1986 fz 600 purgatory

[James Crispy]

Hey all !

This summer was time for my first bike and I fell for an 86 FZ 600.

Started with this video:

https://www.youtube.com/watch?v=bY45PIhzKs4&list=PLW5ff6L-THDSXxwBNhbynLr9IjlwOJp3u&index=3

I went and saw the bike and being a little too excited / a bit naive, I bought this sellers story of "near mint". It stalled out on my first ride home. The bike would only last for about 10 mins before dying completed and I was left stranded multiple times. Not a great start with my first bike. (

So I went over the bike found all kinds of garbage. Missing bolts everywhere, oil leak, hacked up electrical, gaskets made out cereal box, left side carb boots on right side etc etc. A real **** show.

I order a bunch of parts and got to work on my new PROJECT BIKE (sigh).

Here's what I did:

- new battery
- replaced rectifier and solenoid
- fixed hacked wiring around fuse box
- replaced frayed positive lead to battery
- cleaned and coated badly rusted gas tank
- replaced fuel line, added fuel filter
- cleaned pet****
- removed carbs and cleaned
- replaced pilot jets
- replaced carb / manifold boots / added gaskets
- replaced broken airbox joint clamp
- fixed broken fairing attachments
- replaced random fairing bolts with all OEM

It was a bit nerve wracking putting the freshly cleaned carbs in but after some tinkering and swearing, I tried to start it.

IT WORKED!!

A quick carb sync and it was running great. Finally out riding. Smooth and awesome. Totally overjoyed!!

Two days later, I push the bike a little bit. Took it up to 9000 rpm shifting into 2nd, then 9000 shifting into 3rd aaaaand POP !! Something popped. RPM flatlined. Bike dead on side of road.

$260 for a tow home and there it sits.

Whatever is wrong now is beyond my newbie knowledge. It turns over but will not fire. There were a couple of bangs out of the muffler right after "the incident" when I tried to start it again.

Any idea what the issue could be now?

 

[Hellgate]

Great job! The FZ600 is a fun bike.

Have your checked the cam chain tensioner? Are the valves adjusted to spec?

 

[Motogiro]

:welcome: to the forum! I agree with Hellgate. I would first think there may be a valve timing problem. I would first check to see if you have spark and after that make sure you're getting fuel. If those seem to be okay then a compression test is in order. If it fails the compression test you may have lost the timing chain or jumped a tooth on the cams. Most of these engines do not free wheel when out of time with the valve train and the pistons kiss the valves. If this happens it will be a more costly ordeal but sometimes a challenge builds a better person. Some thrive on these challenges!

 

[James Crispy]

Hellgate, I have not checked those things. Because of the condition of the other things I fixed I suspect I'll need to adjust both. Was really hoping I would not have to go there until winter. (Read another post about how a fz600 owner spent most of his time fixing rather than riding and I'm fearing the same fate)

Would either of those things really cause the whole engine to shut down like that?

hey Motogiro!

Yes. I checked for spark and fuel. Seems good there so on to the next tests.... I'm down for a challenge it's just a little too soon for the next one! Summer's a wastin'

 

[Hellgate]

I'm thinking the cam chain was so loose that it may have jumped a tooth. Granted it's hard to do but can happen. The tensioner is on the outside of the motor so you don't to take the motor apart.

Keep in mind your bike is 30 years old and the PO made cardboard gaskets. You've got some work in front of you.

 

[James Crispy]

Ha. Oh Great. :rockon:


I will step further into this black hole over the next few days. Will keep you posted....

 

[Hellgate]

Good, looking forward to hear what you learn.

 

[James Crispy]

Started the process of checking the valve clearance / timing etc and came across this:



That doesn't look right. Also the cap was missing one of the bolts.

Here's inside:



That also doesn't look right. Of course it's the $410 base pickup. :Flash:
I suppose it came loose and got smacked.

Close up:

 

[James Crispy]

Found some on ebay ranging from $35 - $200.

Ordered.

 

[TownsendsFJR1300]

Welcome to the forum and your work in progress.

That broken case is not good. At least its not a major stress part, a good epoxy may help you there.

Why that sensor came loose/broke off, is what I'd like to know..


With the cam chain, its in the middle of the engine, between cylinders 2 & 3 ; 1986 Yamaha FZ600S Camshaft Chain | Babbitts Online

While your waiting on your parts, I agree checking the valves and cam timing would be a good thing. Just to make sure the chain didn't jump a tooth and bend any valves...

The bike sounded pretty good (prior to stopping) but for a more in depth check a leak down test on each cylinder would tell you alot more about the health of the engine itself.

This is the tester I use, ( https://www.otctools.com/products/cylinder-leakage-tester-kit )not expensive and works really well. You do need a small air compressor to operate it .


Not that it matters now, but it looks the front edge /cover took a hard smack and the cover (probably been replaced) broke off a piece of the block..It looks like its out on backwards or something...You want to try flipping that around so it fits and use the epoxy. It doesn't appear that area has oil in it so that's a good thing

 

[Motogiro]

Almost looks like there was hot solder flying around in there. Check that rotor carefully. It may not being in the same position on the shaft. There should be a key or flat it keeps in place it may have moved on the shaft if there was a mechanical interference.

Sent from Moto's Motorola

 

[James Crispy]

Hey Townsends. For the 3 days I had it running right, it was amazing.

Yea. Weird one. I would guess that sensor came loose because they seem to be only glued onto that plate which is then screwed into place. 30 years, a ton of heat, revving up to 9000....POP. Maybe?

The block was probably broken at the same time the small dent in the frame happened :disapprove: . Epoxy will fix it.

At least I found something concrete.

Valves / cam chain look ok:



Checked all the valve clearances.


Intake valve clearance specs are .11 - .15mm

Valve 01) .178
Valve 02) .076
Valve 03) .076
Valve 04) .229

Exhaust valve clearance specs are .16 - .20 mm

Valve 01) .102
Valve 02) .102
Valve 03) .127
Valve 04) .102

They are all off.

 

[TownsendsFJR1300]

Thanks for the update. Some pretty wide values with the valves. It'll run a bit better once those are in spec and re-synced.

Were you able to check the timing between the cam's and crank, just to make sure all's lined up. (keep and chain slack at the back "run" of the chain-you probably already know this)

Was it like a loctite holding that sensor on and is the screw hole NOT stripped (for the sensor)?

 

[Hellgate]

Thank goodness for JB Weld!

Good luck with the repairs.

It's really a nice bike. A buddy and I used to endurance race one back in the '80's. It was pretty fast and had very good handling for the time. It's one of my favorite body styles too. I like the dual headlights and the block seat.

 

[James Crispy]

The look of the bike is amazing. That's what got me. I love the dual round headlights as well. Also ordered a rear seat cowl to finish that line at the back of the bike.

It's just a generic looking glue (slightly yellowed) that was holding the sensor on. The screws that hold the magnetic plate down are ok. However there does seem to be another missing part as Motorgiro suggested. The ignition timing pointer screw.

I found a guy who is parting one out nearby. I'm going to pillage the thing tonight.

Also, there is a guy who is selling a full one for cheap because it's not running. Apparently it just needs the fresh carbs to be put in. I'm concerned about a bike that's been sitting for 15 years without running, even if it only has 15,000 kms on the engine. What do you think?

RE: Cam / crank timing. Any more info you could offer on that? I don't know much about that particular process.

 

[TownsendsFJR1300]

Heck, if the price is right and you have room, a spare parts bike would be nice..


Re the cam timing.

I'm not exactly how the marks are on your bike BUT, the crankshaft (again not which side) should have a mark for TDC (Top Dead Center) for #1 cylinder.

The cams should each have a mark on each sprocket (probably a dot). With the crank mark spot on TDC, the gear marks usually line up with the SURFACE of the head. Wether they face in or out, I don't know, but it should be obvious. If one cam is off visibly by a tooth or so, and the marks don't line up, the engine jumped time.

****Mark sure when checking the marks, you slowly, by hand, turn the engine clockwise(from the right side of the bike/brake pedal side). You want the FRONT RUN of the cam chain TAUGHT when checking marks. The tensioner obviously takes up the chain slop at the rear..

With the valve cover off, you should see them fairly easily.

Actually, once you start re-shimming cams for correct clearances, they'll both be coming out... You NEED to know how they line up. A shop manual would help but the above process should get you going. The correct torque for the cam retainer caps are also needed..

 

[James Crispy]

Awesome thanks.

 

[James Crispy]

Some good pickings off that junked FZ 600.



This was a neat fairing, apparently a Yamaha of some kind?



So, I got a bunch of scarce screws, spark plug cables, starter, alternator brushes, and the same coil that just blew on me.

Speaking of which, here's that dark moment from this area of 1986 FZ 600 purgatory:

 

[James Crispy]

I checked the cam timing. All good there. Cams still in sync.

Shims on the way....so since it's all opened up, like you said, good time to check the torque on the cylinder head bolts.

And now I step even deeper into this. A Gremlin on every level it seems.







This one right here. The number 1 bolt. Spinning.

Pull out the bolt and:



:cheer:

Stripped.

 

[TownsendsFJR1300]

Well, almost 30 years of folks dinking with it. Nothing a heli coil can't fix.

I'd leave the head on as a guide when drilling(maybe some tape around the upper end of the bit so it doesn't scruff the head).

Same when tapping the hole.

It probably wouldn't be a bad idea to pull the head eventually and check for straightness and a new head gasket too..


BTW, I never mentioned re-torquing the head bolts, its usually NOT needed, but glad you found it..