Author Topic: After cam swap, won't start | Block off pics (Read 20728 times)

LoVel · « **Reply #50 on:** October 05, 2012, 10:38:49 am »

Just had my 500 too rich and it was blowing white smoke, unburnt fuel, could see it and smell it. Leaned it out a wee bit and fuel spraying out the tail and the white smoke are gone.

MCRider · « **Reply #51 on:** October 05, 2012, 10:46:19 am »

Quote from: LoVel on October 05, 2012, 10:38:49 am

Just had my 500 too rich and it was blowing white smoke, unburnt fuel, could see it and smell it. Leaned it out a wee bit and fuel spraying out the tail and the white smoke are gone.

Thanks for that. Such a thing is news to me but gives me hope some tuning on my project may limit the smoke.

stereosilence · « **Reply #52 on:** October 05, 2012, 11:35:48 am »

I got the head cover back off. The previous poster was correct. Post cam swap, I only ran it maybe 5 seconds. Anyway, I tried to show in the video that the notch is lined up with TF1-4 and that the cam is oriented correctly.

The sound is coming from the middle of the engine down where the cam chain goes. Did I just turn a cam swap into an engine rebuild?

Engine noise sans head cover

750resurrection · « **Reply #53 on:** October 05, 2012, 12:01:46 pm »

Good bike work (you're much faster than I) , great camera and sound.

It's not up top? $:-\$

stereosilence · « **Reply #54 on:** October 05, 2012, 12:03:54 pm »

I forgot to mention that I loosened the cam chain adjuster nut too. I guess I'm going to take the cam off and see what I can find out.

stereosilence · « **Reply #55 on:** October 05, 2012, 12:46:56 pm »

Ok guys. I have no smoke, don't jack my thread here.

I took the cam sprocket off and turned the crank and still made the sound. Therefore, it isn't anything having to do with the actual cam.

I took out all the plugs, and it would barely make the sound and would spin quite easily. When I put plug #2 (second from right) in, the sound grew louder and it was much more difficult to turn the crank. Then I put in another plug (now #1 and #2) and it was pretty much back to where I was.

What are my next steps?

Engine noise, no plugs
engine noise, with plug #2
Engine noise, plugs #1 & #2

MCRider · « **Reply #56 on:** October 05, 2012, 12:55:13 pm »

Man o Man.

Logic would dictate we go back to when it was running good, list all the changes made, then eliminate or study them one by one to find the spoiler.

If you didn't have the cylinders off (I think that's right?) i see no reason to suspect pistons/rings, etc.

Knowing nothing about it, but always in suspician of the 500/550 cam chain tensioner, its weird compared to the 750. Any way it got tweaked upon reassembly?

stereosilence · « **Reply #57 on:** October 05, 2012, 01:17:04 pm »

This is as disassembled as I have ever had it. So, there shouldn't be any changes from the setup I have now compared to what it was the first time I took it apart.

The only thing I can think of is if something chipped off or got down in the cam tensioner somehow. The spark plug holes are pretty filthy...could dirt have gone down in there to cause this?

Am I looking at taking the head off?

nancy · « **Reply #58 on:** October 05, 2012, 01:20:06 pm »

As i understand it - replaced cam.
So you potentially mad bad: cam to crank timing - now addressed - so assume OK;
camchain position on crank sprocket - is it properly engaged;
camchain to tensioner pulley and/or blade - slipped, wedged, stuck..whatever..dunno specifics of the 5000/500 motor;
rocker assembly.

750resurrection · « **Reply #59 on:** October 05, 2012, 01:26:13 pm »

Wait how is it that plugs 1&2 out cause no squeal, but in they cause squeal ?

I interpreted this squeal also occurred with the cam chain gear off and 1+/or2 plugs in, just turning the crank while holding the chain up somehow, meaning the valves aren't moving.

Putting in plugs 1&2 caused the squeal to appear, more so with both in.

Dirt sounds like a good theory, not sure what position the valves were in when stereosilence tried turning the crank with the cam gear off and the plugs in.

Am I following sterosilence ? What did I get wrong.

TwoTired · « **Reply #60 on:** October 05, 2012, 01:31:13 pm »

Did you back off and lock the cam chain tensioner (in full slack) while doing the cam chain install?

I'm thinking the cam chain got off the tensioner "shoes" when there was slack there. And it can't find it's way back while under tension. Or, a shoe fell off.

Look down in the cam chain tunnels tunnel with a strong light and an inspection mirror to see if the chain is routed onto the shoes.

stereosilence · « **Reply #61 on:** October 05, 2012, 01:38:09 pm »

That's very possible. I had the chain off the sprocket just hanging on the cam. Should I take the cam off again and try to get down in there? Not knowing what the shoes look like, how do I get it back on them?

Scott S · « **Reply #62 on:** October 05, 2012, 01:51:03 pm »

I can still hear the squeak when you're turning it over w/o the plugs. It just happens more quickly. It makes a longer squeak when the plugs are in b/c you have some compression and you're turning the engine over more slowly.

My guess is that something is rubbing on the cam chain tensioner. Did you loosen the cam chain adjuster lock nut and turn the slotted screw ~90 degrees clockwise when installing the cam? This releases tension on the cam chain. Are you sure the chain is riding on the guide and the tensioner?

TwoTired · « **Reply #63 on:** October 05, 2012, 01:56:31 pm »

Remove all the tension from the tensioner and lock it in that position.
Position the cam sprocket so that a lobe cutout is pointing upward. (I think that is the "book" alignment position, but it's been a while.)

Remove the cam sprocket, and then remove the chain from the sprocket. Hold the chain up so the side are as narrow as can be.
I'd still look down into the cam chain tunnel depths to see how thing sit or are situated.

If it all looks like things are in the right place, hold the sprocket near it mounted position while placing the chain on it, so the chain will be in its run position during install and "fall" into it's old place when it ran before.

Remount the sprocket (in proper book alignment) and then position the crank so slack side of chain is on the tensioner side (15 degree post), release and lock the tensioner nut.

Now turn the engine and listen for the noise. It shouldn't make that noise and I wouldn't run the engine without discovering cause.

Are you reasonably certain you don't have any bent valves from prior assembly? Can you push on them to compress the valve spring and move the valve inward? (Just a thought.)

750resurrection · « **Reply #64 on:** October 05, 2012, 02:02:34 pm »

Quote from: Scott S on October 05, 2012, 01:51:03 pm

I can still hear the squeak when you're turning it over w/o the plugs. It just happens more quickly. It makes a longer squeak when the plugs are in b/c you have some compression and you're turning the engine over more slowly.

My guess is that something is rubbing on the cam chain tensioner. Did you loosen the cam chain adjuster lock nut and turn the slotted screw ~90 degrees clockwise when installing the cam? This releases tension on the cam chain. Are you sure the chain is riding on the guide and the tensioner?

Yes, okay I thought his first couple of slow turns with the plugs out were "residual squeal clearing up" and he turned it faster a number of times and it didn't squeal ( to my noob ears lol )- thought it lubed out or something.

stereosilence · « **Reply #65 on:** October 05, 2012, 03:47:58 pm »

I'll give that a shot. It seems much more difficult to turn the kick start lever than before. And this is the first time I have never been able to get it to start right up. I have never heard that noise before now, and I got it from a guy who used it as a daily driver, so I don't think this problem existed before The Head Invasion.

dave500 · « **Reply #66 on:** October 05, 2012, 04:22:25 pm »

remove the chain and sprocket,now try and rotate the cam only in the head,,are any of the 650 cams larger lobes fouling in the body of the head??also lay the cam in the cover and rotate the cam aswell,make sure the lobes dont foul the cover or the back of the rocker arms.

TwoTired · « **Reply #67 on:** October 05, 2012, 04:48:22 pm »

You know, you could simply put the old cam back in and see if the noise is sill there. Just saying.

matt mattison · « **Reply #68 on:** October 05, 2012, 05:04:31 pm »

Do check for bent valves as well before re assembly at this point. Either TT's method, or pump air into the cylinders and listen. Just my .02.

phil71 · « **Reply #69 on:** October 05, 2012, 11:30:04 pm »

Noise aside, it ran poorly. That says to me that you've gotten a "tooth off" misread on the cam timing because the chain tensioner was slack and out of whack. I 'think' that shouldn't result in a bent valve on that engine.

750resurrection · « **Reply #70 on:** October 06, 2012, 09:26:18 am »

Ooooh boy - the mystery remains...

Very surprising.

Speak up stereosilence ! Where hast thou gone ? ( to the 12 pack refresh room I would guess

)

Trav-i · « **Reply #71 on:** October 06, 2012, 03:39:48 pm »

Stereo, where in Atlanta are you? I live up in Gainesville, and know a handfull of other CB owners here in NEGA. I'm more up on 750s but I do know a small bit on the 550. If you need a hand I might be able to get down your way some time. Just hit me up through here. You'll have to ride with us sometime once you get the 550 up and going again.

Travis

Dimitri13 · « **Reply #72 on:** October 06, 2012, 03:58:35 pm »

Quote from: dave500 on October 05, 2012, 04:22:25 pm

remove the chain and sprocket,now try and rotate the cam only in the head,,are any of the 650 cams larger lobes fouling in the body of the head??also lay the cam in the cover and rotate the cam aswell,make sure the lobes dont foul the cover or the back of the rocker arms.

I think dave may have hit the nail on the head. From what I've read, the 650's cam lobes have clearance issues with the 550 valve cover (and I believe head).

Killer Canary · « **Reply #73 on:** October 06, 2012, 06:06:29 pm »

Apparently the noise is present even without the cam turning.

Dimitri13 · « **Reply #74 on:** October 06, 2012, 06:39:17 pm »

Oh, my bad. Carry on then.

My vote is for pulling the head and checking for bent valves.

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Author Topic: After cam swap, won't start | Block off pics (Read 20728 times)