
 

·
Registered
Joined
·
68 Posts
Discussion Starter #6
the busted off foot peg mount.


i removed the engine and drained whatever was in the transmission and prepare it for the rebuild.


crankcase area had some transmission oil present,it only means one thing and that would be your classic blown primary side crankshaft seal.


 

·
Registered
Joined
·
68 Posts
Discussion Starter #7
i had to remove the adjusting nut for the clutch to get the pressure plate off,likely it got low on oil and fused the 2 clutch pushrods together.


this seal was leaking pretty bad,in fact the engine leaked at every joint.


i split the cases and removed the crankshaft.


lower rod bearing and side clearence was within spec.
 

·
Registered
Joined
·
68 Posts
Discussion Starter #8
at least it had oil in it from the transmission to keep the crankshaft from rusting as witnessed by the milkshake seen here.


seeing how it could blow this seal i began to think of ways to fortify this area.




in the meantime my seals,gaskets and bearings showed up.








i replaced the main bearings too while i was in there. all these parts came from Yambits on Ebay.
 

·
Registered
Joined
·
68 Posts
Discussion Starter #9
after inspecting the gears,shafts and shift drum i installed the new main bearings.


then i buttoned up the engine,first i removed the fused together clutch pushrod,i double nutted one end of the pushrod and used vice grips on the other side then twisted to get the pieces apart.

the clutch pushrod had a mushroom end on it where the release lever is so i could not remove it with the cases together.


the new pushrod towards the release lever end is different so it could be removed from the RH side unlike the original to this engine.this is a picture comparing the new with the old.


installing the new pushrod.


followed by a new 5/32 ball bearing.


the steel discs in the clutch have a flat side on the outer edge so they need to be installed in order,i marked the places where the flat sides go,this is the TSB notice from Yamaha on this.


i measured the clutch discs,new is 3 mm thick. mine all came in at 2.9 mm to 3 mm thick so the friction plates could be reused.


then i assembled the clutch.
 

·
Registered
Joined
·
68 Posts
Discussion Starter #10
this had to be done before the clutch was installed,remember when i was pondering the blown crankshaft seal?

i did not want that to happen on my rebuild so i ordered another seal retainer from Yamaha and installed a second retainer.


the screw head would not clear the spring on the shifting arm so i shaved a little bit of metal off of the screw.


i left enough there so i could properly tighten the screw.


i also relieved this plate so i had room for the second retainer.


then installed the retainer.


now it clears and the transmission shifts great through all 6 speeds.
 

·
Registered
Joined
·
68 Posts
Discussion Starter #11
here is the freshly buttoned up lower end.




i repainted the side cover,installed a new seal for the oil pump,installed the pump itself then istalled it on the engine.


since this engine is not going to be stock and capable of high revs i got some heavy duty wrist pin clips,these are much stiffer than stock.
 

·
Registered
Joined
·
68 Posts
Discussion Starter #12
here is some pictures of the cylinder to be used.a friend ported this and it is a stage 2 porting.




the transfer walls and the reed cage area was reinforced with epoxy due to how thin the walls turned out to be.




he signed or rather stamped his signature and what stage the porting is.sadly he retired from porting and this was one of his last ported cylinders.
 

·
Registered
Joined
·
68 Posts
Discussion Starter #13
this is the piston used,it is a piston from a YT175 choosen because it is the closest to a YZ175 piston that could be used on a 1978 DT175 engine. the edges of the piston were beveled so that stress cracks would not form.


the intake area of the skirt was madified for a longer intake duration.


here is a picture of the reed cage used,it is a Moto Tassinari reed cage for a Yamaha YZ85.it is considerably better than the stock reed cage.


i also painted the cylinder in high temprature black engine paint.


the head is a stock DT175 head that has been milled for 22 cc chamber volume.
 

·
Registered
Joined
·
68 Posts
Discussion Starter #14
here is a picture of the cylinder being torqued down in the freshly refurbished frame.i will get to the details of the frame repair and restoration soon as a lot of work went into that too.


this is a picture with the part number in view of the box the reed assembly came in.


the reed assembly here.


it has 4 carbon fiber petals.


 

·
Registered
Joined
·
68 Posts
Discussion Starter #15
the frame had it's share of broken bolts which i managed to remove.


i drilled the bolt with a small bit first taking great pains to get the holed drilled straight and center.




i worked up in size until the remains of the broken bolt was paper thin.


then tapped it to the size it originally was.


the finished result.
 

·
Registered
Joined
·
68 Posts
Discussion Starter #16
the helmet holder was in dire need of help.


i dissassembled it,cleaned the lock itself and repainted the housing.


these are before shots,i took no pictures of it cleaned up.:Banghead1:


all redone and ready to install.
 

·
Registered
Joined
·
68 Posts
Discussion Starter #17
more pictures of the lock.i managed to get the chrome cleaned up some.






other parts of the frame was stripped and repainted.


 

·
Registered
Joined
·
68 Posts
Discussion Starter #18
this pin from the shock to the swing arm is a notorious bear to remove but thankfully it was simple to remove.






after cleanup being repainted.


chain guide and chain tensioner repainted.
 

·
Registered
Joined
·
68 Posts
Discussion Starter #19 (Edited)
the reassembled swing arm.


turn signal mounts was straightend.


i removed the steering lock then started cleanup and repainting the frame.


i heated the area so the rivet can be removed for the cover plate.


i gingerly tapped the plate on opposite sides and removed the plate and rivet intact.


then using the key,i removed the lock cylinder.
 

·
Registered
Joined
·
68 Posts
Discussion Starter #20
then i removed the steering head.


then i cleaned up and repainted the frame.



then i started assembling it.

to reinstall the steering lock cover i threaded in the rivet.


then tapped it home with a small hammer.


i had a guy reproduce the steering head sticker.


 
1 - 20 of 63 Posts
Top