"1982 GS 550 Cam Timing "No Start"

[curtie94]

Ok so I just got the engine back together, did a base and head gasket. I did the cam timing, but it seems like I'm half a tooth off no matter what I do. Is that even possible on these? I have the exhaust and intake cams 20 links apart like the manual shows, I even set the exhaust cam with the "1" even with the case. But when I bolt in the cams the crank moves and I'm out by half a tooth, I tried moving one full tooth but then I'm out the other way.

So after my cams are bolted in my "1" arrow is at a slight angle up and the 2 is not straight up and down. Is this common? What am I doing wrong?

I eve tried holding the crank steady with a wrench, but the cam timing was still not correct.


SO I thought maybe that is how it was supposed to be, it turns over without hitting anything, but it wouldn't start, it would catch for a second then just kept turning over.

Thanks in advance!

 

[Steve]

Your symptoms almost sound like you are not using the correct mark on the crank. :-k

Make sure you are using the |T mark, not the |F mark.

The 1 will not always line up perfectly with the edge of the head, and it doesn't matter whether the 2 is pointing up or not. It is only the starting point for your cam link counting.

Counting links on the cam chain is another point that is easily missed. The pin that is directly over the #2 is not ZERO, with the next one being ONE, the pin over the #2 mark is ONE. Easily miscounted, so be careful and re-count SEVERAL times.

.

 

[curtie94]

I was using the T, and I was also starting to count at the pin above the 2, so maybe its something else.

I did also try putting a rag in the air box to give i more resistance in case the lid wasn't sealing but still nothing.

What else could I try if timing is not the issue.

The arrow for "1" is at just a slight angle up, but it is pointing to the case like it should.

I did check my spark and the spark seems weak , red to purple blue. I am using a dyna s. Im getting about 11V at the coils.

I did set valve lash.



I have already done intake boot o-rings, weather striping on the air box lid. cleaned carbs, I had it running before I did the head gasket and base gasket, compression is good. before when the head gasket was leaking I actually had to stuff a t shirt in the air box since the lid wasn't sealing, but I took it around the block.

What else can I try?

 

[Steve]

What else can I try?

For one thing, get that shirt out of the airbox.

.

 

[tom203]

".....but it wouldn't start, it would catch for a second then just kept turning over."

Is your "choke" system working at carbs? After some start attempts, any sign of fuel on plugs?

 

[curtie94]

The choke system did work, before I pulled the head.

One thing that I noticed is the choke closes by its self, when I open the choke of I don't hold our with my thumb it closes.

As for fuel on the plugs the porcelain stays white but the threads and ground now have soot.

 

[Nessism]

As the cam chain elongates with use the -1 mark on the exhaust cam will be slightly above the cam cover surface. Don't worry about it and also and don't worry about the position of the 2 mark, just make sure you have the cams separated by the correct number of cam chain pins. One other thing to look at is the notches in the cams; they should be directly facing each other and parallel with the cam cover surface.

Just to be safe please check the Newbie Mistakes thread linked in my signature and see if anything applies. In particular you need the airbox installed, air filter installed, and the airbox lid sealed and installed otherwise the carb mixture will be wrong and the bike won't run properly.

Good luck

 

[curtie94]

You say the notches on the cam, on mine they are facing away from each other, how do I fix that?

 

[Nessism]

You say the notches on the cam, on mine they are facing away from each other, how do I fix that?

Cam timing may be 180* out of phase.

You might want to rotate the engine 360* and realign the 1-4 T mark, then verify cam timing again. Pull out the #1 spark plug and make sure it's at TDC. It's easy to make a mistake on this (don't ask me how I know).

 

[curtie94]

Could the cam sprockets be on backwards? I did take them off but I put them on so that the wear marks where covered.

 

[curtie94]

I swapped the cam sprockets around and got everything in time. Same thing, it catches for a second then nothing. Plugs are wet so I put a new set of plugs and still nothing.

 

[tom203]

I swapped the cam sprockets around and got everything in time. Same thing, it catches for a second then nothing. Plugs are wet so I put a new set of plugs and still nothing.

Just the sprockets? You should have heeded nessism's suggestion on notches, see pic -

 

[curtie94]

I just turned the sprockets on the cam then bolted them back. On the exhaust sprocket the lobe closest to #4 cylinder is pointing to the right and the intake is pointing to the left.

On my cams the notches are at the end of the cam closest to #4 cylinder.

My 1 and 4 cylinders are at tdc.

 

[curtie94]

Timing is correct, marks all line up.

But still the bike won't start, put my hand over the intake inside the air box while turning the bike over and I felt very little suction, should there be more? Would a air leak around the air box cause a no start?

I can smell gas when I try to start it but the plugs seem to be bone dry.


Juts to sure the cylinders are numbered left to right when sitting on the bike correct? so it goes 1,2,3,4 not 4,3,2,1?



On my cams the notches are facing each other.


I even tried spraying starting fluid directly in the cylinders and it wouldn't start.

 

[Nessism]

Something funny going on. Maybe try pulling a spark plug and then using your thumb over the hole and cranking the engine to make sure you have compression.

 

[curtie94]

Funny you say that. I just checked compression using my thumb and its good.

I just pulled my carbs again, I'll go through them one more time, make sure the choke passages are clean.

With the carbs out should I be able to stay starting fluid directly into the intake and get it to start or not?

When I pulled my carbs one of the throttle slides was stuck wide open. Could that have been a factor?

 

[tom203]

" I just turned the sprockets on the cam then bolted them back. "

Huh? You mean as in remove the sprocket bolts and rotate sprocket 180 degrees and rebolt?? I hope that I'm misunderstanding you!

 

[curtie94]

That's what I meant.

I took the sprockets off before and want sure what the correct way to bolt them on was.

 

[curtie94]

I just checked the manual and I have the sprockets on correctly now. the notches face eachother. Could I be a tooth off on the crank? I only ask because everything is timed correctly until I install the chain tensioner and then the crank moves a little and im not 100% perfect like I was before. It seems like the crank moves but the cams dont.

If I rotate the crank so that the notches are exactly pointing each other, then my cam timing mark is flush with the case, BUT my crank timing mark is halfway between the T and the F on the advancer.

 

[curtie94]

Ok how about this.

If my cam timing is off by lets say a tooth, would the bike still run?

Like I said it turns over fine and every once in awhile it pops like it is trying to start buts thats it. Could I put rags over the carb intakes just to see if it is a air box leak?