Topic: 1977 CB750 K7 Resto-mod, Knoxville

[calj737]

Any automotive machine shop that also deals with motorcycle engines should be more than competent to help. If in doubt, call the local Harley dealerships and speak with their service dept for recommendations on who they use.

Take the block to them. They will get it loose. If you have them, carry the pistons and rings too. Then they can bore, hone and check ring end gaps. Ask them to label each piston with cylinder number for certainty when reassembling.

[AintNoEasyWay]

Awesome. Thanks, cal.

Forgot to mention I also ordered Hondaman's CB750 book yesterday. Hopefully that'll be a big help getting the engine reassembled & running properly again!

[SOHC4 Cafe Racer Fan]

ANEW,

Not sure if you were planning on a complete engine tear down, but if you do, you should replace the primary chain while you are at it and inspect the primary tensioner, in addition to the transmission components.

[AintNoEasyWay]

ANEW,

Not sure if you were planning on a complete engine tear down, but if you do, you should replace the primary chain while you are at it and inspect the primary tensioner, in addition to the transmission components.

Hey cafe fan, I am pretty limited to a top end fix at the moment given finances. I am hoping this will see me through for a while until I can finish school & start considering a complete rebuild. Thanks for your input though.

By the way, the video you had done was awesome! I've shared it with several of my friends here & they love it too.

[SOHC4 Cafe Racer Fan]

ANEW,

Not sure if you were planning on a complete engine tear down, but if you do, you should replace the primary chain while you are at it and inspect the primary tensioner, in addition to the transmission components.

Hey cafe fan, I am pretty limited to a top end fix at the moment given finances. I am hoping this will see me through for a while until I can finish school & start considering a complete rebuild. Thanks for your input though.

By the way, the video you had done was awesome! I've shared it with several of my friends here & they love it too.

Thanks! Much appreciated.

[AintNoEasyWay]

Still no updates as of today. Tonight I'll be going to a vintage bike club meeting, Time Warp Tuesdays! It's an awesome meet up we have every week here in Knoxville. Maybe some of the guys there can point me in the right direction for a local motorcycle machine shop.

Also my Hondaman book is scheduled to arrive tomorrow, so I'm very excited to start digging into that.

[AintNoEasyWay]

Received Hondaman's book last weekend & have been reading through much of the engine section. I also got a tip yesterday for a local motorcycle machine shop, so I'm going to give them a call today.

What kind of head work do I need to plan on doing? I'm going to call them with the plan to have the cylinders miked & honed. If the miking shows that I need a rebore, I'll work from there. But I'm not sure what's considered the bare minimum for valve/head work on a top end rebuild. Lapping? Reaming? I guess I don't fully understand all these things even after reading through the forums. I'll also plan to have them check the surfaces on each side of the jugs & head to assure they're all even.

[calj737]

You certainly want them to check the springs for their specs, replace if needed. Guides need to be checked for wear, seals, and of course the valves and seats.

Optional work is to have some mild porting/polishing done up in the intake and exhaust ports to aide in flow of gases. Everything else would be specific to your motor's idiosyncrasies.

[AintNoEasyWay]

You certainly want them to check the springs for their specs, replace if needed. Guides need to be checked for wear, seals, and of course the valves and seats.

Optional work is to have some mild porting/polishing done up in the intake and exhaust ports to aide in flow of gases. Everything else would be specific to your motor's idiosyncrasies.

Exactly the advice I needed. Thanks, calj.

[SOHC4 Cafe Racer Fan]

You certainly want them to check the springs for their specs, replace if needed. Guides need to be checked for wear, seals, and of course the valves and seats.

Optional work is to have some mild porting/polishing done up in the intake and exhaust ports to aide in flow of gases. Everything else would be specific to your motor's idiosyncrasies.

Exactly the advice I needed. Thanks, calj.

Yes. Excellent advice indeed.

[enwri]

Any news on your bits at the shop? I hope you're not losing your enthusiasm about it all, when it's all over and you're riding around, you'll have the knowledge, pride and attachment to it that you only get by going through this stage.
 

[AintNoEasyWay]

Hey enwri, thanks for checking in. I tried contacting the machine shop last week, but the phone just rang & rang. I've been very busy with school, work, life, etc. & the bike has hardly gotten any attention in the past two weeks. Really I've only managed to read through more of Hondaman's book...

Financing the rebuild is also a constant issue. I took the time to calculate all the new parts I still need: gaskets, rings, o-rings, dowels, pins, valve stem seals... over $300 this is a conservative estimate, assuming I don't need new valves, guides, etc, & of course, doesn't include machine shop work. For a guy in my position, it's a lot of money...

BUT, your comment gave me a nice kick in the arse. Reminded me of why I'm doing all this in the first place! Also got me imagining myself back on the road, feeling free. Time to start taking this seriously & digging in the couch for pennies.

[SOHC4 Cafe Racer Fan]

That's when you start looking around the house and garage looking for stuff you don't touch anymore that you can Criagslist.  I've done it before to get new toys!

[AintNoEasyWay]

The local machine shop is able to mic my cylinders for free and will hone them for $12 per cylinder. I am going to check a lot of measurements tonight & will see what other work I'll need them to do. I only have a digital caliper though & an old set of feeler guages; nothing advanced like a 1" & 2" micrometer or bore gauges like Hondaman recommends. I'll do what I can with the tools I have for now.

I plan on testing the valves for leaks tonight as well.

Cafe Racer Fan, you're exactly right. As a college student, I've had several instances where I had to gather old things around the apartment & make a few quick sells on eBay.

[AintNoEasyWay]

No leak from my valves after flipping the head & letting penetrating oil sit in the chambers sit for about 20 minutes. This is a good sign I guess? I still have to take everything apart anyway to clean up the valves, check the guides, replace valve stem seals...

Taking my engine to the machine shop tomorrow! No idea how long things will take, but hopefully I hear back from them after they check measurements & all I need is a hone. Then I can go ahead & order all the remaining engine parts I'll need.

It's getting chilly here in Tennessee. I'm starting to look more at just working on the bike through the winter & having it perfect when spring comes. I'd like to do other things besides redo the top end. I want to replace swing arm bushing, front & back wheel bearings, rear brakes, steering bearings, & put a new front disc brake on the bike.

[AintNoEasyWay]

Forgot to mention, I've started making a little extra side cash by helping a local vintage collector keep all his bikes clean. Here's a CB350F I cleaned up this past Saturday.

[AintNoEasyWay]

What solvent/tools should I use to clean up my engine parts? For example, I'm not sure what to use to clean up my pistons or to remove head/base gasket residues. There is a lot of grime on my pistons, should I soak them in something?

Thanks!

[enwri]

That sounds like a cool way to earn a bit of cash, does he have anything other than Hondas? (not that there's anything wrong with having just hondas) There were some interesting ideas tried out over the years. The valve testing is a good sign as well, see if you can borrow a spring compressor that will fit the 750, not all do. search the threads, can usually make a tool to make the ones that don't fit work, (a piece of pipe cut out a bit so you can reach in with a magnet or something to get the collets out) You can even use a G clamp with your new tool, if you have three or more hands and ninja fingers.
 I know you will anyway, but keep all the bits matched up to go back in the same places.
Then you can check the valve seating surfaces for width, I don't know exactly how wide, someone will, generally should all be very similar. There wil be the guide clearances as well, too small for me to measure, as long as the valves don't wobble too much, also in here somewhere will be a thread about just how much they should or shouldn't. It's not a very high mileage engine is it?  They usually last a long time, (unless you have an F3? I think, something about different angles or something)
Not sure what people use to dissolve the gasket material, but paint scrapers or razor blades are going to be handy, obviously no gouging. soaking the pistons is a good start, the back edge of hacksaw blades are handy, be careful not to enlarge the ring lands if you use a wire brush wheel to clean the tops. the square end of a broken ring will be perfect for cleaning the lands out.

I don't know how people survive in cold places, I've got the flanno and jeans on at anything under 25c (77f).

found this     http://forums.sohc4.net/index.php?topic=137876.msg1556659

[AintNoEasyWay]

That sounds like a cool way to earn a bit of cash, does he have anything other than Hondas? (not that there's anything wrong with having just hondas) There were some interesting ideas tried out over the years. The valve testing is a good sign as well, see if you can borrow a spring compressor that will fit the 750, not all do. search the threads, can usually make a tool to make the ones that don't fit work, (a piece of pipe cut out a bit so you can reach in with a magnet or something to get the collets out) You can even use a G clamp with your new tool, if you have three or more hands and ninja fingers.
 I know you will anyway, but keep all the bits matched up to go back in the same places.
Then you can check the valve seating surfaces for width, I don't know exactly how wide, someone will, generally should all be very similar. There wil be the guide clearances as well, too small for me to measure, as long as the valves don't wobble too much, also in here somewhere will be a thread about just how much they should or shouldn't. It's not a very high mileage engine is it?  They usually last a long time, (unless you have an F3? I think, something about different angles or something)
Not sure what people use to dissolve the gasket material, but paint scrapers or razor blades are going to be handy, obviously no gouging. soaking the pistons is a good start, the back edge of hacksaw blades are handy, be careful not to enlarge the ring lands if you use a wire brush wheel to clean the tops. the square end of a broken ring will be perfect for cleaning the lands out.

I don't know how people survive in cold places, I've got the flanno and jeans on at anything under 25c (77f).

found this     http://forums.sohc4.net/index.php?topic=137876.msg1556659

Hey enwri, glad you're back around. Yes, the collector I've been working for has all types of vintage motorcycles, Matchless, BMW, Norton, Yamaha, a CB750, 550, & 350, an Ariel. He is mostly partial to British bikes.

I bought a spring compressor from Sears, but it's a total POS & I plan to return it this weekend. It is not a motorcycle specific spring compressor, but the design should permit it to work on both cars & bikes. Unfortunately it is very poorly made. I'll have to find another alternative. I may just take my cylinder head over to the machine shop as well. My worry is that they won't, like you say, keep everything in exact order & put it back in its proper place. I want to be absolutely I put everything back properly & don't create any undo wear on parts.

Thanks to Hondaman's manual, I have the proper specs for the valves, & really everything in the engine.

[enwri]

BSA M20, This came apart much easier than the cb, the crank started to take itself apart, he said it started making a funny noise after hitting 70 miles an hour down a hill, still went for months afterwards. not as user friendly to ride. people say the cb brakes aren't that good, try this thing.

Best part, an old bloke not 10km's away just happened to have a serviceable 65 year old crank lying in the dirt up the back of his garden shed, "you never know when you'll need one" he said.

[AintNoEasyWay]

Ended up taking my engine to a shop outside of Knoxville, TN called Rising Sun Cycles. The owner is a member of the same vintage motorcycle club I'm a member of here in Knox.

They just called me back today: I'll be ok with just an engine hone, but need some head work done -- intake valves are beat up & need to be replaced, exhaust valves are ok. They will clean up the seats & install new valves, plus do the necessary machine work for $390. They seems pretty steep given what a place like CycleX would do, not including shipping it over there.

But I do feel right going with Rising Sun. I'll still have to install the piston rings & button the engine back up myself. What do you guys think though?

[calj737]

$390 seems pretty darn reasonable actually. Perhaps not if you take literally to only "replacing valves (pretty minor) and re-cutting seats ($150-$200) and other necessary machine work".

But that list of services probably includes some milling, decking, honing, and maybe a touch of port polishing. Not to mention any disassembly, cleaning or reassembly.

For comparisons sake, a Serdi valve job alone is $250. That does not include any other work whatsoever.

Just a little input...

[AintNoEasyWay]

Nice, maybe I'm better off than I realized! They should have everything ready by the end of next week. I've got to do a lot of bike detailing to earn some more cash this weekend to pay for it all, but I'm excited

[enwri]

It's happening! Wait...what? Why am I excited...   I'm gunna go do something unnecessary to mine...

[AintNoEasyWay]

Haha, have some fun enwri. It's 5 celcius here this right now & could snow some over the weekend...