25K checkup

What are the main things to check for the 25k check-up

 

Need to know which bike.

 

81 650 XJ MAXIM

 

Well I'm not a "know it all" or anything, but I think it would be about the same as getting an unknown bike; do a once over.

Steering bearings, grease and check. Look at rear brake shoes, grease splines, check wheel bearings, bleed brakes, check Alt. brushes, replace 25 year old fuel lines, filters, take up slack in timing chain, check valve clearance, inspect tires, service battery, plugs, sync and tune, gravity feed lube all cables, fork oil? That should keep ya busy.

 

Check valve clearances, change final drive gear oil, check & clean air filter, check & repack wheel & swingarm bearings, lube control cables including speedo drive cable and change front fork oil. Note, leave the swingarm bearings alone until you know how to properly preload the bearings. This is not hard but very safety critical. Improper loading can induce moderate to severe weaving at speed.

 

it's the valve, cam and timing checking that was woundering about.
Never done it on a bike before (pleanty of cars)
I have a manual I just want to make sure of what I'm doing before I do it
I think before I do. Safer that way. I might seem to be a little
over cautious on this, but I'm not going to ruin this engine.

 

You are not being overcautious, you are acting intelligently and responsibly. I commend you for that. There have been several valve shim threads here so do a search on it. The cam timing usually doesn't need checking. If it is off it will usually be a camchain or tensioner problem. Yamaha originally had a valve check time of 17k miles but extended it to 25k after a few years of bikes in the field, so yours is right on time.

 

The Battery, Brakes, Valve Clearances, re-pack the Headset Bearings and put a wrench or an oil can on everything else.

Look in the Manual for recommended schedules service and do everything you haven't done of know hasn't been done.

At the very least ... know what your Valve Clearances are so you can either adjust them or leave them alone.

At 25,000 Miles you might fine one or two tight Exhaust Valves.
Those you need to deal with right away.

 

Thanks for the info. I got some info last night that to me doesn't sound too far off. I'm been saying that I've been running rich because of the fuel
odor from my exhaust, but yet when I turned down my air mixture I started back firing. I was told to change my coil packs (mine are still the original ones) that if the spark is not strong enough it won't burn the gas fast enough. To me this makes alot of since even though there is only 25K
on the bike if anybody out there in the real world had a car that was 20 years plus old we would have changed the wires at least once or twice if not more. Well we just can't change the wires now can we? I'm going to check pricing at the dealer, but if makes since to anybody else please let me know als does anybody know if there is a good after market coil pack
or if I should stick with the OEM.

 

IF you are going to replace the coils, Dyna S would probably be your best bet and will set you back about $135. The air adjustment screw only changes the idle fuel mixture and not the operating air:fuel mixture and the jets control operating mixtures. Take your bike for a nice ride around a couple blocks and as you come down your street, turn off the key and coast home. Pull out the spark plugs and see how you are running. The porcelin should be a light tan color. Black/sooty indicates a rich running condition and an off white color indicates a lean condition.

 

Thanks for the info. I already know that my plugs are wet when I pulled them about 2 weeks ago after about a 40 mile ride.
The $135 for the coil pack is that for 2 or each? I know the dealer wants
$102 each but like cars I'm thinking there are better after market ingnition
system parts then the OEM.

 

Before you go and spend money on coils, check them out to see if they need replacing. Most issues are with corrosion where the plugs join up with the coil wires. Hold the spark plug wire and just turn the plug cap counter clock wise until it turns off the plug wire.

You can buy aftermarket plug caps. Much cheaper than coils.

Also check other parts of the ignition where you have a connector. Use a contact cleaner and make sure they have continuity.

My guess is your rich condition is carb related not plug related.

 

If this bike has bees sitting for ages,, you might want to lift the tank and undo the two plastic plug-in's where the Coils plug into the Wiring Harness and spray them with Electric Contact Cleaner.

Especially, if the Bike was stored outsidie or in a non-heated garage. Over time the contacts get oxidized and will set-up a high resistance in the connection.

If you did Carb work, its not uncommon to have the Bike run Rich.
Without a Colortune or a Meter to tell you how the Hole is firing the Pilot Screw is adjusted too Rich trying to Pre-set a Factory Condition.

You just have to remember that the Pilot Screw is Ultra Fine-threaded for a reason.
It doesn't take much of a turning of it to get it right. If the Bike is running a small tweak of a couple of degrees might be all that's necessary.
When you get a Colortune, tune it for the back-side of the Blue.

Go through the Blue and tune back into it. That will give you the Mixture to have a good Idle and sustain Ignition when you open the Throttles and the rush of Non-fuel bearing air precedes the Main Jet Supply for an instant or two.

 

Ok I pulled the plugs and to my suprise #2, 3, & 4 looked perfect
light tan in color. #2 had just a hint of black.
#1 did have a good coat of carbon on it so I turned the mixture screw it just a tad.
I need to reseat my carbs back into the airbox boots before I can say it is perfect though I know this will make it run on the lean side if everything isn't sealed up good. For some reason when I put them back on this time it's like the boots are too short and
aren't going on the carbs right. I am missing a bolt on the aribox so that
might be why it's not lining up but this should be a easy fix. I'm just glad
that I'm almost there and this is telling me my coils are good (saves me $200).
Thanks again to everybody that responed to my post

 

Kerst:

The AirBox Boots aren't all the same. The two outboard ones have a different little shape to them as the ones that are to the middle two Crabs.

If you mixed them up. They won't fit and you'll have to pull all four and eyeball them sitting on the Horns that are on the inside of the airbox side.

Set the four on a flat surface with the Horns flat to the surface.
Look for two that are "Angled"
Those are the ourborar ones.
Look along the "Channel Grooves" for a "Tab Marker"
Place the Tab Marker facing you.

There should be one angled to the Left.
One angled to the Right
Two practically straight.

The two which are "Bent" are for the Outside Carbs
The straighter ones in the middle.

The Tab Markers get lined-up with receiving tips on the airbox.
Absent the tips ... put the Tabs at 12 O'Clock and you got it!

 

I know you have told me before that they were differant.
I have looked into getting a new set and the dealer and Charcol who sells
the parts here even told me they were all the same and have the same part number. How ever I am going to take them all off again and look at them, besides I want to change out the clamps with a differant style.