Guzziboys gsx400F of death

[guzziboy]

Hey guys thanks for your suggestions I can't tell you how much it's appreciated!!

So I did have a small win with the timing mark and took mr Agemax's advice and took another look at my back plate and found this tiny mark under the screw



So it got me thinking it must be there for a reason where I got the torch and laid in the dirt to find this little bad boy



God dammnit!!!!!

So that makes both my cams out of whack by my measurements .. Trying to get some info out of the old owner to see wtf!

[hjfisk]

Hey guys thanks for your suggestions I can't tell you how much it's appreciated!!

So I did have a small win with the timing mark and took mr Agemax's advice and took another look at my back plate and found this tiny mark under the screw



So it got me thinking it must be there for a reason where I got the torch and laid in the dirt to find this little bad boy



God dammnit!!!!!

So that makes both my cams out of whack by my measurements .. Trying to get some info out of the old owner to see wtf!

Those marks you have pointed out are for ignition timing only, not your cam timing. You should have a some marks on your ignition advancer plate[ under the pick-up pulse plate ] that have a T 1-4 and a T 2-3those are you cam timing marks. It probably is not exactlly the same but I bet it is close to what an 1100 16 valve set up is. Look in the 1100 GSX manual 80-83 for . The mark you have circled next to the mounting post is probably correct but not the other. keep looking.

[Agemax]

the circled mark will be your TDC mark. put the advancer back on and the back plate.the small mark on the back plate will line up with the circled mark.
as said, rotate the engine until T 1-4 on the advance unit lines up withe the marks.
that is your base mark for your cam timing

[guzziboy]

Okay I can't work it out the previous owner is saying he had it going three years ago ?????! Dubious to change things now WTF !

[pete]

Ignore what the PO says.

Go by the manual and start from scratch, checking everything off one at a time.

You can pop the spark plugs out and watch the cylinders while rotating by hand to ensure they are at TDC when the timing mark says they're at TDC.

On my 450 I can see the valves opening and closing so hopefully you'll be able to see if they're going to hit the piston due to bad cam timing.

[cowboyup3371]

Pete's right, POs lie ALL THE TIME. Really pay attention and do the maintenance yourself properly from step 1.

[Mekanix]

I can guarantee that you are off with the cam timing!

Maybe both cam's.

Here is what I would do.

Step 1

Get piston # 1 and 4 ( all the way on the left and right) to TDC by lining up the mark on your engine casing to the line beside the T on the ignition advancer.

There is a T for 1 and 4 and a T for 2-3 . Look at the plate and you should see something like T| F| with 1-4 under it. That's what your going to set it on first.


Step 2

Remove the timing chain tensioner.

Step 3

Remove the camshaft caps.

BE careful here, Try and turn the cam's so that they are the most relaxed. As in: not pressing directly down anywhere.

If you can't get it at a good spot that's ok.
The thing you have to be careful with is removing the cam caps equally.

If one side comes up more than the others then the there is a good chance you can strip threads out of the head.

So just do a few turns at a time trying to keep everything equal as it comes up and the same thing when they go back down.


Step 4

Reinstall the exhaust camshaft first so that the # 1 is pointing straight forward, the # 2 is pointing straight up and the notch in the end is pointing backwards.

Make sure your pulling the chain tight in the front and check the timing marks on the crank to see if it moved while you were keeping tension on the chain and tightening the cam back down.
I would just stick a wrench on the crank and hold it or tape it to the engine to prevent it from moving.


Tighten it down and see if it lines up.

You might have to do that 2 or 3 times because the cam might rotate as you tighten the caps down.
In that case just advance or retard the cam a bit on the chain and tighten it down again until its right.

Step 5

Same thing for the intake cam, only this time its easier because all you have to do is count 23 pins between the #2 on the exhaust cam and the #3 on the intake cam. That is 23 pins including the first and last pin's.

The two notches should be pointing towards eatchother now.

Step 6

Reinstall the timing chain tensioner.

You have to rotate the knob and push it in as you rotate and hold it rotated as you put the bolts back in.
Once you let it go, it will stop the plunger from pushing back out and automatically start taking up the slack in the chain.

There might be some slack somewhere in the chain, Hopefully its all in the back where it should be.

Step 7

Rotate the engine slowly, If your 1 tooth off it either direction you will feel a stop, and even then you can push through that point if you try, So don't push it.

If you make it around 1/2 turn look at the notches in the cam's. The EX cam should be pointing straight up and the Intake straight down.

Try another 1/2 turn and check the timing mark when you come back around to it.

Line it up and make sure the notches are pointing away from eatchother and parallel with the head.



After that just lube the rockers and cam's and try rotating it around a few times to make sure everything is ok.


If the cam's are not perfectly aligned and your a tooth off that could be that there was some slack in the front and you have to start over again.

[guzziboy]

outstanding explanation thanks dude
going to attack it this weekend!

[Mekanix]

Something I just thought of.

On each cylinder when ever you have the lobe pointing straight up, check the clearance between the valve stem and the pin on the rocker.

Should be 0.03-0.08mm I think, the numbers are in the manual though.

If you get any numbers that are larger than that by quite a bit you might have bent valves.

That's just one way to tell.

But with the way it is, I think The intake valve is opening when the piston is about to move back up and then its rushing away fast enough so that the piston doesn't hit it.

http://www.youtube.com/watch?feature=player_embedded&v=k91yo3unKzY

Take a look at that and try to imagine the intake being 1/4 turn retarded.


Here's the parts list for your bike

Or

http://www.cmsnl.com/suzuki-gsx400-1981-fx_model13621/partslist/?model_q=gsx400

[tatu]

+1 on what Mekanix is saying, What you are looking to do is on #1 you want to have the compression stroke where the marks will all line up if everything is ok the way to confirm this is on the next full rotation of the crank, so #1 is back up to TDC (top dead center) is that the cams should be "on the rock" ie the exhaust is just fininshing its closing cycle and the inletis starting its opening.
If you go through this the timing marks will align and become clearer.
Just to be clear on what has been said, always rotate the engine slowly through the whole process, you will find TDC by taking out the #1 plug and looking or ursing something to feel it, like a screwdriver.Using this method you can manage the job without timing marks entirely, but they are always there. It is a good way to find the marks when on some engines they are hard to find.

[pete]

Awesome Mekanix! I just don't have the head to explain that stuff... I'd have to sit there reading the manual for half an hour then very carefully follow it step by step...

[cowboyup3371]

Step 1

Get piston # 1 ( all the way on the right) to TDC by lining up the mark on your engine casing to the line beside the T on the ignition advancer.

Great information but just one correction here to the bolded words. The number 1 cylinder is under the clutch handle side of the bike which, if you are sitting on the bike, is under your left hand.

[Mekanix]

Your right, Edited.

[guzziboy]

Your right, Edited.

did i mention you guys are awesome!

[guzziboy]

So I pulled the thing apart this arvo and lined my cams up as per the manual it felt a bit weird when I had it back together thou ... It gets kind of tight when you turn it by hand.. But tighter and a harder sound than the normal compression sound ?? Gonna adjust all the valves tomorrow and see how it feels
Something weird going on here