Throttle Shaft Seals

So, I did a Valve Adjust/Carb Sync today...
The valves were so far off it isn't even funny...

First Check:
Cyl 1:
Intake: .05mm - 275 shim
Exhaust: .05mm - 260

Cyl 2:
Intake: .10mm - 280
Exhaust: .17

Cyl 3:
Intake: .10mm - 285
Exhaust: .10mm - 265

Cyl 4:
Intake: .8mm - 280
Exhaust: .11mm - 270

Set to:
Cyl 1:
Intake: .15mm - 265 shim
Exhaust: .21mm - 270

Cyl 2:
Intake: .14mm - 275
Exhaust: .17

Cyl 3:
Intake: .12mm - 275
Exhaust: .18mm - 255

Cyl 4:
Intake: .14mm - 270
Exhaust: .19mm - 260

Gotta keep an eye on Cyl 3 intake.
Do any of you think the .12mm on Cyl 1 Exhaust is a problem?

She sounds a lot better and we'll see how she runs tomorrow.

The only odd thing I that there was what seemed like oil in the YICS passage. Is that normal?

Cheers
Dave

 

"The only odd thing I that there was what seemed like oil in the YICS passage. Is that normal?"
I've noted this on a few of mine and chalked it up to leaking valve seals and coking. I'd like to hear a few other ideas fellas...

 

Our Yamaha tech actually thought that whilst there may be some oil in the passage, it is more likely just gas that settles inside and then has been boiled and re-boiled giving it the dark, oily viscocity. But that was just his specuation as it has been many years since working on these bikes.

Cheers
Dave

 

So, she is running much better after doing the Valves and Sync but still slightly hangs. Such I have ordered all the parts for carb rebuild from Chacal. Tore my spare carbs apart today and have some questions about if certain parts can be re-used...

Float Needles: The bike wasn't flooding before so I would assume they work, but there is a slight bump on them. Can I use these or do I need to get all new float assemblies?


Enrichment: Do I need to replace the boots on the top of the plungers?


Mains: I took the jets out a long time ago. These are the washers that go under the main jets yes?


Going to take the carb bodies to work to run through the agitator once my parts come in with the JIS screwdriver. Also re-jetting the mains while I'm at it as I have an essentially open exhaust.

Also got a colortune so I can set the idle mix right when they're done.
Does using a colortune on a cylinder that's burning oil damage anything?

Any notes or input from anyone about this rebuild?
Other tips I am probadly forgetting?

Cheers
Dave

 

The float needles are probably history. New ones are indicated.
The jet washers are reusable, just clean them up.
The enrichment plunger boots are unobtainium, treat them well and preserve.

 

I agree with robert. The needles are shot see the shiny part where it rubbed off the viton (i think thats what its called) that should be smooth with no bumps. They might not be leaking right now but they will. Hopefully you have them marked the wear marks are from it seating. If you don't put it back in its corresponding seat it will never seat again properly

 

May have a lead on some plunger boots, will try to replace them as they didn't come off very easy...

I have kept everything short of the choke plungers seperated into which body they came from. Will look into replacing them but might end up using whichever set is better from my old and current carbs.

Cheers
Dave

edit: Scratch that, found some keyster Valve Assemblies in a drawer at work for near free. Will be replacing them.

 

Indeed I have found some new Choke Plunger Boots adn 5 are on their way to me.

Cheers
Dave

 

If those plunger boots work, get a part number for us! I'd like a set!

 

I got them from Yamaha themselves. Sounds like I may have almost gotten the last set in North America...

Cheers
Dave

 

well looky looky what came in the mail today

Got all the parts needed for a full carb rebuild and tune

Shaft seals, clips, and shims
Fuel line o-rings
Float valves
Jets
Butterfly Screws
#2 JIS for disassembly

and just for the hell of it:
Choke plunger boots
Exhaust gaskets

So, time to:
disassemble
Polish slide bores
run bodies through the agitator
rebuild
Colortune
Sync
Jet
Re colortune and sync
and then see if my damn idle will work nicely

Many thanks to Chacal!

Cheers
Dave

 

I'm drooling...

 

Well, here we go




Step One: Break down... Done
Step Two: Clean...
Step Three: Rebuild
Step Four: Ride?

Cheers
Dave