• RME Gear & Apparel

Gravy's Bike Rebuild

Gravy

Gravy

Ant Anstead of Dirtbikes
Supporting Member
Location
The Land Northward (Bountiful), Utah
Shims in the bike
Exhaust left: 1.70mm right: 1.70mm
So subtract .098- .148mm
I need:
2- 1.60mm - 1.55mm

[(I believe they come in .05mm increments, so I'll pick the shims in range (leaning toward the tighter one, they say)].

Intake left: 1.80mm center 1.72mm right: 1.83mm
Subtract .048- .098mm
so I need:
a 1.75- 1.70mm, a 1.67- 1.62mm and a 1.78-1.73mm

Right?
 
Last edited:
Gravy

Gravy

Ant Anstead of Dirtbikes
Supporting Member
Location
The Land Northward (Bountiful), Utah
So I picked up some shims, a coolant line O-ring, and a valve cover gasket (just in case).
So here is the plan:

Exhaust:
Left: 1.55 mm (purchased).
Right: 1.55 mm (purchased).

Intake:
Left: I can use my 1.72mm (originally from center).
Center: 1.65mm (purchased).
Right: 1.75 (thanks Russ).
 
Gravy

Gravy

Ant Anstead of Dirtbikes
Supporting Member
Location
The Land Northward (Bountiful), Utah
So I finally made time to mess with the bike and...

dun dun duuuuuunnnnn...





head gasket wasn't blown, but the bolt on the front left (where my thumb is) was fairly loose and the gasket was wet on that side, so water was definitely squeezing past it.
 
Last edited:
Gravy

Gravy

Ant Anstead of Dirtbikes
Supporting Member
Location
The Land Northward (Bountiful), Utah
The head and cylinder both look ok aside from some surface rust from water sitting in the cylinder for the last 4 weeks, but it almost wiped of with a rag.

Piston detonation.





I'll measure the bore tonight and order a new piston kit and some plastics.
 
Last edited:
Gravy

Gravy

Ant Anstead of Dirtbikes
Supporting Member
Location
The Land Northward (Bountiful), Utah
New parts! This bike will be rad when I'm done with it!

New Wiseco high performance piston



Compare the new to old piston.




and Cometic gasket kit

I also picked up a new valve cover gasket.
Almost all the parts will be new when I'm done ;)
 
Gravy

Gravy

Ant Anstead of Dirtbikes
Supporting Member
Location
The Land Northward (Bountiful), Utah
Tonkaman said:
Wow that's pretty! Are you putting it in before the ride this weekend? Is it a higher compression piston?
Click to expand...

I'll probably ride my new bike this weekend. Moab is the 13th-15th. That still gives you time to get your bike ready if you want! :D

It's a 12.5:1 compression piston, so just slightly higher compression
http://www.wiseco.com/ProductDetail.aspx?ItemID=4649M09200&ModelID=461&ModelYear=1999&AppID=2458
Wiseco has a 13.5 but doesn't recommend running it on less than 93 octane at altitude or (91 and Octane booster) and I don't really want to mess with re-jetting this bike just to sell it.

It should make slightly more power than stock and be very reliable.
 
Last edited:
Tonkaman

Tonkaman

Well-Known Member
Location
West Jordan
It wish I could get the bike together soon. After taking it to lindsay machine today things don't look good. More on that later...
 
Gravy

Gravy

Ant Anstead of Dirtbikes
Supporting Member
Location
The Land Northward (Bountiful), Utah
Tonkaman came over last night to use the press on his trans case bearings, well it was cracked!

What a stud though, he hung out at my place and helped me almost completely reassemble the YZ400F!
It's amazing that bolts you thought you had can disappear when you leave them for a few weeks.
Luckily the only bolts I lost were the radiator bolts. I bought some new ones today and I'm going to finish reassembly on it and let him ride it.

Tonkaman on the cylinder install




New piston and cylinder installed.

 
You must log in or register to reply here.
Top