Camshaft Top End Rattle

[Guest]

You know Don my 450 used to make a noise similar somewhat to what I can hear in your video there, and it was just the noise the exhaust made at idle, that was it, rev it and gone. Drop the idle and gone.

I think it was because the baffles were rusting and the pipes were rusting.

I must say though that that was back in, well... late 90's when I discovered that and figured it out, so my memory is a little foggy and it's a little hard to tell from the video.

However, congrats again on getting it complete and running, it does sound good to my ears and is makin' me a little jealous and impatient for mine to be running again.

 

[Suzuki_Don]

Thanks Pete for the encoragement. I will persevere.

 

[salty_monk]

Nothing touching the frame is there? One of my bikes used to touch the coils to the tank underside unless I mounted the tank in a particular way...

 

[Nessism]

Sorry to hear the noise isn't gone Don. Good thing that bike isn't mine since it would have been over some cliff by now if it was.

Can think of only two things: the engagement of the clutch and crank gear is messed up somehow as evidenced with the contact pattern being offset, or that hole in the cylinder wall is causing the noise. How about selectively pulling off spark plug caps to deactivate each cylinder while taking note of any changes to the noise? Try to figure out if the noise is occurring with the same frequency as the crank, or if it's 1/2 or what? If the cylinder with the hole is causing the noise the engine should sound different with that spark plug pulled off I think.

Sorry I can't offer anything more specific.

Ed

 

[tkent02]

Does it sound the same with or without the clutch lever pulled in? How about with the clutch in idling in gear? Is this the same bottom end engine you had in the bike before the 650 mod? If so was it silent then? Have you listened with a stethoscope of some sort to determine better where the sound is coming from? One more thing I would try is to assemble the valve cover without the rubber half moons and chrome covers, see if pushing in the end of the cam shafts as it idles changes the noise at all. Push with a nylon tipped tool or something, not sure quite what.

 

[salty_monk]

Ride it until it goes bang.... I bet we'll find the problem at that stage

Very frustrating!

Good luck Don

 

[tkent02]

Ride it until it goes bang.... I bet we'll find the problem at that stage

That will be a long ride, methinks.

 

[Suzuki_Don]

Thanks guys. I will try those ideas as well as synching the carbs. Can I check the synch on the carbs without warming the motor just to get a rough idea how far out they are from each other. You see it's raing here and not expected to stop for a few days.

I have tried the stethescope ideas but cannot really localise the noise to any particular spot, it seems to be everywhere. Although I am not so sure it's coming from the top end now, it sounds more around the clutch housing area. But hard to tell.

 

[waterman]

You can certainly synch carbs without motor being hot. It may not be perfect, but I doubt it will be that far off.

Sorry to hear the problem hasn't been resolved. My 650 has tick at idle that I have almost given up caring about. Doesn't happen all the time nor does it sound quite as steady as yours.

I know you haven't driven it too much since the tear down, but did the air jets seem to help?

 

[Suzuki_Don]

You can certainly synch carbs without motor being hot. It may not be perfect, but I doubt it will be that far off.

Sorry to hear the problem hasn't been resolved. My 650 has tick at idle that I have almost given up caring about. Doesn't happen all the time nor does it sound quite as steady as yours.

I know you haven't driven it too much since the tear down, but did the air jets seem to help?

Hi Ed, initially on startup it was popping in the exhaust when I revved it in the shed, but i only ran it for two minutes. I took it out yesterday and when it was warmed up it was idling fine and there was no hesitation or lag between the different stages of throttle openings. Very happy with the power and will check the spark plugs after a longer run when they have had time to get a bit of colour.

 

[mlinder]

Any chance of recording the sound, Don?

 

[Suzuki_Don]

Any chance of recording the sound, Don?

I did Mark,on post #238. Let me know whay tou think.

 

[Suzuki_Don]

Carbtune Test

Carbtune Test

I just whacked my carbtune on and came up with these results.

Thoughts!!!!!!!!!!!!!

 

[tkent02]

Thanks guys. I will try those ideas as well as synching the carbs. Can I check the synch on the carbs without warming the motor just to get a rough idea how far out they are from each other.

You could do it after a good thrashing, check it hot. I wouldn't run the engine and take any time to get them perfect until it's well broken in, that window of opportunity thing. I'd just check it for a couple seconds and shut it off. If it's way out of synch, (which it shouldn't be with a good bench synch on a tight new engine) maybe give it a quick tweak but that's it. Synch doesn't matter much at wide open or closed throttle, which is the only thing you should be doing at first.

If it were my engine, I wouldn't even bother until the rings were well seated.

BBBWWWWAAAAAAHHHHHuuuunnBBBWWWAAAAA

 

[Nessism]

Window of opportunity baah. If the hone gets worn off what does it? Why the rings of course! How can you wear off the hone without correspondingly wearing the rings? Answer: you can't. Don't get me wrong, I'm in favor of using lots of throttle, I just think some people go to far in their paranoia.

So Don, how does the engine sound after fixing the sync?

 

[Suzuki_Don]

So Don, how does the engine sound after fixing the sync?

Ed I haven't done the synch yet, just put the gauges on to see how far off they were. Seems a fair bit to me, what do you think?

Ed as far as the wear pattern on the crankshaft web gear goes, how could that be off. The crank main bearing seat on dowels in the upper case so that positively locates the crankshaft longditudinally, Right. It can't move. So the other option is the clutch gear is not lined up, any ideas how that could happen. I put it back together the way it came apart. It drives the oil pump properly, there is no interference with clutch housing, etc.

I notice that the primary reduction ratio is 93/47 for 1977 and for 1978/79 is 87/44 so I wonder if someone previously mismatched a clutch with a different tooth combination. Probably would not fit. I don't know. What's going on.

Any suggestions as to why the primary gears are not running true to each other.

Had my rest back out to the bike now.

P.S. Is it OK when synching the carbs to loosen all three lock nuts on the adjusting screws at once and then muck around adjusting the three screws to get the adjustments correct. Or do you just loosen one at a time?

.

 

[Nessism]

Hi Don,

Adjust 2-3 first, then the outside carbs in no particular order. I always do the sync before riding the bike and yes, yours is WAY off. I'm fairly certain the engine will be much quieter with the sync adjusted correctly. As far as the crank gears go, no clue. Doesn't seem right but might be perfectly normal. I agree with you in that I don't understand how it could be off.

 

[Guest]

That sync is way off Don. Was that with a warm engine and no choke?

I wouldn't want to run another 900 kms with sync like that.

You could pull them roughly into line quite quickly after warming up the bike with a 5 minute ride.

 

[tkent02]

Any suggestions as to why the primary gears are not running true to each other.

Just looked at my 550 engine which is sitting there with the clutch cover off. The clutch is not installed, but the wear on the crank gear teeth looks to be misaligned identically to yours.

 

[Suzuki_Don]

Just looked at my 550 engine which is sitting there with the clutch cover off. The clutch is not installed, but the wear on the crank gear teeth looks to be misaligned identically to yours.

Thanks Tom, that puts my mind at rest.