Author Topic: 1975 CB750 Build! "Kona" - Sold and gone. (Read 71063 times)

Ravie · « **Reply #225 on:** January 24, 2015, 08:33:12 PM »

I keep finding things to do to the CB that don't cost any money.

Tonight I:

-Cleaned and degreased the oil pump. Put a new O-ring on one of the spring caps, lightly oiled it and reassembled it

-Did some more degreasing of the lower case half. Took it to the car wash but the one I went to uses cold water so it didn't do much good (cheap bastards..). Bought some engine degreaser and did a better job by hand. Letting it soak now.

-Re-beveled the bottoms of the cylinders since the 836 bore-out removed all of the old bevel. Dremel and 2000 grit did the job.

-Removed some of the sharp casting around the oil return holes in the head. I didn't go crazy, just lightly rounded over the holes.

-Removed the old Steering stem and head races to make way for the eventual tapered bearings.

-The K3 tank I got from a fellow forum member... I thought the inside had some light rust so I poured in a gallon of vinegar and a bit of CLR. Added some nuts/bolts/screws and began to clean it. Turns out it has been coated before and what I thought was rusty crusty stuff was actually failed coating. Not a big deal but it's gonna be a bit of a PITA to remove. I'll leave that mixture in there for a few days and since I'm sure it won't remove it all I'll do something stronger next. Any recommendations? The Works? Acetone? I don't think it was lined because it leaked. I think someone just did it for S&G's. Granted it turns out OK I will probably NOT line it again.

Side note to the tank: my wife wrecked her car last August (her fault, unfortunately) and I've got a guy who wanted to buy it...we did some haggling and as part of the deal he is going to paint my tank for me. Yay! His shop does great work and he's a very nice fellow.

So...Got some more stuff done anyway!

calj737 · « **Reply #226 on:** January 25, 2015, 04:58:11 AM »

Drain your tank of the vinegar and CLR. Then replace that with Acetone. Let soak. Drain and filter the acetone as you pour it out and re-use it. Don't forget to invert the tank and allow the acetone to work on the underside of the top.

You've created a job for yourself to remove that liner... Be patient, keep draining and refilling the tank. It will all come out but you need to be diligent to get it all out. And acetone isn't cheap, but it's what you need to get that out- and be mindful, acetone will eat the paint straight off your tank!

Restoration Fan · « **Reply #227 on:** January 25, 2015, 05:43:41 AM »

Quote from: calj737 on January 25, 2015, 04:58:11 AM

Drain your tank of the vinegar and CLR. Then replace that with Acetone. Let soak. Drain and filter the acetone as you pour it out and re-use it. Don't forget to invert the tank and allow the acetone to work on the underside of the top.

You've created a job for yourself to remove that liner... Be patient, keep draining and refilling the tank. It will all come out but you need to be diligent to get it all out. And acetone isn't cheap, but it's what you need to get that out- and be mindful, acetone will eat the paint straight off your tank!

Also make sure you're in a well-ventilated place or wear a mask because that acetone will get you floating if you breathe it enough.

Ravie · « **Reply #228 on:** January 25, 2015, 06:55:58 AM »

Well thankfully the tank hasn't been painted yet and the paint that is on it is in terrible shape, so I'm not worried about that. I'm doing all of this treating now before it has been painted.

I think the stuff that is in it was probably that Red-Kote people use.

I was thinking probably Acetone. Cool.

That liner was already flaking off, so I'm not sure I "created" the job...it was going to have to come out regardless of my mucking around with it. I just "helped" it. :-D

calj737 · « **Reply #229 on:** January 25, 2015, 06:57:37 AM »

Be prepared when it comes out to discover some pinhole leaks. And also be dead certain to remove any rust that was left beneath it. That's the time for the Works cleaner or vinegar treatment.

Re-line it with Caswell for best results.

Ravie · « **Reply #230 on:** January 25, 2015, 07:06:32 AM »

Caswell eh? I had my eye on POR-15 a while back. You think Caswell is more proven?

Yeah, I'm prepared for that. The CX500 tank I had had LOTS of pinholes in it, so if this one only has one or two...it'll still be better than that one.

calj737 · « **Reply #231 on:** January 25, 2015, 07:28:07 AM »

I have been exceptionally impressed with it.

edwardmorris · « **Reply #232 on:** January 25, 2015, 09:52:18 AM »

K3 tank? If you're talking about the one from me, its a K2, but yea, sorry for your troubles, the PO on that bike was exceptional. It had gas in it as long as it was here and I had no idea it was coated. When I emptied and dried it for shipping I really couldn't tell or I'd have let you know. Hope you figure it out though, good luck. Worst case, there's another tank with some psychotic paint sitting on my K3 that you can have. I still haven't braved to remove that duct taped gas cap and peek inside

Ravie · « **Reply #233 on:** January 25, 2015, 11:39:45 AM »

Ok, I couldn't remember. Yeah it's not a problem. It was an even swap in my head even with the PITA of that coating. I went and got some Acetone at Ace and I've got a bunch of drywall screws and other various nuts and bolts in it now. I'll gitrdone. Just gotta do the cha-cha a bit in the garage. Good thing I've got a Pearl Jam tape and a SRV CD in there... hahahaha

Hey Cal - Here's a video of the last show we did before we quit for over a year.

That's me on the git-fiddle.

Rav

Ravie · « **Reply #234 on:** February 01, 2015, 01:26:27 PM »

How would you jet this setup(?):

836 flat-top pistons
Minor head porting (just massaging the angles a bit)
D8ES plugs planned
2-2 Exhaust system with internal baffling
Stock air box, possibly a K&N filter.

Right now I've got 105's in there which I think will be too small. Maybe 115's would be better? I know there will be some trial and error but I'd like to start with the best jet size I can.

Also, the newer replacement jets look different...will they work as well? Why don't they have the little emulsifier tubes on them like the originals do? I feel like I'm at a kindergarden level of understanding Honda Keihins right now.

edwardmorris · « **Reply #235 on:** February 01, 2015, 02:05:04 PM »

Mark's book has an excellent chapter on the insides and out of the carbs and jets, give it a try. Post up some pix of the exhaust you want to use, big factor in deciding on the jet size. For 836, I haven't read of any that use smaller than 120, but again, exhaust might change that

Ravie · « **Reply #236 on:** February 01, 2015, 02:30:41 PM »

I figured out why I was confused about why the replacement jets looked like they didn't have the emulsion tube for the needle jet...because they're TWO PIECES. Mine gave me no indication that those were two different parts and the main jet was actually screwed into the needle jet holder. I went to a motorcycle show today and bought a nice unused Clymer manual and was looking at the parts diagram and figured that out. WOW.

Yeah I've read his carb chapter. I'll go snap some pics and be back.

Man I feel dumb. lol

Ravie · « **Reply #237 on:** February 01, 2015, 03:18:08 PM »

Alright, here are some crappy pictures of my exhaust. I have another one too that is also a 2-1 setup but it's ugly. I like this one better. I have the worlds crappiest Nikon. Sorry.

Also pictured is the float needle I was telling Cal about on the phone the other day. spring loaded nipple.

I suppose I could drill those holes bigger on that baffle plate if I felt like it.

Ry

Ravie · « **Reply #238 on:** February 02, 2015, 08:03:54 AM »

Really wish I could tag folks in threads so they'd know to come in here with their knowledge!

Went to a show in Lawrence, KS yesterday. A few really nice bikes. Man those 70's Ducatis are sexy. Managed to pick up a nice Clymer manual. Between that and Marks book I've got lots of good info now!

Sent from my Venture using Tapatalk 2

edwardmorris · « **Reply #239 on:** February 02, 2015, 08:40:32 AM »

Float needle is toast.

Factory manual is a better companion for HM book, Clymer and others are known to have errors (from what I read here, I don't have one on hand).

Exhaust looks a bit too restrictive, is it the only option?

Ravie · « **Reply #240 on:** February 02, 2015, 10:25:13 AM »

Toast? That's not the needle end..not as dirty as it looks in the photo...

I have another exhaust but its not as nice looking. Ill pull it out. Why not just drill this one bigger?

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Yoshimoto · « **Reply #241 on:** February 04, 2015, 06:18:05 PM »

Quote from: Riceman on January 21, 2015, 07:49:52 PM

Quote from: Ravie on November 12, 2014, 10:52:45 AM
This has to be the most boring build thread ever.

On the contrary,I have just read the entire thread...
quite enjoyable,entertaining,and Ralph Nader sucked!

When I was a little younger, I contributed $25 to Ralph Nader's campaign fund because you got a free t-shirt with the donation. I then wore the shirt to my parent's house just to push my Dad's buttons. Worked like a charm. 25 bucks well spent.

Ravie · « **Reply #242 on:** February 16, 2015, 06:46:04 PM »

I don't remember mentioning Corvairs. Maybe I did in my first post. I am a late model Corvair lover. I had a 65 that was fully rebuilt by myself that was the most fun car I've ever had. I sold it to make time for babies rather than garages. 140 bored 40 over, decked, a little bit hotter than stock cam, KB forged pistons, magnetic ignition, headers with stinger mufflers... It was one hot car. I sold it for about what I had into the motor alone.

Anyhoo...

Some things I have decided on that are a bit different than originally planned:

Dunlop K70 tires. Boring and vintage. Stock sizes. I was going to use the 16" Harley rim I have for the fatter tire but have officially decided against it. Too many people talk about it effecting the handling and the fat tires barely clearing the chain, etc.. The K70 is a classic tire with great reviews and I think it looks neat.

Handlebars: I'm doing clip ons. They'll be higher than the clubmans that came with my bike, but lower than even the renthal ultra-lows I talked about maybe going for. Part of the reason for this decision is because:

Rearsets: I'm going to get Devin/Cognito rearset brackets. Not sure what I'm doing for hardware there. Definitely not the 400 dollar ones they sell. I'm sure they're great but...youch.

For now I'm going to stick with stock wiring. I managed to fix my original wiring harness. I think the M-Unit is in my future but for now I'm going stock to keep my budget in check a bit.

I started to futz with my head doing some removal of the casting lines in the bores, etc.. but decided I don't really have the right stuff to get it done right...so I think (I'm waiting on a price list...) I'm going to send it to Mike Rieck and have him do his magic.

I'm gonna use the exhaust system I posted before. The one I painted black. If I find that the rear baffle plate is too restrictive, I'll drill the holes bigger. If I get rich I'll ditch it all and by a Mac 4-1.

I'm trying to decide if I want to stick with stock style coils or go for the Dynas. My plan is to get a transistor ignition from Mark and use good ol' points. I like the Dyna coil for it's ability to change plug wires. My plan is to run D8EA plugs.

A few issues I need to research more: I know it is said you need new sprockets with new chains...but my rear 48 tooth sprocket looks really good. grr. I've read some conflicting advice about this. I get that if your sprocket is worn that it could spell trouble for wearing in correctly with a new chain, but...I dunno. The front one needs changed...it's just nasty. Someone give me some definitive advice here! please!

I wasn't originally going to install the center stand. I am now. I've already wire brushed and sanded and painted it to match the frame.

That's all I've got for now. :-)

Ravie · « **Reply #243 on:** February 20, 2015, 04:51:03 PM »

It's funny, you know...the further I get into my build, the more stock it becomes, as I try to "trim the fat" on my budget.

To get running and riding I've decided to skip the rear sets and clip ons for now and go with stock bars. This will also allow me to use the original seat pan I have as well. I can upgrade later. I have to force myself to set my sights on what gets it running and reliable and worry about the fun stuff later, as I'm trying to keep my budget down (I keep saying that hoping it will come true...)

Are there other seats out there (or does anyone HAVE a seat...) that look better than stock...(I'm sorry stock bike lovers...but I am not a fan of the stock seats on these bikes) that are relatively cheap? I have a plastic seat pan I could use, I suppose I could bring it to someone to have them do foam and a cover.. I actually have the foam that came on the seat I have but the cover is in bad shape and it is not a stock pan or seat, so I can't just recover it with an off-the-shelf cover. If anyone has a decent seat kicking around I'd be interested in it.

:-)

Also, if anyone actually reads my thread...i'd appreciate some thoughts about sprockets in my above post.

seanbarney41 · « **Reply #244 on:** February 20, 2015, 05:23:20 PM »

definately replace the front sprocket, that is the one that wears the most, fastest. A new chain without 2 new sprockets is definitely going going to wear faster than if you had replaced all three. I have swapped used stuff around between bikes to come up with a useable combination and the chain only lasts long enough to get by in this situation. The parts will eventually mate and the wear rate stabilizes, but you need to have some "meat" to start with. On one hand rear sprockets can be had for as little as $25. On the other, my guess is you would be good for 5000 miles or so just doing the front sprocket and good quality new chain.

Ravie · « **Reply #245 on:** February 20, 2015, 05:28:55 PM »

The only rear sprockets I've been able to find online are more like 40-50-60...

I understand what you're saying.

Then there's the other issue of...I've heard from Mark as well as others that the tooth cut on most new sprockets isn't the same as the old ones and it makes the chains louder, etc... So then I think...what's the best choice?

It should not be rocket science but....

seanbarney41 · « **Reply #246 on:** February 20, 2015, 05:41:34 PM »

You might be right on the price...I am now realizing I bought my last couple sprockets through a friend that worked at a Harley dealer for cost. The Hondaman stuff is true, but will not matter unless you are really gonna be a total chain maintenance stickler. I have found for mere mortals like me, a decent quality o-ring chain is the best bet. Don't run a badly worn front sprocket, period.
Just leave the chain sprocket issue til last and try and save as much as you can before then.

Ravie · « **Reply #247 on:** February 20, 2015, 05:44:33 PM »

I can dig it. I'll be definitely doing a new 17t front sprocket and a diamond chain. I may end up getting a rear sprocket, too. i found one online that someone was selling used/new for like 18 bucks. I think I just need to keep an eye out for those deals.

Ravie · « **Reply #248 on:** February 24, 2015, 08:47:20 PM »

Well, tonight I started ordering parts. I don't just mean a few...I mean all of them. I sent my head off to Mark in CO for porting and whatever else he thinks it really needs.

I only have a few things left on my list:

Good set of points/condensers (I was hoping for Diiachi Japan...)
The 15.5" Upper Brake Hose (no one seems to have one in stock.)
Blade-type Fuse block I will buy from O Reilly and adapt for use on the bike.

Ended up getting the Dunlop K70 tires in stock sizes.

Didn't really order anything "wow" except maybe for Dyna Coils and a Biltwell flip-visor full face helmet in flat black. Everything elsse was just....parts. lol

Oh, I also went for it and ordered the universal "cafe" style seat from Hong Kong today. I looked into getting mine redone or buying a used one...and they were all basically similarly priced. I really liked the style of the eBay one so I went for it.

A buddy of mine is fixing my side covers. After he finishes them I will bringing my tank and side covers to a local guy who owns an auto body shop to paint them Kona Coffee Metallic, which he's doing as part of the payment for buying my wife's wrecked 05 Pontiac.

P-r-o-g-r-e-s-s.

calj737 · « **Reply #249 on:** February 24, 2015, 10:34:08 PM »

You don't want Daichi points, you want TEC brand. Don't make that mistake!

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Author Topic: 1975 CB750 Build! "Kona" - Sold and gone. (Read 71063 times)