Getting my 550R to road worthy status

this is my 4th ujm but first yamaha. this one is really clean with just over 6000 miles.. all mechanically original to the best of my knowledge.. came with backrest/rack. previous owner had replaced the tires, sprockets, and cables. I have since replaced the air filter, battery, spark plugs, oil and filter, brake fluid, the rocker cover gasket, and handlebars to superbike with renthal grips. It has always started and ran seemingly very well\. so I havent gotten into the motor or carbs as I thought that all was good to go with maybe a final tuning after I had replaced all the standard use /wear parts. now that everything basic is out of the way.. 1 and 3 are not firing!!!!!! I've been letting it run with plenty of lucas to see if the carbs will clean themselves.. my worst fear is that when i changed the rocker gasket.. i used some gasket dressing to hold it in place for assembly.. that some excess may be gunking up the valves. I've never done a valve job but I guess I'm going to have to open it up and see whats going on in there.. I've checked the plug gaps and rubber involved with fuel and induction. plugs are all sparking and rubber seems to be in tact. I know there are plenty of you in here who can help me along the way.. I'm in it for the long haul with this bike and this is just a little start up info on where I'm at.. gonna go run it at and poke at it a bit today, will give updates and see if anyone will chime in with troubleshooting ideas and help figure what the REAL problem is.. thanks.. merry christmas

 

welcome to the forums and congratulations on the purchase.

CN

 

Merry Christmas, and sorry to hear about your 550. But not to worry...there is a member (BigFitz) and it's almost like magic..whenever somebody mentions problems with a 550, I think a special light flashes in his house or something, anyway, follow whatever he suggests... He'll for sure address your most serious problem (not firing on 1 & 3), and give you plenty of diagnostic information so you won't chase your tail for months...FOLLOW HIS ADVISE...TO THE LETTER.
You'd also be wise to remember these bikes are well over 30 years old and unlike a 30 year old car, if something fails, more than likely, you're headed for the pavement...even if stuff looks like new..check the date codes..Tires, Brake pads, lines and seals, all Bearings, all Seals...Get a factory manual and perform ALL routine maintenance...CHECK/ADJUST YOUR VALVE TOLERANCES, it seem pretty complex at first, but Fitz has a terrific writeup, follow it like the law and you'll have no problem. Finally, at some point get around to cleaning/adjusting your carbs...again, might seem a little daunting at first, but there are plenty of very knowledgeable members here who are very generous with their time and experience...just listen to them and remember...There are no shortcuts...do it right and that 550 will scream!

 

Welcome. I didn't see anything in your post about checking valve clearances. First check is due at 3000 miles and every 5000 miles after that. As far as the carbs, the rubber components are 30 years old. If they're compromised, ain't no amount of Lucas going to remedy that. Do a search on setting valve clearances. BigFitz has an excellent write-up. For the carbs, search for "The Whole Nine Yards" and "The Church of Clean". Also, pull the rear wheel and check the brakes. The lining can separate causing the rear tire to lock up. Don't be afraid to ask questions. Be patient. Be thorough. And believe me, you'll have a bike to be pride of.

 

It's kind of like the "Bat Signal."

CHECK THE VALVE CLEARANCES ASAP!!! (Howzat?)

The first check was due at 3000 and they are supposed to be checked every 5K thereafter as above. I got my '83 with 7100 miles on it and 7 of 8 were tight.

The valve cover gasket itself is a start; but there is more to it than that. The rubber/metal composite "donuts" on the hold-down bolts are what actually push the cover against the gasket; the bolts have stop collars to prevent overtightening. Once the rubber donuts get mashed flat and baked hard, even a new gasket will leak. Gotta replace the donuts with the gasket; the good news is that they can then be re-used for subsequent valve clearance checks.

Valve adjustment how-to (done on a 550 Seca, go figure) http://xjbikes.com/Forums/viewtopic/t=14827.html

Part Deux: http://xjbikes.com/Forums/viewtopic/t=29209.html

The rear brake thing is serious biz; both of my 550Rs were delaminated: http://xjbikes.com/Forums/viewtopic/t=15874.html

Front brake lines: http://xjbikes.com/Forums/viewtopic/t=41400.html

What a Mikuni BS28 looks like inside: http://xjbikes.com/Forums/viewtopic/t=31061.html

This is 550 Seca specific, important, and isn't in the manuals: http://xjbikes.com/Forums/viewtopic/t=31872.html

This is also not covered: http://xjbikes.com/Forums/viewtopic/t=19538.html

And you might like this one: http://xjbikes.com/Forums/viewtopic/t=22823.html

There are a few more 550 Seca or 550/600-specific "how to" articles in "XJ FAQ Suggestions."

Welcome aboard. XJ4Ever has all the parts you'll ever need; and you'll need a service manual. The aftermarket book for the 550s is by Clymer; or you can track down a factory book. If you plan to keep the bike for a while, I'd recommend both.

Last but not least, #1 and #3 DO NOT share a coil, so the issue is likely carb related. (One coil fires 1/4 the other one fires 2/3.) Or you need new spark plugs. (NGK D8EA.) But check the valves first.

 

Fitz has got his "550 Sense" on at all times. Lucky for us, too! Welcome to the boards!

 

does anyone have the line on some shims? looks like $9.00each w/ free shipping is about the best i can find.. also.. at .127 on three of my intakes would it be recommended to bring them up to .137 if .146 is the best i can do on my 4th?

 

and thanks for the welcome everyone.

 

and yes they were all tight... #4 intake was at .076!!! oddly enough.. #3 which wasn't firing, was the only cylinder with both valves in spec.. so we're thinking carbs are we? lol.

 

How, pray tell are you going to adjust a clearance from .127mm to .137mm when shims come in .05mm sizes?

If you have an intake valve measuring .127MM, it is in spec.

A thicker shim would take it to .077; a thinner shim to .177, both out of spec.

DROP the .007mm; if you're seeing .127mm then you're in spec (.12mm is within the range of .11m ~ .15mm for an intake valve.)

Remember, there is one size shim and one size only that will put any particular valve in spec.

 

Welcome AnchorBob, where in SC are you? I am in Charlotte and have not found a whole out of XJ members in the forum.

 

intake valve #1 comes in at .127 with a shim measurement of 2.54. if i dropped in a new 2.55 it would bring it up to .137 unless I'm not understanding the math.. same with #2 which has a 2.60 measuring @ 2.59.

 

@ ecologito I'm in Columbia

 

man its cold

 

you have it backwards. the thicker the shim the tighter the clearance.

CN

 

Correct.

Plus you're WAYYY overthinking it.

DROP the .00X of a millimeter; and go by what's printed on the shim. A 260 is a 260 even if it's actually a 2.59. (As long as it's not a 255.) The tolerances aren't THAT tight here; .05 of a millimeter is tight enough. Remember that's .00197" (approx. two thousandths) which is tiny.

This isn't rocket science. Spec is .11 ~15mm intake; .16 ~ .20mm exhaust. Shims come in .05mm sizes; not .005mm.

If intake #1 is at .12mm, it's in spec. Move on. If you go to all the trouble to make it .13mm, it's still in spec, you're changing shims for nothing.

Worry about the ones that are too tight; and fit whatever size shim brings them in spec. Swapping a fat 260 for a skinny 260 (or vice-versa) is counterproductive.

 

AB,

Do you have a manual? There should be a chart in there that will tell you what shim is needed to bring any particular valve in spec. Shims are measured in .05mm increments so your 2.54mm measurement is actually 2.55mm. As Fitz explained, with your feeler .127mm rounded is .13mm (in spec). And as Cyclenoob explained if you go down one size to get more loose with a 2.50mm shim you would take .13mm + .05mm = .18mm (not in spec for intake which is .11mm ~ .15mm). Remember, a little bit loose, meaning in spec, but not the next feeler size loose is okay. Anything tighter than in spec is bad, bad, bad. Thinner shims = more loose and thicker shims = more tight. Hope this helps.

Roc

 

if your familiar with spreadsheets, a member mad this a while ago
shim calculator
i forget who it was but it's a nice thing.
plug in your numbers and post the results, somebody will check them. i'am all shimmed out