Another new project... Another new forum...

Hidey Ho there fellas,

A deal on an '86 xj700 fell into my lap 2 days ago, and after going over the bike I am going to have some questions when it comes time to start wrenching. This will be my 2nd Maxim. My first was an '82 xj1100.
One of the worst mistakes of my life was trading it off for an 82 F150 in '06.
My name is Chris, and I'm addicted to making broken things... not broken anymore.
I spend my professional life making big pieces of metal into smaller pieces of metal. Most of the pieces of metal I work with become oil & gas tools by the time I have finished making them. But of course... being a machinist- some of my most serious hobbies include firearms, and motorcycles.

The 'new' bike seems to be in fairly decent condition... the factory paint isn't too bad and there is hardly any rust for being so close to the coast. It does have a few little issues but I don't foresee them being too difficult to rectify. The piston is stuck in the master cylinder.. carbs need cleaned and tuned... probably could use a fresh oil change... but test riding this 700 vs. how I remember my 1100 was like night and day. The 700 is a total beast! I always had issues on the 1100 with something in the driveline slipping when I would try getting on it. The new one is solid as a rock.

I do have a coupe concerns with the rotating assembly...
Can someone point me in the direction of a procedure to safely tighten the timing chain? I kinda get the feeling it is loose.

I am also interested in recommendations for what oil these things really like in the crank case.
full synthetic a good idea?

 

Click on and read both of the links in my signature. Welcome aboard.

The cam chain has an automatic adjuster. What makes toy have concerns aboout the chain?

There are very few synthetic oils that will be good for any wet clutch motorcycle (again, info in the links provided).

 

I can hear what almost sounds like chain slapping something in the case... I just can't remember if my 1100 did the same thing... or if it was just louder and I couldn't hear it over the exhaust...

 

That is more likely the primary (really alternator) chain slapping. Pull the shift cover and have a look in the passage that is to the rear of the shift drum. Use a flashlight and see if you can find any chunks of plastic. There is no tensioner on that chain, but there is a guide. It is normal to hear some slap at a low idle, but if it is still slapping above 1,100 RPM the chain guide may be broken.

 

Roger that... it only seems apparent below 1k. I will send a sample of the oil in the case to Blackstone for analysis. Mayhap I could get a good picture of any rotating assy wear by wear metals indicated in the analysis? I have become accustomed to this practice with my diesel patients.

I see quite a bit of spare parts available on flea-bay... and it's getting the tinker bug kinda hungry. can you point me in the direction of the fellas who play with the outer limits of modification and performance enhancements? Thinking along the lines of boring a set of jugs and making some pistons to stuff in 'em. Diesel performance is crazy expensive... and complicated. Something like this should be fun, simple... and best.. cheap!

I ran the motor up to normal operating temperature a bit ago and let it settle down... I could almost hear it flushing the varnish out of the jets. Gonna need a carb sync/tune up at a bare minimum. As for the master cylinder - is there a tried and true prefered option for getting the piston unstuck? or would I be ok drilling and tapping for like a 10-32 or maybe a little smaller and build a little slide hammer + ATF/Acetone?

I put it up on the mainstand and ran it through all the gears at idle... everything sounded and looked pretty good except for 5th. Had kind of a buck to it and a fairly pronounced sloppy chain sound to the driveline. I have yet to take it beyond 3rd on the road as I prefer to stay off the highway until it is all legal. 1st through 3rd however in its first 10 minutes running after sitting for an extended period were as stated before... beastly.

 

Let's clear up something first. Do you have an airhead XJ700 or a water-cooled XJ700-X?

An oil analysis will be helpful, but most people don't do one (no clue why).

Carbs: The Church of Clean. Do the whole shebang for peace of mind at the very least.

The master cylinder piston: Remove the banjo bolt and use an air line on the port to pop the piston out. Be mindful of the resulting projectile. You may want to spray some ATF+Acetone or Kroil into it first and let it sit for a few days to loosen up the brake fluid chunks.

A sloppy chain sound under load makes me suspect that the primary chain guide has indeed fallen apart (though on the stand in 5th there isn't much load onthe engine). Drop the oil and look for flakes of steel. If you see any, the most likely cause is the primary chain rubbing on the primary chain oil jet. Also check for plastic as I described earlier. The chain guide brakes down from age and your bike is old enough for that to be happening. Unfortunately the only remedy is to split the cases and replace the guide. This really should be done before the oil nozzle ($99 for a new one) gets worn through and takes out more expensive parts of the engine. Since your plan is to build an oversize engine this won't be extra work for you (I'm assuming that you will have the crank balanced to suit the new rotating assembly).

Chacal (member name, catalog link in the upper right corner of every page) has every available part in stock and ready for shipping. He's be my go-to for anything that I don't want to risk buying used.

 

Great info K-moe. Thank you for jumping in and schoolin me.
It is an air cooled engine. Yes I will balance the crank for the performance build.
Beyond the paperclip/business card trick... is there a need to go more anal with carb syncing?
In its current condition... I can start the engine cold, let it warm up with the idle screw adjusted to high idle... once it reaches operating temp the rpm's climb up pretty high... then i can back off the idle screw and it plays mostly nice. It does seem like it takes a while longer than it should for the rpm's to fall back off though. If I shut it down while warmed up... it does not want to restart without being hooked up to some sort of electron boost. With it on cables it starts pretty much instantly. I had a similar issue with my 1100 years ago that was resolved by a new stator and rotor. It does seem to be charging the battery at least minimally. I need to put my meter on the terminals with it running to make sure its charging...

The first time I got it started it almost seemed like it had a partial miss in one cylinder but that has mostly cleared up.

At the very tippy tops of the fork tubes... are those plugs? or set screws or something? very very rusty... are they replaceable or should I be looking for another set of forks? I have seen a few sets on flea-bay that look decent and aren't too spendy.

 

Oh yes.
Meticulous attention to detail, before during and after carb rebuild.
As Kmoe said a running synch, colortune, verify no vacuum leaks . . . . oh wait, are the valves inspec?
Hope so or else you have to synch again.

 

Have been perusing all the wonderfully documented procedures for taking care of the valve train and the full carb rebuild threads... good stuff in this forum for sure... reminds me of the attention to detail that goes into the tech pages of ford-trucks.com (ford truck enthusiasts forum).
so... first thing will be oil analysis... maybe get a jump on any rotating assy issues...
2nd will be valve shim job
3rd on the list will be carbs

I'm hoping a fresh oil change will yield me the luck some others seem to have found in stopping the starter clutch grindy noises...

keeping fingers crossed that I do not find metal bits in the oil.
Should have pulled the master cylinder this morning and futzed with it today... dismally slow in the oil & gas tools production world down this way lately...

 

Welcome!

 

As an interested novice, what info does the oil analysis provide?

 

An oil analysis will tell you the condition of the oil at the mileage it was changed (basically is it still in spec or not) and will let you see things like the amount and type of metals that are present (this can help identify bearing wear before expensive damage occurs) and the amount of combustion byproducts (this can give you an idea of how well the rings are sealing). Head over to http://www.bobistheoilguy.com if you want to delve into the technical aspects of engine oil.