Won't start after valve adjustment

[Geezer]

I did a bunch of service on my '05 over the winter. Suspension, tires, Uni Air filter, lube the pivot points, and finally adjust the valves. So I had a lot of stuff off the bike and back on without starting it in between.

Now it won't start. I tried the WOT trick a few times. I took the air cleaner out to make sure it wasn't blocking the air flow, and put new plugs in again. The ones in there were new, but came out wet.

I get some smoke out through the air box. Then I stuck my hand over the end of the muffler and it seems to be sucking instead of blowing. I have a Muzzy system with a single muffler.

I replaced the valve shims on three intake and three exhaust valves. Five of the six were tight, not out of spec., but right on the edge, so I replaced them. One exhaust valve was out of spec, on the loose side.

I left the chain on the intake cam gear but the exhaust one came off because I needed to get to that valve shim that is closest to the end of the cam where the chain is. All of the marks lined up after I put it back in and I turned the crank and rechecked the timing marks a couple of times before I put the valve cover back on.

Any ideas? Do I have to pull that valve cover back off? What a PITA.

Thanks.

 

[PapaUtah]

Could be a cam 180 degrees out of spec...ouch.

 

[exskibum]

Could be a cam 180 degrees out of spec...ouch.

That was my first thought, too, except I don't think the symptoms fit 180 camshaft degrees* (which would get you compression stroke and blowing, not sucking at tailpipe). Wouldn't it be more like 90 or 270 camshaft degrees off to have the piston descending on intake or power stroke with the exhaust valves open to create the vacuum on the exhaust pipe? Can the FJR engine do that without doing (ionbeam tested) valve into piston collisions**?

* Following clarifying post below, 180 crankshaft degrees would equal 90 camshaft degrees.

** Apparently, you got lucky with the exhaust valves going from opening to closing only when the piston was not close enough to TDC to collide.

EDIT: after rereading the original post -- I'm going to GUESS that you're 90 camshaft degrees off (late on the exhaust cam timing) with very good karma -- the exhaust valves are opening on the intake stroke along with the intake valves. That's why you're getting wet plugs, vacuum on the exhaust pipe, and too lean a mixture to ignite (thankfully). If it were 270 camshaft degrees and opening on power stroke, then it's sucking air (without fuel) through exhaust valves and compressing it on the exhaust stroke (since valves aren't open), which blows back through the intake valves when they open at the beginning of the intake stroke -- not allowing mixture in through the intake valves until the bottom of the intake stroke, if at all. But heed ionbeam's counsel first -- the man learned this the hard way.

Of course, it'll turn out that I'm wrong, but I'm sure I'll learn something. Where the hell is jestal -- at work??

 

[ionbeam]

:fie: :dribble:

Stop right here, don't go any further!!! What you really, really need to do is a cylinder leak down test. This will tell you if you have a valve timing issue. Take it from this sorry sucker that you don't want to turn the engine over any more until you sort this out. You won't have to pull the cylinder cover off to do this, but you will have to have access to the crank timing marks. First though, does your engine turn over faster than normal? If yes, then read on. If no, you may want to skip what follows, it *may* not apply.

Pull all 4 plugs out. Manually turn the engine over until a cylinder is on the compression stroke, at Top Dead Center (TDC). Screw the spark plug hose of the leak down checker into the spark plug hole. Not required but it doesn't hurt -- put the engine in first gear, activate the rear brake. Apply 100 psi to the leak down gauge set, using the input pressure gauge to measure the 100 psi. Read the leak-down gauge, 95 psi = 5% leak-down. 90 psi = 10% leak-down, anything less than 87% and you are phucked. You should repeat this for all 4 cylinders. However, you are not verifying the health of your engine, you are looking for gross failure, so if you find even one cylinder that is less than 87% there is no point in going on. This is what a leak-down gauge set looks like:

I REALLY hope that this is for nothing but... The cam chain opens and closes the valves in a synchronous motion so that the exhaust valves close before the piston reaches TDC on exhaust stroke. The valves must stay closed during the compression and power stroke. If the exhaust valves were to skip timing in one direction the valves can be open/in the combustion chamber when the piston comes up, or if off in the other direction may try to open when the piston is at TDC. I'll be posting pictures of the catastrophically damaged parts that result from this.

I hate to be an alarmist in this, there is probably a simple root cause, but if there is any chance that your exhaust cam is out of time, you don't really want turn the engine over any more. The leak-down test is the best method to diagnose this potential situation. You could pull the cam cover. You could try a compression check which you may have the tools for but it entails turning the engine over.

Let me know how you are making out! I see my PM box is full again; I will make some room tonight. Send me a PM and I will send you my personal email address.

I hope you have been paying into the good karma bank!!!

 

[PapaUtah]

180 cam degrees...360 crank degrees...either way it ain't right. If they haven't already touched the valves are missing each other by fractions of a millimeter....

 

[Geezer]

MNFJR05 and EXSKIBUM have the right answer. I pulled the valve cover off after work today and the exhaust cam was 180 out. The lobes aligned with the intake lobes.

I was careless when I put it back together and just aligned the timing marks. Well, guess what, there are two timing marks on each cam, one on top and one on bottom. So, the answer is to make sure the intake cam lobes and exhaust cam lobes on the number 1 cylinder are facing away from each other. I never had the chain off the intake cam so I know that one is right.

I don't think I have any valve damage because the valves were opening during the time when the intake valves should open anyway, so the piston had to be clear. There was no noise when hand cracking. I don't know if it's possible for the exhaust and intake valves to interfere with each other on this head.

I'll check the timing one more time tomorrow and button it back up.

It's amazing how much easier the whole valve adjustment procedure is the second time you do it.

Next time I adjust the valves I'm going to put a small tie wrap through one of the holes in the cam gear and around the chain for each cam so the chain can't come off the gear as I lift the cam.

 

[exskibum]

MNFJR05 and EXSKIBUM have the right answer. I pulled the valve cover off after work today and the exhaust cam was 180 out. The lobes aligned with the intake lobes.

Damn, so you did have all 4 valves open on intake stroke! Now the exhaust can go back to blowing.

That's GREAT news! Get yourself down to the local store and buy some lottery tickets while that good karma is still favoring you!

And thanks for the cautionary tale of how easy it is to make that mistake on this engine. Haven't had occasion to do mine yet, so I appreciate the advance heads up about what it looks like inside.

 

[Geezer]

[SIZE=18pt]It runs[/SIZE] :yahoo:

I checked the cam timing one more time today, put the valve cover on and the minimum plumbing and other stuff necessary to give it a try. It runs. I let it warm up and did a TBS while I had the T bar off. No leaks and it sounds good. I'll put the rest back together later and take it for a spin tomorrow. Whew!

Hints and tips for a valve adjustment, in addition to the excellent write up on fjrinfo I would add the following:

1) remove the spark plugs before you start turning the engine.

2) you can turn the engine to check the valves without removing anything from the right side. Pu the bike on the center stand, get the transmission into high gear, and turn the back tire in the forward direction to turn the engine

3) If you have to adjust the valves, make sure you have the engine at TDC for the number 1 cylinder before you loosen the cam chain tensioner or any of the cam retainers. TDC is when the lobes on the intake and exhaust cams are approximately opposite each other. You can then see the timing marks on the gear end of the cams as they align with the arrows.

4) Take a picture of the cams, including the timing marks, and the timing marks on the end of the crankshaft so you have a good reference if you need it later

5) Use a small tie-wrap through one of the holes in the cam gear and around the chain and pull it tight so the chain can't come off the gear. Do this on both cams.

6) On the right side, inside the cover, there is a steel dowel that retains the cam chain guide. If that dowel stays with the cover when you remove it (like it did on mine) the guide can slip down when the chain is loosened. It will bind the cam chain.

7) The size markings on all of the shims I removed had worn off. You will need a micrometer or caliper to measure them so you can determine what size to replace them with

8) I used duct tape to hold the spark plug wires out of the way. I also used duct tape to hold the throttle cables after I rotated them back.

That's all I can think of right now. It is really not a bad job if you move very slowly and look everything over very well before each step. I did the job with the tank raised and held with a strap, but it would have been much easier with the tank completely off and out of the way.

 

[FJRMGM]

glad to hear you fixed the problem and it runs.

 

[Fred W]

Wowsers. You dodged a high caliber bullet there, Geezer. You must treat old ladies and animals very nicely to collect up such good juju.

The best thing that you did was to hand turn the engine through multiple crank rotations before you ever hit that starter button.

For anyone else considering doing this job, you really need to be meticulously careful when messing with valve timing or you can turn your beautifully running engine into a useless mooring weight. Before releasing chain tension tie-wrap the chain to the cam sprockets so you will not lose the cam to cam timing. Then double check the crank to cam alignment in case the chain skipped teeth down on the crank and you should be good to go.

 

[Malve]

"now sucking instead of blowing"

Boy this was a softball...where are all the wise *** remarks? Appears to be a defficiency. I'll try to make up for it with a couple:

Sounds like you've got a $10K *** toy

Can you make the same mistake on my wife?

 

[Fred W]

"now sucking instead of blowing"
Boy this was a softball...where are all the wise *** remarks? Appears to be a defficiency. I'll try to make up for it with a couple:

Sounds like you've got a $10K *** toy

Can you make the same mistake on my wife?

I think we're all worn out from the frivolousness yesterday... :blink:

 

[Constant Mesh]

When is the Plastigauge clearance measuring material used? In the service manual Plastigauge is referenced when installing the camshafts. Is this recommended only when installing new camshafts and caps? Not necessary when adjusting valve clearances on a 26K+ mile engine?

 

[Fred W]

When is the Plastigauge clearance measuring material used? In the service manual Plastigauge is referenced when installing the camshafts. Is this recommended only when installing new camshafts and caps? Not necessary when adjusting valve clearances on a 26K+ mile engine?

correct. It's used to measure the bearing clearances. You could check your plain bearing clearances with it at 26k miles, but what you gonna do if they're out?

 

[Geezer]

"now sucking instead of blowing"
Boy this was a softball...where are all the wise *** remarks? Appears to be a defficiency. I'll try to make up for it with a couple:

Sounds like you've got a $10K *** toy

Can you make the same mistake on my wife?

Yes, I did expect some humorous responses to that one. I was pretty sure I had put the cam in wrong but I wasn't in the mood to pull the valve cover off. Turns out that it's a lot easier the second time.

Anyway, as Fred said, my attempt at humor was lost in the April Fools shenanigans. <_<

 

[Constant Mesh]

Measure twice before you cut.

 

[Charlie Hoss]

Turns out that it's a lot easier the second time.

I bet the 3rd time would be REAL easy, even fun. How's about coming up for a day or two and help me do mine? I'll buy the Guinness! :drinks:

Glad to see you dodged the bullet and GOTRDUN (my license plate).

 

[feejer222]

AWWWWWW! I thought this was an April fools.

 

[Geezer]

Turns out that it's a lot easier the second time.

I bet the 3rd time would be REAL easy, even fun. How's about coming up for a day or two and help me do mine? I'll buy the Guinness! :drinks:

Glad to see you dodged the bullet and GOTRDUN (my license plate).

Sure. A ride up to Maine would be great fun. It will have to wait until May or June.