Topic: Put a new head gasket on, now the bike wont start

[MgMt CB550K]

Hey guys I just replaced my head gasket and I was planning on moving towards the points and condensers next but after getting it all back together I wanted to start her up and see how she was running.  The bike was running before I did this work.  But once I got everything back together with new plugs and a new air filter she wont start.  I  know for a fact that I am getting spark in 1 & 4 cylinders and gas should be getting into the carbs because one of the bowls was leaking a bit because I didn't tighten the screws enough.  I'm not sure if I am missing something after putting the cam chain and everything back together.  I tried some starter fluid into the air chamber just to see if it would start with that but nothing.  Any thoughts?  It's a 77 CB550K.  Thanks

[sbc1320]

Easy to see if you are getting spark after choking, just pull a plug and make sure fuel got to it. Other than that either out of time on the cam or valves are way too loose to build compression.

[sbc1320]

Sorry meant valves may be too tight and letting compression out.

[bryanj]

were you VERY carefull with the rocker arms on re-assembly as per the manual? If not you have bent valves

[MgMt CB550K]

As I was sitting in bed last night I was thinking about how it is probably pretty important that the cam shaft be in a certain position as well as the crank when I connect the cam chain and everything back together in there.  This thought made it really hard to go to bed since I wanted to get up and go out to the shed and try it out.  BUT is this right?  I'm assuming I need 1 and 4 at the top of their compression strokes and the cam in a certain spot?  I think there was a notch on the cam that should probably be used for this.  Can any one shed some light on this.

[MgMt CB550K]

Well I just did some digging, found a manual, and it looks like I have answered my own question  .  It looks like I need to allign the T mark on my spark advancer to the timing mark and then allign the notch on the cam to the "cylinder head flange surface".  Sounds simple enough, I just wish I had done this the first time I took the valve cover off, or maybe even the second time! But at least I will now how to do it really well now haha.

Anyone have any pointers or tips for me?

[bryanj]

READ THE MANUAL CAREFULLY concerning re-fitting the valve cover.

As you didnt before you may already have bent valves

[MgMt CB550K]

How would I have bent the valves by putting the cover on?  Everything appeared to sit fine when the cover went on and I didn't force anything down or on.

[gregimotis]

How would I have bent the valves by putting the cover on?  Everything appeared to sit fine when the cover went on and I didn't force anything down or on.

Might want to have a look at these.  Especially the third one:


http://forums.sohc4.net/index.php?topic=29963.0

http://forums.sohc4.net/index.php?topic=29963.0

http://forums.sohc4.net/index.php?topic=33427.0

[MgMt CB550K]

OK so whats the best way to figure out if I have bent the valves or not?  Would I hear them as the engine turned over?  If this involves removing the valves what special tools will I need?

Although I am pretty sure that I did not bend them since I had some helping me place the cover on and we were holding the tappets up from the tappet holes.  That was really the olny way we could get it to sit correctly before we started bolting it on.