Topic: CB 750K7 valve springs

[FargoFour]

I'm in the middle of rebuilding my K7's top end. When I removed the valve springs I failed to notice that they are wound differently on the top verses the bottom of the spring. There are two coils closer together on the top.  Anyway I didn't see anything about this in the Clymers manual or in a post I found here about rebuilding 750 engines.

You know where this is going. When I put the springs back on I noticed the difference and so I but the spring in with the two tight coils down and now the head is on and torqued down. Later last night I find a K8 Honda manual on line and it says "Caution, install the springs with the tight coils on the top" (or something like that).  This brings me to a bunch of questions.

1. Is the orientation of the springs critical? I mean will the engine come apart or otherwise fail?

2. If I need to reinstall them can I do this with the head on? I know there are spring compressors for "head on" work but will these work for a 750?

3. If I need to take the head off can I reuse the head gasket after it's been compressed?

4. If i have to take the head off can I buy just the head gasket?

I have a feeling I know the answer to #1. TwoTired has stated many times that the Honda engineers did thing s for a reason and I've followed his advise on lots of things on my bikes and he's been right.

thanks for any info.

Bud.

[scondon]

 At 5000rpm those springs compress at the rate of 42 times per second. I won't pretend to know, but I would think that the spring dynamics matter

 Joeb was able to pull his springs with the head on by threading his air compressor into the spark plug hole to create pressure in the chamber which was enough to hold the valve in place while he used one of those "head on" spring compressors to do the job.

 I had to pull a head that I had already torqued and wondered whether I should re-use the gasket too. I came to the conclusion that the fire ring had been compressed and I would be taking a risk by reinstalling it. Don't know if this was the case, but it made sense and I didn't want to risk it.

  Honda sells head gaskets by themselves. Dynoman and maybe Z1 enterprises also should have them.

[MCRider]

I'm in the middle of rebuilding my K7's top end. When I removed the valve springs I failed to notice that they are wound differently on the top verses the bottom of the spring. There are two coils closer together on the top.  Anyway I didn't see anything about this in the Clymers manual or in a post I found here about rebuilding 750 engines.

You know where this is going. When I put the springs back on I noticed the difference and so I but the spring in with the two tight coils down and now the head is on and torqued down. Later last night I find a K8 Honda manual on line and it says "Caution, install the springs with the tight coils on the top" (or something like that).  This brings me to a bunch of questions.

1. Is the orientation of the springs critical? I mean will the engine come apart or otherwise fail?

2. If I need to reinstall them can I do this with the head on? I know there are spring compressors for "head on" work but will these work for a 750?

3. If I need to take the head off can I reuse the head gasket after it's been compressed?

4. If i have to take the head off can I buy just the head gasket?

I have a feeling I know the answer to #1. TwoTired has stated many times that the Honda engineers did thing s for a reason and I've followed his advise on lots of things on my bikes and he's been right.

thanks for any info.

Bud.

I did swap out springs with the head on with one of those compressors. In the bike too as I had a removable frame rail kit. I just set the piston at TDC on the cylinder I was working on. Valve dropped in a skosh but not enough to keep me from doing it.

[FargoFour]

Thanks to you both.

I went and bought a head-on-the-block spring compressor from Harbor Freight for $10.

thanks again.

bud.