Started Bike w/o Cam Chain Tensioner Now It Won't Start Again

[Imgnr]

So...the saga continues. I took the left head off to put a new one on as the PO had crashed it cracked the part where the cover bolts into.

 

Anyhow, put everything back together, started it, lost about a quart of oil through the cam chain tensioner hole because I forgot to put it back on (waiting for new one to arrive). When it arrived, I put it on and now the bike refuses to start.

 

Thoughts?

[dirtrider]

Afternoon Imgnr

 

Does it crank but not fire or won't it even crank over?

 

Side stand isn't down with trans in gear is it?--Kill switch turned ON?

Edited May 31, 2017 by dirtrider

[Imgnr]

Dirtrider - seems like you answer everyone's questions! Thanks for taking the time to help out.

 

Keeps cranking but does not start. Doesn't attempt to start.

 

Side stand is up, center stand is down. Kill switch is not on.

 

Not sure about transmission gear. Seems like it's not shifting through all the gears and neutral light does not come on. Hoping to take it out for a first ride to check all the gears.

 

Clutch is in.

 

Is there a kill switch on the center stand too?

[dirtrider]

 

 

Is there a kill switch on the center stand too?

 

Afternoon Imgnr

 

No switch on center stand.

[dirtrider]

Afternoon Imgnr

 

Can you hear the fuel pump run for a couple of seconds at key-

on?

 

If it cranks over then you are probably missing spark or fuel.

 

Pull a plug wire off of one of the spark plugs, then hook it to a (known good) spark plug, now lay that spark plug on the cylinder cover or engine head & crank engine (does it have spark?)

 

If you have spark then disconnect the fuel return hose coupling & hold the inner check valve open. Point fuel coupling into a container. Now turn key on (do you have fuel flow for about 2 seconds?)

[Imgnr]

Dirtrider - thanks - will try but since it started just a few days ago even with no compression in one cylinder, I'm trying to trace back what I might have done differently.

 

If the bike is in gear with the clutch pulled in and the center stand down, is there a kill switch that would be activated?

[dirtrider]

 

If the bike is in gear with the clutch pulled in and the center stand down, is there a kill switch that would be activated?

 

Afternoon Imgnr

 

No, there is no safety switch on the center stand.

 

Have you tried starting it with the throttle held at 1/4 throttle?

Edited May 31, 2017 by dirtrider

[Imgnr]

Will try it w/ the throttle. Also, the oil spurted out and got on everything on the left side. The electrical connections are supposed to be watertight and I don't think oil should impact conductivity but I'll also try cleaning the connections.

[dirtrider]

Will try it w/ the throttle. Also, the oil spurted out and got on everything on the left side. The electrical connections are supposed to be watertight and I don't think oil should impact conductivity but I'll also try cleaning the connections.

 

Afternoon Imgnr

 

I suppose your L/H side cam chain could have jumped timing without any pressure on the guide rail.

 

Do you have compression on the L/H side?

 

You can always check the cam sprocket arrows to verify the L/H cam is still in time.

 

 

 

[Michaelr11]

Dirtrider - seems like you answer everyone's questions! Thanks for taking the time to help out.

 

Keeps cranking but does not start. Doesn't attempt to start.

 

Side stand is up, center stand is down. Kill switch is not on.

 

Not sure about transmission gear. Seems like it's not shifting through all the gears and neutral light does not come on. Hoping to take it out for a first ride to check all the gears.

 

Clutch is in.

 

Is there a kill switch on the center stand too?

 

"Neutral light does not come on." That will do it! Try pulling the clutch lever in and try to start it. If Neutral light isn't on, the bike thinks you aren't in neutral even if the gear indicator shows 0.

[Imgnr]

Turns out that I had the centerstand down but didnt put up the kickstand. This bikes much more complicated than my 72 CB500F.

 

So it fired up but only on one cylinder.

 

Has spark (pulled plug wire and tested it against one of the fins)

Has fuel (pulled the injector head and cranked the engine and could feel puffs of gas).

Not sure about compression. My tester doesnt have a long metal connector that can reach all the way into the plug hole so i couldnt really get a tight fit. Complression read low at 60 but i think it might be the poor seal.

 

- what are some common mistakes people make when installing a new head that could prevent the cylinder from running or low compression?

- im pretty sure ill be taking the head out and redoing it again.

 

Thank you

[dirtrider]

Turns out that I had the centerstand down but didnt put up the kickstand. This bikes much more complicated than my 72 CB500F.

 

So it fired up but only on one cylinder.

 

Has spark (pulled plug wire and tested it against one of the fins)

Has fuel (pulled the injector head and cranked the engine and could feel puffs of gas).

Not sure about compression. My tester doesnt have a long metal connector that can reach all the way into the plug hole so i couldnt really get a tight fit. Complression read low at 60 but i think it might be the poor seal.

 

- what are some common mistakes people make when installing a new head that could prevent the cylinder from running or low compression?

- im pretty sure ill be taking the head out and redoing it again.

 

 

Morning Imgnr

 

That is what I like to see, something simple on the starting issue.

 

On mistakes when installing the cylinder head-- usually cracking a cam chain guide or not getting the cam timed correctly.

 

Can you tell what side cylinder isn't firing? (that will be the side with the coldest exhaust pipe) --If it's the right side then make darn sure that the throttle cable is FULLY & FIRMLY seated in the throttle body cable adjuster ferrule. If the cable is sitting on the top edge of the ferrule then that side cylinder will be dead at idle.

 

If your problem isn't the R/H throttle cable at the TB ferrule then you will probably need to re-check the cam timing & do a well sealed compression test. (the cam can be re-timed without removing the cyl head)

 

 

Edited June 1, 2017 by dirtrider

[AndyS]

...So it fired up but only on one cylinder.

Which cylinder is firing?

[Imgnr]

The throttle cables are seated properly.

The CAM chain is in the proper position (arrows are horizontal at TDC).

 

The one not firing is the left one; the new one I put in that came with the bike. The PO ordered it on E-Bay (no idea how long ago). I did not check the head I put on - could the valves be stuck? The plug I pulled out of it was very rusty.

 

I'll do a compression test again. If it's low, guess I need to pull the cylinder, rehone, and change the rings? Doesn't seem like that much more work once the head is off. Thoughts?

 

Thank you for the sage advice.

Edited June 1, 2017 by Imgnr

[dirtrider]

The throttle cables are seated properly.

The CAM chain is in the proper position (arrows are horizontal at TDC).

 

The one not firing is the left one; the new one I put in that came with the bike. The PO ordered it on E-Bay (no idea how long ago). I did not check the head I put on - could the valves be stuck? The plug I pulled out of it was very rusty.

 

I'll do a compression test again. If it's low, guess I need to pull the cylinder, rehone, and change the rings? Doesn't seem like that much more work once the head is off. Thoughts?

 

Thank you for the sage advice.

 

Afternoon Imgnr

 

But is the L/H arrow horizontal on the correct engine stroke?

 

With both valve covers removed, both pistons at top of stroke, & arrows pointing out are one side valves all loose & the other side all tight with a couple of depressed valves? If not then you might have that L/H cam 360° out of time.

 

The BMW boxer is a 360° engine so one side fires then 360° later the other side fires. (so if ALL valves are loose or all valves are tight with pistons at TDC then ones side is out of time)

 

Otherwise definitely do a compression test as well as a leak down test (at least pressurize the L/H side cylinder with compressed air & all valves closed & see where the air comes out)-- will tell you if you have leaking valves or leaking rings)

[Imgnr]

So, I took the head off to see what's going on. The bottom exhaust valve is actually impacting the piston. I adjusted the valves and the timing seemed good. The valves are all closed and the piston is at the top of the stroke.

 

Do you think the valve's bent?

 

I'm sure there's something very simple that I'm not doing.

 

Thank you!

 

 

Edited June 3, 2017 by Imgnr

[dirtrider]

So, I took the head off to see what's going on. The bottom exhaust valve is actually impacting the piston. I adjusted the valves and the timing seemed good. The valves are all closed and the piston is at the top of the stroke.

 

Do you think the valve's bent?

 

I'm sure there's something very simple that I'm not doing.

 

Thank you!

 

Afternoon Imgnr

 

Well you either had the cam timing out of time or that valve is/was sticking

in it's valve guide.

 

In any case if it was me I would suspect that valve is bent (or good

possibility anyhow)

 

You might oil the valve stems inside the valve springs, then use a

rawhide mallet to pound on the valve stems (where the rocker arms hit)

to make sure that all the valves will move freely in the guides.

 

Then, one by one put some fluid into the each exhaust port & intake port

(enough to completely fill the area around the valve heads)

 

Now look for signs of fluid seepage past the valve seats.

 

That doesn't totally guarantee that a valve isn't bent but will

definitely show one that is bent enough to leak.

[Imgnr]

Success! Leaned on the rocker arm / valve stems with a block of wood on the valve ends so they wont get damaged. They opened and closed fine. Put in some lubricant in case there is crud between the valves and the head. Reassembled, double checking all torque values. The slot where the cam bolt screws into was not aligned. I think this may be the culprit. I made sure that it was aligned with the cam sprocket.

 

Adjusted the valves again. Buttoned everything up, crossed my fingers, pushed the button and both cylinders roared to life!

 

Now on to making sure everything works properly.

 

Thank you again everyone with a special shout out to dirtrider.