Rebuild questions

First off, I am new here so let me know if you have suggestions for future posts!

I recently purchased a 1982 Yamaha XJ550 Maxim, and have a few mechanical questions. I dont know the actual mileage of the bike, it was laid down at some point (found out after purchase, not happy) and gauges where replaced from a bike with 58K miles. most of the damage was repaired, new tank and such, a few things still need fixed, found a couple air fins on the engine were broken off. Last time I look at a bike at night under gas station lighting....
1. to make this bike a bit more highway friendly, I was thinking of switching up my sprockets, both front and back. I did an online calculator and found that I would need +3 on front and -3 on back to get my cruising speed at 4k RPM up to what I would like. So far I have only found +1 front and -1 rear, do they make anything bigger than this?
2. I was wondering would a 6 speed transmission from a 1983 xj550 work to swap out? Currently it is a 5 speed that "red lines" at 60 MPH which puts me at roughly 4k rpm.
3. Would a gauge pod from a 1982 Seca fit on this bike or would it give me inaccurate readings? I think my current gauges are slightly off, that or I actually did get 15 mpg riding around town last week.
4. Is there any major issues this year of bike has that I should be watching out for?

On a side note, today the bike started sputtering whenever I took off in 1st, but would rev fine in neutral and other than 1st it didnt sputter at all regardless of RPM. It also not seems to stick at idling at about 2900 RPM. My thought was something in the carbs? I am running 91 octane and have ran a bit of Sea Foam through it to clean things out. Up till now the bike ran perfectly, lots of power, no lag.

Also, I am looking for others around Moscow, Idaho who ride.

 

You definitely need new gauges. These bikes redline well over 4K rpm.

Get a manual
Check the valve shims.

Then, to answer your questions:
1: Check out the XJ4Ever catalog. All the parts you need are there, and Len is great to work with. 16tooth front and 45t rear is standard.
2: This is a 6 speed bike. Are you sure the shifter isn't just shifting hard? 1st is below neutral, the other 5 gears are above neutral.
3: You should definitely get better than 15mpg. i got about 55 last year. I think your gauges are out.
4: Go to the XJ4Ever section of the forum and check out the Information Overload Hour. And get a manual.

And of course, research lots and ask questions!

Happy Wrenching

 

Oh, and i'm not as familiar with the differences between the Maxim and Seca, but I'm pretty sure an 82 Seca gauges would fit on your bike. One of thr more experienced guys around here probably knows better.

 

I have the full factory manual for the bike, but my knowledge mostly applies to cars, not bikes, I know they are similar, just dont want to break anything.
The speedometer redlines at 60, the RPM gauge redlines at 9+. I read that this year of bike was built for speed limits being around 55, then in 83 they moved them up so these bikes where geared lower. Ive looked in the forum here and everywhere else trying to find a more drastic change on the front gearing, at least an 18, and at least a 43 for the back, I can only find 17 front and 44 rear.

 

Hey c.mann... My sister lives there... Mom in post falls. Lol.

Not a pro but think that the 82-83 550's maxim are for the most part the same.

My bike has a speedometer that reads top speed 85 mph. Pretty sure top speed is 115 mph. You should be able to do 50-60 in 3rd gear. Something doesn't sound right.???

 

You got some weird gauges? Mine reads higher for sure. And in 6th, I cruise at 65mph with about 5k rpm. You sure you aren't starting in 2nd gear?

Not sure where you read that about the gear ratios, I didn't know that they'd do that. But stock is 16/45 and it works fine. Again, the XJ4Ever section and the information overload hour have all you answers.

 

Xjrider, Ill have to run mine up in 3rd and see what RPM I get at 55. I am starting to wonder if the guy before me maybe geared in down for in town riding because this bike definitely wouldn't cruise at 65 at 5000 rpm. Ill do some research and get back to you all when I get back to the bike this next week. Thanks in advance though!
Ill have to go to the xjforever section and get some background info. Ya if I gunned it up to 65 I think I would be topping 7k RPM, this bike is seeming fishy haha. I know I am not starting in 2nd, and am sure I am only shifting up 4 times after starting in 1st, wondering if a gear is stuck, I have been being gentle since the bike is new to me and I didnt want to break anything off the bat, but ill try getting it into 6th at a stop. Thanks!

 

Google it
http://www.motorcyclespecs.co.za/model/ ... _maxim.htm

 

And it's fun to use all 10000 rpm's. They run all day properly tuned.

 

Have you checked valve clearances? You can mess with the carbs and gearing all you want and it's not going to help if the valves aren't in spec.

 

I am doing the valves this Saturday, getting in the tool on Thursday, then measuring on Saturday, if I need new shims it wont be till mid week the following week possibly that I get around to it. My goal is valves then cam tension, then do a carb sync. In your guys opinion is it better to have a shop do the carb sync or get a gauge of my own? after that I want to do brakes, and grease cables and stuff like that before I start changing up the gears, I don't want to put time and money into modification until the bike is well taken care of, I want this thing to last! Thanks for the continuing answers guys! I will let everyone know how it all goes next week!

 

Smart man. In all honesty, I'd just do the sync myself.

A) I don't trust someone else to do it
B) My local Yamaha shop isn't qualified to work on these carbs due to lack of trained individuals and won't touch em.
C) It's so much more a personal experience to do it yourself, despite the occasional headache.

 

Do all you can yourself. Don't trust a shop. The only time I take my bike to a shop is for state inspection or tire mounting. And it makes me feel all warm and fuzzy when I tell people "I did that".

 

Back to the whole gearing and RPM thing for a sec.

The 550s, '81 ~ '83 are essentially mechanically all the same; they all have 6-speed gearboxes.

"Cruising" speed for an XJ, no matter what displacement, is around 5K rpm. Your 550 should be able to pull redline (9500 for the Maxim, 10K for the Seca) in all six gears without struggling; and in the first 4 almost as quickly as you can shift. The powerband doesn't even get serious until it hits 6Krpm; then it makes more power all the way to redline. You can run a properly tuned 550 at 6K or 7K RPM all day without issue.

Once properly tuned, I think you'll find the stock gearing friendlier than your initial impression.

The shifter drum and "mousetrap" on the 550s can occasionally have issues like the screw backing out of the center of the drum or a broken/missing dowel pin. The shift mechanism on the 550 is on the other side (RH) of the bike, behind the clutch.

You need a service manual; the factory 550 book is the one for the XJ550RH Seca; there is a Maxim supplement but all it has are specification differences. All of the service procedures are in the RH book. The aftermarket book for the 550s is by Clymer; and while decent it has a lot of omissions and some rather entertaining mis-information.

Here's a link to a good parts fiche: http://www.yamahapartshouse.com/oempart ... ycle/parts

Valve adjustment: http://xjbikes.com/Forums/viewtopic/t=14827.html

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

Mikuni breakdown: http://xjbikes.com/Forums/viewtopic/t=31061.html

Float levels: http://www.xj4ever.com/setting%20fuel%20levels.pdf

The 550's unique clutch innards: http://xjbikes.com/Forums/viewtopic/t=29541.html

SAFETY ISSUE: http://xjbikes.com/Forums/viewtopic/t=15874.html

Rear wheel bearings: http://xjbikes.com/Forums/viewtopic/t=35134.html

 

C.Mann,

Welcome to the club. Have you done a compression test? You need to know the plant status. Once you know the plant is good you can move on to the other scheduled maintenance items as advised and outlined in your manual. IMO I wouldn't be concerned with changing sprockets and re-gearing and such. As others have advised...get it running to form (it's not) and see how that feels to you. XJ series bikes have surprising "getty up" when they are properly dialed in. Hope this helps.

Roc

 

So all I had time for today is a compression test, from left to right while sitting on the bike - 140, 122, 127, 138. Seems like all are within a decent range, I am hoping a valve adjustment might bring them closer together? Got snowed out before I could get a valve check. Novice question, will removing the left side crank cover to do the valves drain the oil?

 

Interesting results from a 550.

Definitely want to get the valves in spec and re-test.

No, the ignition cover has nothing behind it but the ignition.

Have a peek: http://xjbikes.com/Forums/viewtopic/t=14827.html

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

 

That guide will help a ton, I will try and get to that Monday afternoon. It will be a bit to ship in new shims, but I am hoping to get those numbers near 140 down a bit.
Thanks you!