Topic: 1977 CB750 K7 Resto-mod, Knoxville

[AintNoEasyWay]

Alright, so I think I figured it out. I think the cam was 180 from what it should be. I rotated the cam so that #1 cam lobes were facing down. I think this allows the #1 IN & EX valves to be closed, which would be on the compression stroke. Meanwhile, if you look over to #4, the EX lobe has just passed & you're coming up on the IN lobe, for the air/fuel mixture to come in from the carbs.

Once I changed the cam 180 from what it had been, I was able to set the rocker arms as the manuals say. Does this sound right to everybody?

Thanks, calj737 for pushing me to learn this on my own.

[calj737]

To confirm this, remove spark plug 1&4 and gently poke a dowel into the chamber, and touch the top of the piston. Compare the depths. Nothing else is absolute proof.

This is a trick from when you assemble a motor, a depth gauge to establish the true TDC of a piston. Use that method, then set your timing marks on the crank. If you establish a mark that you know is accurate on the end of the crank, then when your cam is installed, all you need to do is line up the marks for 1 to be at TDC. You can probe the chamber with a depth gauge and then away you go.

[AintNoEasyWay]

To confirm this, remove spark plug 1&4 and gently poke a dowel into the chamber, and touch the top of the piston. Compare the depths. Nothing else is absolute proof.

This is a trick from when you assemble a motor, a depth gauge to establish the true TDC of a piston. Use that method, then set your timing marks on the crank. If you establish a mark that you know is accurate on the end of the crank, then when your cam is installed, all you need to do is line up the marks for 1 to be at TDC. You can probe the chamber with a depth gauge and then away you go.

Ok, I'll check again when I get back home. Thanks.

Does anyone have advice on how to remove the center shaft seal in the oil pump? I got a new one from Elan, but the old one refuses to budge at the moment.

[AintNoEasyWay]

Nevermind, found a method here: http://forums.sohc4.net/index.php/topic,36459.msg1681203.html#msg1681203

Thanks, MCRider!

[AintNoEasyWay]

Well, not much luck trying the Hondaman/MCRider trick. Definitely scary drilling the shaft seal because it's hard to tell when you're about to go all the way through the seal. Sprayed some PB blaster around it to let it soak after I heated it up a couple minutes with a hair dryer. Guess I'll check it again in the morning. Any tips until then are appreciated!

[AintNoEasyWay]

Still not able to remove the center shaft seal. My Dad & I put that part of the pump in the freezer for overnight & will try hitting it with a heat gun tomorrow. Maybe that will be enough to get it out. Wish I had just left the original in!

Meanwhile, just cleaned up my spokes & sanded/polished up my forks. Amazing what some sandpaper, steel wool, & a little mothers polish can do to clean things up.

[AintNoEasyWay]

Alright, center shaft seal is out. I'll get the oil pump back in the engine tonight. Going to do one more check on the pistons as cal recommends above, then I'll close up the engine & strip paint, degrease, & prep for paint. I'm going to spend the next couple nights on that since I've read prep is the most important part. I've degreased the engine a few times since it's been out of the frame, but I have no idea how much clean up there will be after paint strip. Excited about getting everything finalized.

[AintNoEasyWay]

Engine is done. Time to paint.

[Restoration Fan]

AWESOME!  Getting close to riding time now, Nate.

[AintNoEasyWay]

Stripped paint tonight. Holy $&@! What a mess! Managed to get most of it off, but I'll go back over it tomorrow evening with brass brushes & scotch pads. Then I'll have Friday night to do a few more degreases & wash downs. I plan to use Saturday & Sunday for paint.

[AintNoEasyWay]

Ok, went over the engine with brass brushes & a red 3M sanding sponge I had. That shined up the engine really well & got pretty much all of the remaining paint off. Then sprayed on degreaser & rinsed down with a hose. Went over all of it with the air compressor & some towels to get it all as dry as I could.

Hopefully any remaining water will dry overnight. I will wipe down with acetone tomorrow at lunch, then go ahead & spray the primer coats tomorrow evening. Hope I've done enough prep & I'll have a successful paint job for a long time!

[SOHC4 Cafe Racer Fan]

Give it 2-3 wipes with acetone.

[AintNoEasyWay]

Give it 2-3 wipes with acetone.

Hey Cafe Fan, thanks for the input. I found your old thread on engine paint here: http://forums.sohc4.net/index.php?topic=114550.0

Did you end up using a process similar to what MadScientist describes in that thread?

[AintNoEasyWay]

I'll be using VHT primer, paint, and clear on the engine. All of them are high temp up to 550 degrees fahrenheit.

Since I'll be spraying the engine while it's all together, I was considering using a heat gun before and between coats to help the paint dry properly (I don't have the option to bake pieces in any kind of oven). Has anyone tried this?

[Restoration Fan]

Nate,
See if you can find a large cardbox box that's a good bit larger than your engine.  Line the interior of the box with aluminum foil and then make a hole in the side of the box large enough for you to safely put the heat gun through into the interior of the box.  If you really want to be clever, take a kitchen thermometer and stick it through to the interior of the box so you can see just how high you're getting the interior of the box.

That should be more than sufficient for you to get even heat onto the engine and cure the VHT paint because it doesn't require a super high heat.  I think it's just like 240 for an hour or something like that.

Question:  are you planning to paint the valve cover?   If  you're not taping that and are going to paint those, then you should loosen your tappet covers.  Leave them on so you don't get paint inside the engine but you wanna make sure those don't get painted shut.

[AintNoEasyWay]

Nate,
See if you can find a large cardbox box that's a good bit larger than your engine.  Line the interior of the box with aluminum foil and then make a hole in the side of the box large enough for you to safely put the heat gun through into the interior of the box.  If you really want to be clever, take a kitchen thermometer and stick it through to the interior of the box so you can see just how high you're getting the interior of the box.

That should be more than sufficient for you to get even heat onto the engine and cure the VHT paint because it doesn't require a super high heat.  I think it's just like 240 for an hour or something like that.

Question:  are you planning to paint the valve cover?   If  you're not taping that and are going to paint those, then you should loosen your tappet covers.  Leave them on so you don't get paint inside the engine but you wanna make sure those don't get painted shut.

Very solid advice. Thanks, Ron! I'm going to leave the cam cover polished but paint that angled piece that sits in the very center of the cam cover. It has three screws on the outside and two that go beneath it into the cylinder head. Not sure what it's called.

I'll probably use that as a test piece for paint before I begin going over the whole engine, since it's so small. I'll tape up the cam cover while painting. I assume the paint tape will hold up in the make shift oven?

[SOHC4 Cafe Racer Fan]

Did the repeated acetone wipe downs. I recommend the hot box even though I didn't do it. Someone came up with the foil-lined box later. Really great idea.

[Restoration Fan]

I'll probably use that as a test piece for paint before I begin going over the whole engine, since it's so small. I'll tape up the cam cover while painting. I assume the paint tape will hold up in the make shift oven?

I don't know if it will or not.  That tape is paper-based so it might burn.

[AintNoEasyWay]

I had a red scotch brite pad out to go over my engine last night & saw my dirty, rusty headers sitting in the corner. Figured I'd use the pad on those too while I was at it. The headers cleaned up really well to my surprise. The black is a little dull though, so I'm considering still repainting them. What do you guys think? My engine will be black as well so I don't want any major contrast between the too. I'll just have to see once I paint the engine.

If I repaint the headers, does the original black need to come off completely or can I paint over that once I've sanded & prepped with some kind of solvent?

Either way, I really need to clean up/de-rust these exhaust collars to get them looking nice. Those stoppers that prevent the collars from coming off (pictured to the right of the collar in the photo below), what are they called & how do I remove them? They seem to just bend off from one side if I pull them off, but I'm not sure & don't want to damage them. They are also pretty damn rusty.

[Restoration Fan]

Nate,
Those little pieces that fit underneath the exhaust collars should be 2 separate pieces.  They should just separate and pull right off.  Put a scotch brite pad on your drill or one on your Dremel and you should be able to sand the rust right off them. 

Or you can purchase a gallon of Metal Rescue and put them and the exhaust collars into it.  It'll take that rust right off of it all.

Regarding your headers, I personally think they look fine as they are but if you want to paint them, just make sure there's no flaking or missing paint.  If there is, you should probably put some stripper on them and remove the paint before spraying them.  If the paint on there is in good shape, just give it a light sanding with some rough grit sandpaper to give the surface some tooth for the paint to grab onto.

[Wobbly]

If they are too far gone (yours are trashed), you should just replace the exhaust-pipe-joint collars. They are still available from Honda (8 x part # 18233-392-000). The joints should clean up okay.

[madmtnmotors]

The collars for the Mac headers are different than the stock collars....

[AintNoEasyWay]

Damn, the stock pipe-joint collars are insanely expensive!

madmtn, if you're right, I'll have to find ones for the mac. Maybe I can get a better price on those.

[Wobbly]

Damn, the stock pipe-joint collars are insanely expensive!

Think so? Wait until they are no longer available from Honda, and then check prices.

[Wobbly]

$ 9.32 a piece at Discount Honda. http://www.discounthondaparts.com/fiche_section_detail.asp?section=2451916&category=Motorcycles&make=Honda&year=1977&fveh=131105

But , indeed, the stock spacer collars won't fit on the MAC pipes.