Xj550 shims

Hey guys, me again

I pulled the bike back apart to do some stuff.

finally checked the shim clearance, all out of spec! Duh..


Clearances~

4: e-0.06 I-0.10

3: e-0.10 I-0.11

2:e-0.10 I-0.09

1:e-0.9 I-0.10

this explains the high compression reading I got in cylinder 4 (right?)

I’m about to go pull them and see what sizes I’ll need, I’ve just been waiting for the tool!

i also did a manual clean on the carbs(again), set the floats, bench synched, and reset the cam chain tension.

after I install the new shims to spec, I’m going to vacuum synch up the carbs then use my new colortune plug I got from chacal!

after all this I’m wondering if there’s anything else I should do while the bike has the carbs back off? Or if I’m missing any steps? Let me know!

 

I tried the "shim removal tool" and the casting of the 550 head is a bit tighter than the larger engines and I had to file and grind the tool to fit certain positions. I ended up giving up and using the zip-tie method, which works great! I'll find a link.

 

This is one thread: https://www.xjbikes.com/forums/threads/valve-adjusting-tool-xj650.129913/#post-657887

 

Im going to give that a shot!
The tool was $10 so I figured I might as well try it as well.

these would work right?

 

Alright so I just pulled them all using the wire method!


Existing shims~
4: E-265 I-270
3: E-260 I-265
2: E-260 I-270
1: E-260 I-275

What I need-
4: E-250 I-265

3: E-250 I-260

2: E-250 I-265

1: E-250 I-270

I can get all the intakes set reusing shims, and I just ordered 4 250’s!

 

I ended up just ordering some NOS shims on eBay

 

Sorry that I saw this late
@hogfiddles runs a shim pool. You pay postage and exchange your shims for shims from the pool.

 

It’s all good, I only spent like $16 including shipping, I may trade my extras to the pool for future shim needs!

 

Also excuse me if this is a dumb question, but this should make the bike run much better right? Along with the chain adjustment?

I know the synch and color tune will tell me all that but it seemed to run pretty darn good before the valve adjustment, I’m excited if it will get even better!

 

it will run much better

 

Alright so I can’t get it to start now… not even with starter fluid

I’ve tried using the color tune plug but have been unable to get it to fire at all.. backed the idle screw in, out , in, out…
Should the idle control knob be all the way in or out during tuning?

im struggling here

 

The big knob between carbs 3 and 4? It should have not been touched at all until after the bike reaches operating temperature.
Did you bench synch the carbs, or do any work on the carbs at all? I only ask because the carb butterfly valves have to be set at a proper baseline for the engine to even start, and fiddling with that idle speed knob witout the bike running changes that baseline.

 

Yeah I rebuilt them about 2 months ago, it started running sluggish again so I pulled them apart, cleaned all ports like mixture screw, float bowls, valves, etc.
Bench synched, reset floats, reset those valve shim clearances, and chain adjustment.

I got it to fire up late last night, and man it sounded really good

Smooth rpms now, before they where pretty jumpy and choppy

Throttle response is practically instant now, and I can adjust the idle rpms perfectly with the knob.(before it didn’t matter how far in or out the knob was, the bike would idle around 1400 unless the butterfly’s were completely shut)

although after a short ride it died, started back up and was choppy, then after I revved it a few times it ran normal again so I assume I’m running rich.

which makes sense because I haven’t colortuned yet!

but man do these bikes really rip when they’re running the way they’re supposed to.. I had put off the valve shims for some reason and I’m really glad I listened to you guys and got it done.

 

I got back to it today and had some trouble again, couldn’t get it to fire on all cylinders

what is a good baseline to start a tune on these carbs?

I know the mixture screws about 2 1/2, what about that idle knob? & I used a 1/16 drill bit for a bench synch

 

get it started and warmed up then set idle to 1100rpm all the butterflies will move together as you adjust the idle.

go to 2-3/4 open on the mixture screws

 

okay, should those butterfly valves be completely closed from a cold start? Or barely cracked? Or 1/4 open?

I’ve been trying to do it from barely cracked - closed

 

if you look in the top of carb throat you will see some tiny holes fed by the pilot jet circuit you should be at half moon to just past the hole,

 

Nice! Thank you a ton