screw in the head pipes

can anyone tell me what the hex head screw is for in the head pipes of an xj550?

it appears as if their sole purpose in life is to prevent the locking collars from coming off the pipes...

any suggestions?

thanks

d

 

I saw someone call them drain plugs.
I wonder about removing them when winterizing to prevent water pooling, and reinstall when prepping for the road in the spring. I dont have a shop or owners manual yet myself.
here we go
http://xjbikes.com/Forums/viewtopic/t=2 ... +plug.html

My bad: I did miss read that winterizing thread - it states to pull the plugs and fog the cylinders - meaning spark plugs.

 

Actually, they are for the YAMAHA Exhaust Gas Analyzer Probes.

That WAS the was Dealerships set-up the individual Carb Mixtures. The Yamaha EGA Machine wasn't much of a success. The EGA Machine was prone to break-downs. Expensive to fix. Yamaha quit fixing them and the Dealers quit using them.

Now, those screws are Formula-1 Screws.
Nothing gets hooked-up ... you just Pull-'em out for FUN.

Makes the Bike sound like a Formula-1 Car and Match-rev down-shifting will produce that "Pop, pop-pop-poppidy-pop-pop-pop" you love to hear when you are out playing "Top-Gun."

 

sweet, and taking the plugs out and leaving them in the toolbox at home also lowers the total weight of the bike for those crotch rocker stoplight racing sessions. Whats that about - 2 grams at the most?

 

Yeah, the Exhaust Gas Analyzer machines were problem prone, but I did a lot of good with the one at our shop. When hooked to each head pipe, and isolated by a valved manifold, you could dial in each carb fuel screw to 3-5% Carbon Monoxide and really smooth out vibrations and throttle response. The frugal guys would get 3%, the racer guys 5%. We used to add this service to the normal tune ups for an added cost-well worth it in my opinion (plus I worked commision... :lol: ). I always put my bikes on it, even riv-nutting the fittings into 4-1 headers for sample ports. Some service shops now have the Snap-On 4-gas analyzers that work much better than the Yamaha 2-gas models...

 

And then along came Digital Fuel Injection.
No more little brass screws to tweak.
Just a hand-held plug-in reader to hold.
These kids today are soooo spoiled!

 

well on my OLD (and to be replaced) headpipes i managed to break EVERY ONE OF THEM off in the hole...

yes i used LOTS AND LOTS of liquid wrench. i thought i was going to need the exhaust collars. but i didnt...

d

 

I think LT must be getting ready to light-up that 550 of his. I hope it runs like a switch watch.

Anybody close enough to do a Colortune on that Bike of his. Everything else ought to be pretty darn close to already dialed-in.

I hope!!!

 

Rick...

im still a ways off...

i worked today, im working tomorrow and im not sure what kind of OT im working all next week...

i dont expect to be 'on the road' this year (plates and insurance issues) but i WILL be testing!


d

 

No harm in mounting the Carbs and spending an hour just smoothing things out.

I have a good feeling that the Precision Bench Sync is going to have you in the Ball Park.
But, I know you are probably the kind guy who BallPark aint good enough ... you want to be standing with both feet on Home Plate.
We can do that!
No problem with those Mikuni's and the Pilot Screw Threads chased with the Tap and Oiled-up nice for the Tweaking.

 

well i think the 'sock bandit' has broadened his horizons...

i seem to be missing the 10mm socket and ratchet out of my metric set. luckily ive got another 3/8 drive ratchet and i can use the deepwell 10mm socket...

i seem to have a few extra bolts laying around. now granted i dont have EVERYTHING put back on but i have 4- 10mm bolts that i THOUGHT were for the front fender. i cleaned them up and phospated them. went to put the front fender on and...there were 4-10mm bolts in the mounting holes! then i didnt grab enough cap screws today for the carb caps. luckily im working tomorrow :mrgreen:

got the mufflers hung (loosely) along with the new(er) headpipes. have to get in the mood to lay on the floor to do the collector

its bed time for the daughter unit so i guess im done for tonight...

d