more fun with carburators

Alright, I took 'em out, cleaned 'em out according to rick's faq. My carbs, on my 1982 xj650j, did not have:

1) the beanie gauze tips on the float valves.
2) the spring, washer and o-ring under the pilot air jets. There's nothing under the jets in the valves they screw into.

I didn't lose them. They just weren't there on any of the carbs. Did some of the hitachi models lack these components?

And

1) The pilot and main air jets under the hats and brass cover were tightened all the way down to the metal, on all the carbs. and they don't have the needly looking extensions shown in the haynes illustrations, on the jets or air jets. Is any of this normal?

Someone also has stripped one of the main jets pretty badly. Dremel time...

 

Not supercritical, but nice to have, methinks. My spare set of carbs didn't have them.

You're probably thinking of the idle mixture screw, not the air jets. Those screws are located outside on the carb body next to the starter plunger.

Not sure which "needly looking extensions" you're referring to in the manual, but... wait, I see what you're talking about. Yes, that's normal -- mine don't have those either. If you get the XJCD and go over the carb cleaning tutorial from Duane Verhey, you'll note his air jets don't have them.

 

Since you don't know the terminology, give us the page # in the Haynes manual so we can look up what you are refering too.
The pilot mixture screws have the spring under the screw followed by the washer and then the oring. The washer hides the oring and looks like you are looking at the bottom of the seat. I use a drywall screw very carefully inserted so as not to damage the seat and turn it a turn and a half to remove the washer and oring.

 

I'm attempting to use the terminology as supplied in haynes. My confusion, I think, is where the pilot mixture screws are. I haven't found them. I understood them to be shown in haynes figure 7.9b on page 123, referred to as main and pilot "air jets.".

 

Flip over to page 128 and look at pic 12.3. That is the mixture screw. The screw comes out first followed by the spring. The washer is next with the oring under it. The washer and oring are removed as described in my last post.

The air jets on pg.123 usually don't need to be removed for cleaning. Also the Haynes manual has them reversed. Pic 7.9c shows the main and pilot "fuel" jets. These are removed and cleaned overnight in "Carburetor and small parts cleaner". This stuff:
http://www.gunk.com/prod_photo.asp
Care must be taken to keep the parts in their same respective carburetor bodies. I use glass salt shakers and number the aluminum tops by scoring with a Dremel tool.
DO NOT immerse or clean the carb bodies in this stuff. There are rubber parts inside the carbs that it will dissolve to dust. ONLY brass parts go in the "Carburetor and small parts cleaner". The carb bowls or other metal parts can be cleaned in it but make sure the bowl gaskets are removed. Anything rubber or plastic will be destroyed. I am sure Rick's guide states all this but I can't be too careful with "your" carbs! Don't just read Rick's guide but study it like he will come to your house and give you a semester exam on it!

 

The AIR Jet on Hitachi are Internal. Hidden beneath the Rubber Diaphragm and to the right of the Diaphragm Piston Bore.

Early Bikes have these Jets covered by an Air Flow Regulating Cover Plate. Later Models did away with the Plate but still have the threaded hole for the Cover Plates special fastener.

You do not have to remove the two Air Jets to get the Pilot AIR and Main AIR Passages cleaned-out with Carb Cleaner.
You do have to have the Pilot Jet pulled to let the flushing spray exit the Pilot FUEL Jet opening.

You do need to have the Center Emulsion Tube pulled to flush the Main AIR Passage with Carb Cleaner sprayed directly onto the AIR Jet.

 

They have the *labels* reversed, not the jets themselves.

 

Yes it is just the labels and the jets are in their correct placement. Thanks for the clarification. I should have explained that a little further and thanks so much for the correction Schmuckaholic!

 

i removed my pilot mixture screws and didn;t have any spring , washer or o ring either...

 

They're all still probably in the hole.

 

Snag a set of Parts Carbs off eBay.
You'll benefit if the small stuff and the Diaphragms are in good shape.

The Pilot Screw fits through a spring.
The Spring rests on a tiny flat washer.
The Flat washer protects an even smaller O-ring.

Screw - Spring - Washer - O-ring

 

That's weird -- the Mikuni doesn't have the springs or washers by design.. But the 650 uses Hitachi, right?

 

Oh yes they do!

 

Are you sure you removed the pilot screws and not the choke plungers which don't have the springs and such? The choke plungers use a 10mm socket or wrench for removal and the mixture screws use a small flat head screwdriver.

 

There's a chance that he doesn't see the Pilot Screws because they might still have the Plugs covering them.

That would be "Good News; Bad News"

Good, because it would all be new and intact.
Bad because of the possibility of damaging a Screw top getting the Plugs out.

I don't drill them out any more.
I grind the bulk of them away with a Dremel until they are just about gone and then I pick them out with a Dental Instrument.

 

Gone from the bike for a few days, racing shopping carts over the manhatten bridge in the Idiotarod. Good fun.

Found the pilot screws. They were in fairly good shape, got them out with very little trouble. One of them was indeed screwed all the way down - is there a factory standard number of turns to set it at? The others were all between 3 and 4 four turns.

And one of my main jets (pic 7.9d, page 123) is stripped beyond recognition. Recommendations on removal?

Other than that, the carbs seem to be in good shape, ready for tuning.

 

The Factory setting for Mixture is Two and one-half turns OUT from the Bottom.
In MOST Cases ... 2 1/2 is a little bit lean causing the associated problems of lean-ness and Idle that is rough or "Hunts" a little bit.

Those of us who have access to a ColorTune Device have found that the Piolt Screws make a better Mixture set closer to 3 Full turns Out.

Three turns is Ballpark.
The precise Mixture setting will depend on the condition of your Engine.
Once you have the Best Idle achieved on a Hole with the Pilot Mixture Screw ... at some arbitrary point best for your Engine ... at 3+ Turns OUT ... the optimum Air~Fuel Mixture will be within a FEW DEGREES of turning the scews In or Out ... NOT fractional values.

To get Dialled-in you need to find where the Mixture is burning at a good A/F Ratio and TWEAK the Screws to give you a GOOD "Plug Read"