help needed--camshaft problem again- COMPRESSION RESULTS

[Anonymous]

My GS400 was able to run with the tensioner off (it was on the bike but I didn't release it...) and all that happened was the exhaust cam jumped a tooth. No damage whatsoever. I have heard people being 2 teeth off before and not finding it until the next time they work on the valve clearances.

Please stop chaning the thread title and origional post. Having the full timeline of what you are doing is helpful.

Steve

[Anonymous]

just got work, and am about to get it all taken care of.


the question I have now, is:


Did I screw up (possibly bend a valve stem) by trying to bump start it? it never started up, even when trying to bump start, because the timing was slightly off, so I wonder if I bent a valve stem or not.

heres hoping to not

Run a compression test.

[Poot]

well, im midway through things now.....got the caps off, and everything timed right at TDC-1.4. im going to put on the caps, and see if the timing is the same, although it should be this time, because all of the lobes are in such a way that they dont push the camshaft up. this means that the sprockets aren't going to rotate once I tighten down on them, like they did last time.

i'm making sure I take the time to do things right.....like I should have done from the get-go....unrushed (off work early, and tommorows my day off)

good news , is that I dont think I bent a valve. The crank turns freely, and im guessing that if a valve was bent, then it wouldnt be like this.

Ill post an update in a little bit

[-o< 8-[

[Poot]

alrighty,


so I set the timing, and got the caps and idler assembly back in, and its still right on TDC1.4. and in time with the sprockets.

just gonna pop in my tensioner, carbs, and airbox before I start her up!


[-o< [-o< [-o< [-o< [-o< [-o< [-o<

[Anonymous]

cams

Bad news poot it means nothing that the motor turns thru now, there still could be valve damage( I hope not) you wont know till you run it and then do a compression test, I wish you well in this one, let us know

[Anonymous]

It takes a real hand-hand to bend valves by turning it over manually. Always use a light touch when cycling the engine to check for parts bumping into teach other. There is no need to force anything.

[Poot]

well, still no start tonight.... it seemed to trying to start up on 2 maybe 3 cylinders,, or just really rought b/c the carbs arent synched. I might also check the floats in my carbs to see if they're stuck, b/c I dont think fuel is getting to the engine (or not enough to run) b/c theres not much gas running from the tank into the carbs, but the fuel lines pretty much full, so I dont think the fuel is going anywhere.

i'm prayin that its only a problem with air intake/fuel supply, or timing, rather than something serious.

took my petcock off and cleaned it this winter. .. . the diaphragm still seemed to be in pretty good shape, and things were clean for the most part. one thing though, on my petcock, the allen-slot to adjust the setting (prime, run) just keeps turning in any direction.

I'm thinking this might cut off my fuel supply and be the reason my bikes not starting after this winter?

In that case, would the whole piece need to be replaced, or just the very bottom end of the petcock?
either way, im checking the timing and carbs out, since those are my two main suspects.(besides my ham-hand)

poot

[Poot]

well, it didn't start up, and I've gone back to check the timing. the timing is right on, but now I notice somthing else when double checking clearances.


the shim-bucket on the 4th cylinder (exhaust valve) is up way too high, and I am unable to rotate it around to be able to pop the shim out.
I think I might have screwed up the valve by trying to bump start with the timing set wrong. The valve itself, still moves up and down properly, but its not right for the bucket (and shim) to be up so high, b/c it touches the camlobe way too much.


does anyone have any ideas as to the specific cause/solution for this? I know it might come down to taking the head off to check the valve itself,...

[Anonymous]

well, it didn't start up, and I've gone back to check the timing. the timing is right on, but now I notice somthing else when double checking clearances.


the shim-bucket on the 4th cylinder (exhaust valve) is up way too high, and I am unable to rotate it around to be able to pop the shim out.
I think I might have screwed up the valve by trying to bump start with the timing set wrong. The valve itself, still moves up and down properly, but its not right for the bucket (and shim) to be up so high, b/c it touches the camlobe way too much.


does anyone have any ideas as to the specific cause/solution for this? I know it might come down to taking the head off to check the valve itself,...

I thought you said you only turned the motor over manually? If you used the starter then all bets are off on the bent valve.

It sounds like the valve is sitting too high. If it was too low, then I would think bent valve. If it's too high and the cam lobe is touching on the cam circle base, then the valve isn't closing all the way.

I'd runa compression test first - because it's easy and tell a lot. If that cylinder is leaking I'd try to adjust the valve to correct it. If you cannot adjust the valve, then it's probably bent.

[wrench]

Swanny's right Poot, you need to do a compression test, if you dont have a compression gauge i have one your welcome to borrow.

[Anonymous]

cam

The only way that the valve went to tight if it wasnt before is if the stem stretched very unlikely or the shim is not seated in the bucket right, witch is more than likely, or you miss calculated the adjustment

[Anonymous]

Re: cam

The only way that the valve went to tight if it wasnt before is if the stem stretched very unlikely or the shim is not seated in the bucket right, witch is more than likely, or you miss calculated the adjustment

This is true.

Poot, you seem to be running into a series of issues, each one somehow related to the previous. Pardon me, but this looks like a classic example of digging in to a job without being fully prepared. The number one thing you have to do prior to taking something apart is to understand the procedure for making it whole once again.

I'm not being overly critical either. It is my number one rule - that and having enough tools and beer on hand for the job. 8)

[Poot]

Re: cam

The only way that the valve went to tight if it wasnt before is if the stem stretched very unlikely or the shim is not seated in the bucket right, witch is more than likely, or you miss calculated the adjustment

DING DING DING!!! and we have a winner! after sitting down infront of my bike, and took a look at the shim+bucket, and after taking out my tappet depressor tool, it turned a tad somehow, and seemed to seat a lot better. then i could turn it with my fingers, like normally, and i popped the old shim out (2.60mm) and put in a 2.55 mm, and now it seems to be doing great with clearance >.038mm

So , where I stand now, is that my timing is bang on, and my clearances are good, my tensioner set properly, and my air-adjustment screws on carbs all set at about 1.6 turns out, and a fully charged battery, with new spark plugs.

im going to do the ghetto compression test for now , by placing my finger on top of the spark plug hole, until I get a compression gauge, which might be later on today.

___________--
i here ya swanny..... my problem started as not undoing the locknut on the tensioner, which gave me the rattling sound, which made me want to check my timing, and then to correct it (and screw it up more, and then fix it), and so on and so forth.

i seem to be wrapping my head around the problem better , and better, and keep praying that making my bike my gunea pig wont be fatal for it.

the learning curve has been reeeaaal steep, but i'll keep persisting. my biggest (and hardest) lesson was : DONT RUSH THINGS!!!

poot

[Poot]

hey guys,


well, i went out and bought a compression gauge, and did the test (all plugs out, full throttle, and let it crank evenly for each cylinder

this readings are as accurate as I could get....the gauge is not digital.
I performed this test with the engine cold

Cylinders before adding oil------------>AFTER
-----------

1: 130 psi went up
2: 120 psi went up more
3: 133 psi went up
4: 150 psi went very slightly up




so, I guess the new is that I dont think I have toasted my motor, but I know now that my rings arent quite up to par.

Also, I actually got it started and running (had to keep the throttle on a little). without much trouble , and it starts right away.

All I have left to do, is get a 2.60 shim from suzuki, to replace the 2.55 on the intake valve on #3. after like 30 seconds of running, I felt all of the headers, and nearly blistered my fingers on #3, but I know that the problem is the clearance.

i'm almost there!!! 8-[


poot

[RacingJake]

Do a 2nd compression check after you get yor shims right and the ignition timing set. Then get it good and hot and see what the readings are.