Maxim-ising her potential

Hey wizards

I've spent the last month of my final semester doing nothing but watching motorcycle resto videos, reading and daydreaming about returning to my bike. So thank you, motorcycles, for my final grade.

So on my days off I'm returning to my parent's place to use the sweet garage because I want my 82 650 to be my summer commuter, and I wanted to track my progress on here, share what I learn and whatnot.

I started off with the carbs, cleaning them all, they're actually in really good shape. pilot tube down into the float bowl was a little clogged, but I worked that out. The pistons clunk like they work for the mafia, and the diaphrams are holding out despite their age. They're still fairly flexible, I'd say they have about half their life yet.

The tank was rusty so I bought a bunch of vinegar, and I've started soaking the tank. I've thrown in some nuts and bolts, shaken it around a bunch of times and the excrement was...very rust colored. They're soaking as we speak.

The end of last season, I had AWFUL compression so it started off as a piston ring replacement. I don't remember the exact numbers but they were something ridiculous: 80, 40, 90, 60. Something similar.
Due to the oil in the cylinder compression test, I determined it was the rings. I knew rings were pricey, and thought instead I'd go off ebay. I found a cheap set of JUGS AND pistons, with a full set of rings off a bike that only had 5k on the odo. They come, they're great.. but the jugs were off a bike with YICS. Which mine doesn't have.
So I used the pistons and the rings like I thought was okay, but I didn't measure the ring gap.
I'm putting on the jugs, and one of the rings snaps. Great. So I had to use one of the old rings on one of the cylinders. Tough. I made sure the gaps were offset from eachother, and sucked up my failure, fished the pieces of broken ring out of the crankcase, made SURE they were all the pieces that made up the broken ring, mounted the new gaskets and o rings, and sealed the deal.
And she wouldn't start all of a sudden.

Electrics are fine, the shims need re-shimming, and the carbs were cleaned. She was running before i took apart everything, and wasn't sure what was going on.

I have two valves that are at zero gap, which is awful, yes, but all was running fine before, and I do have new shims on the way, so I'm not sure why all of a sudden it doesn't work.
The battery is crap, so I hooked it up to a fresh one and still nothing. Cranks, but doesn't spark. we pulled the plugs out and grounded them, the spark looks weak. I'll be buying new iridium plugs soon as my next paycheck comes in, this is unfortunately my life right now: my motorcycle eating all of my cash, but I love it.

So I did a compression test on the (mostly) new rings, and i've got 110, 60, 110, 115.
I'll be pulling off the jugs after i finish up this post, and measuring the ring gaps.

So after that long-winded schpeel, my question is this: Why was she running fine before, do you think? Compression was way worse and yet here I am.
Could it be that I put the rings in upside-down? I was a bit careless, and didn't pay attention to that specific detail.
Thanks to everyone and anyone who read this far for your attention and your advice.

I want this bike to be a consistent machine, and after jetting, shimming and synching, I'm confident she will be.

Ride well

 

things to check ...in no particular order (you may have completed them, I'm just giving you a list)

fuel level in each carb
Make sure timing marks are lining up (something I missed on my first rebuild and bent some valves)
fully charged battery
make sure spark plugs are properly gapped
valves shimmed properly (looks like you're in the process)
Check for fouled plugs

Once you are able to get the bike to run the psi on #2 cylinder may come up, re-check the psi after about 100 miles or so.

 

Thanks, Tcoop.


Most of these things will come cascading in as "completed" at about the same time. I have to work in three-day spurts, so I smash out many things at once, and as parts come together, problems will be solved one after another.
I've bought new float bowls to replace the ones which had stripped drain screws, so I can actually use an accurate, sight-level method, instead of guessing where the bowls fill based off of a measurement from the inside.
Timing marks are aligned, I made sure when I was putting the camshafts back on to take double care -one of the things i ensured I would do - when I was re-assembling the head.
The battery used was a fully charged, fully functioning one off a car, for even more cranks, if i needed them or simply wanted to burn out the starter...
I will be buying new plugs soon as the next paycheck comes in.
And as for the fouled plugs...

I took off the head again, and found this sort of thing sitting at the edges of TDC, as well as on the top portion of the pistons.





One has a stuck ring, closed shut, and basically flush with the piston body, in theory, not doing anything.

There was definite charring down the sides of the piston, past that ring, as well as a little bit of trickle of residue on another piston's wall. The black stuff was only in the pistons which have zero tolerance, which tells me that they- the exhaust valves - are barely opening and so not all of the exhaust gasses are getting out. The bike "chugs" when I crank her over, and i'll take the exhaust headers off again to make sure I don't have a set of stuck valves completely shut.

 

Some blowby is normal. The gunk you have is carbon buildup, and can be cleaned off with Seafoam, or a 50/50 mix of ATF and Acetone. Your cylinder walls look good too. I can't see the image of the piston. The images aren't linked correctly and whichever missing image link I click on will only load either the cylinder pic, or the gunk on your finger. To link images copy the image address, click the mountians icon on this page, and paste the image address into the pp-up window, then click insert.

 

I've just figured out the image posting system here, I think.

This first one is piston #2, with all of its stuck-piston glory on display. It was a doozy to unstick, And I have no idea why, but when I tried to remove it, I had to wedge the edge of a razor, and carefully shimmy some space inbetween the ring ends. Then, after continued difficulty, I heated the crown of the piston with a blowtorch and, after that, was able to shimmy it out without much difficulty.


This be the walls of that cylinder, of the stuck ring. Clearly, staining due to a bunch of blowby from a dysfunctional ring. I'll be honing these cylinders very lightly, just to de-glaze and give these (relatively new) rings a seat. Rings have 3,000 kms on them, and are crisp as hell, where the bores of the jugs have 26,000. I pushed down one ring into the bore, down to its lowest functioning point, and am still well within the serviceable limit before I need to oversize.

I cleaned the heads as best as I could, and I THINK I got all the appropriate shims, from what i can tell by my measurements. The beauty of it is that I won't be able to tell until the head is back on the bike.

Now, I've torn the paper gasket, and I've been told that there is a non-silicone sealant I can use by the guy on the honda forums. I'm also going to be re-crushing the top gasket for cost and the sheer fact that:
1. I never ignited using it, though it did experience some (lacklustre) pressure
2. My trusty Yamaha service guy said some technicians double-crush their gaskets. It's still in very good shape, so I'm not worried.

Shout out to Yamaha in Vancouver for having the shims I needed, and most of the jets, too.

So, tomorrow, from early morning:
1. Hone
2. Sealant and paper gasket fixing.
3. banging out an aluminum box for my delicious new battery
4. New spark plugs
5. Friend arrives to help me guide the pistons into their bores without breaking any rings.
6. High-fives, hugs and pizza.
7. Header assembly, cams on and clearances checked
8. Celebration
9. Float levels
10. Continue de-rusting the tank with vinegar... until I return on sunday, my next day off...

11. Insurance and ignition.

 

Gentlemen. Gentlewomen. My quest for ignition continues.
I got to step 10. No ignition, though the trials have been many, I do not give up, but I am discouraged and need to come to you wizards again.

I have a few thoughts as to why my bike isn't running yet. Please, if you have any that applies, share your wisdom.
1. The starter motor is worn out. I've cranked it many times, never for longer than a few seconds, but I fear she might be worn out. I'll be checking that out.
2. SOMEthing I've done when rearranging the starter circuit has dislodged a connection somewhere minute, the sodering coming loose perhaps, underneath the electrical tape I've insulated it with, or one of the connectors I've crimped on is ... somehow not connecting. I'll be going through my custom harness thuroughly, to ensure it isn't this. (should've bought a used one off ebay, but I was determined to learn)
...I wonder if the use of high-guage wire is a problem - in my nervousness to ensure Id on't mess anything up, I used a thicker guage... i think it was 12... Nothing outrageous, but a little larger. I was wondering if over time this might put uneccessary strain on some electrical component like the regulator or any other component. I muse this because she already ran with this harness before she didn't, and now I'm wondering that the thicker guage was too much... but it seems ridiculous.
3. I may have crossed some wires somewhere in the circuit when putting the harness back together... at the time I couldn't afford multiple colors of cable, so I used.... well, mostly red cables... complicating my system.
4. There's something with the coils igniting the wrong cylinders at the wrong time, I followed the reassembly of the cams to a T, so all the timing should be brilliant, but I'm still nervous. All my demons are electrical, and make me nervous and wary.

So hopefully a short journey is ahead of me, and I ask the gods of physics and chemistry to be with me.

It's my first day off work in a week, and I'm back at my dad's place out of town to take advantage of a well-stocked garage, where I'm keeping my bike. A tiring quest out of town on a couple busses, not leaving time to eat much, sleeping very little, filling my day with motorcycle troubleshooting. A wonderful predicament to have and a great return for the investment of all my free time. But I want to get riding! The hunger is great, and I feel like I'm letting the Japanese engineers who made my bike down if I'm not riding her, because this wonderous feat of engineering is just sitting under the patio.

I spent an exhausting and fuel-intoxicating amount of time adjusting the float height levels, made infuriating when I found a simpler way. But fuel levels are now perfect.
I've replaced plugs, the battery, and bored the cylinders to seat the piston rings. I've re-shimmed everything.
I've re-done the wiring harness with my own wires to ensure that there's nothing electrical the matter, and arranged all electrical components into a tight little package in a little box under the seat pan which I bent out of aluminum.

And the starter motor chugs away and the bike doesn't fire.

The starter motor cranks at a fine speed, it seems, and the coils' resistances are in spec.
I have no idea why the bike isn't running, but I will pursue. Thanks for reading and any advice you have.

 

I just had another thought:

Could I have tightened the camshaft caps too tight, forcing everything to be under much more tension than is required because the cams are hard to rotate? I had a torque wrench, but it was massive and I didn't have a bit that would fit the tool and the cap bolts. So I got the torque value through feel.

I don't think this could be an issue, but I have been wrong before.

 

The cam caps NEED to be set to the correct torque. Bearing distortion (among other issues) can result.

That is not related to the starter problem (rebuild it), but it will cause you trouble later on if not addressed now.

 

Thanks for the tip, k-moe.
Turns out the starter is just about perfect, brecause...

She fires up instantly!

I'm so excited to say that my spring will be spent maintaining AND riding my beast because after loads of hours, scars and tense neck muscles, the final issue was a crossed wire and a lose connection. Somewhere along the way in my tired state, I misread the diagram and plugged the wires for the coils into the reverse spots on the ignitor unit. I had to change to spade connectors from my local hardware store, as the connection that came with the bike was all brittle and disgusting. So I swapped those around and now she has bright, blue sparks, and turns over right away.

Thanks for all your help, guys, that was quite the journey, but it's taught me so much. I'm going to be present when I ride, because when I was present while I was wrenching, that's when things went well. I'm very grateful for all of your wisdom that you share on here, guys, and I'll think of you while I throw my leg over for the first ride of the season tomorrow.

Ride well.
And may the force be with you.

 

Good luck I'm enjoying the prose and your journey..

 

Gentlemen...
I may have gotten a little too excited.
In breaking in the new rings, and the honed cylinders, I may have taken it too hard too fast. The second run, at 5k max rpm, led to a bunch of smoke. This was due to oil sneaking out of the head cover gasket, because of... awfully loose bolts. Rectified, the next run gave me smoke out of the crankcase breather... which I assumed was the rings still breaking in, not completely sealed to the walls. I will not deny anything.. within the first 100k, I worked her up to 8000 rpm... I did this GRADUALLY, of course, over a series of runs... but it was still way too soon, now that I think about it. I've taken a couple one hour runs, the end of which, I noticed smoke out of the breather, and then a bit of oil on the block. I feel dumb... but I just was so adrenalized by this fantastic engine. It's amazing that it's over thirty years old. It's so sporty and fun. If I was too excited in the beginning, I have round the respect for the bike which I had in the beginning, which unfortunately I lost a bit in my excitement to actually ride her.

Now, the questions I have are few:
1. Will there still be a bit of smoke, for the first 500 km? I've been following the break-in proceedure on the information overload hour, albeit, not too diligently, and it doesn't say anything about that.
2. Am I looking at another re-hone? My rings still have a bit of servicable gap to handle it.
3. Will this garner me shame from you all forever?
4. Can I redeem myself through promising that I'll treat her respectfully, lack of sleep and lack of finance be damned.

My first rides on my Maxim, Molly will be forever ingrained in my being as something fantastic. I feel so fortunate to own such a great bike, a little bit of guilt for letting my emotions get the better of me, and a whole bunch of inspiration and invigoration for the future to come.

Much love, and ride well

 

Ride it and keep track of oil consumption over the summer. It can take a while for new rings to fully seat.

 

You've made my heart lighter, k-moe. With even the hope that perhaps my 4 or 5 brief but extremely memorable trips to a screaming 8,000rpm did not hurt my beautiful example of Japanese engineering magic.

That being said, gentle riding continues.

The smoke from the breather has lessened, and I no longer have a leak from the head gasket because I tightened the header bolts.