Author Topic: My 1ST ever K7 Build with 0% knowledge and 110% determination (Read 5531 times)

seanbarney41 · « **Reply #25 on:** August 18, 2017, 09:23:28 am »

the only way to smooth those welds is to remove metal...that is a no no. These frames are not that strong to start with...VERY thin walled tubing. It can be done by adding body filler, but thats a hack unless you are building a chopper.

Please don't misunderstand, I really understand your enthusiasm and determination...but you may want to learn how to ride on a stock motorcycle. Then you will be able to better determine if changes are really an improvement or just the destruction of a cool old bike.

fiascoelment · « **Reply #26 on:** August 18, 2017, 09:59:48 am »

nvr2old- I see, then I will consider the paint route, I may just turn to a body shop to do so.

seanbarney41- Noted. and no worries thank you for the advice, I completely understand what you are saying as I had a chance to snag a 77 CB750F2 to learn on, but that was sold. So for now until another deal like that pop-up then I will continue and thread lightly with this project.

Also for the engine rebuild, since not much is going on at work I decided to create an .xlsx file for its schematics, so far I have done the cylinder cover, and head. Please let me know if this has been done, or if I should continue to do the entirety of a CB750K7, my sources so far is CMSNL

calj737 · « **Reply #27 on:** August 18, 2017, 10:14:05 am »

There is a brand of filler suitable for use with powder coat, but you should inquire with your powder coater about it. And you would want to use it after they blast your frame clean else they blasting process will simply remove the filler.

The factory welds are crap. Best thing to do is have someone you know with some TIG skills wash over them and add filler to clean them up and make them beautiful. Then powder coat.

As for cleaning the engine cases, Simple Green works, elbow grease, even Oven Cleaner (though it will turn the cases a dark grey). Since you plan on painting the cases, a decent prep job and primer and quality rattle can paint can look pretty good.

Stev-o · « **Reply #28 on:** August 19, 2017, 07:12:42 am »

Personally, I never use a pressure washer on my bikes, I dont like introducing water to them.

I use Gunk Foamy Engine cleaner and acetone to clean before paint.

No sense vapor blasting before paint [fairly expensive], bead blasting would be more cost effective.

fiascoelment · « **Reply #29 on:** October 11, 2017, 05:04:37 pm »

Finally got to touch my motor after sometime, my schedule has been hectic lately and last night I was able to get around to opening my motor. I got as far taking the off the Cylinder Head.

When I took of the Cylinder head cover, camshaft, rocker arms everything seems to be clean. Then when I got up to the point of taking of the 22 nuts and bolts for the Cylinder Head I noticed there was what it seems to be a spider web where the spark plug is located on cylinder 3.

When I finally took of the head I came across a very dark pistons and cylinder surface and what seems to be sand and something that feels like sand, if any of this make sense, any one want to chime in

Also received my Cognito Moto Frame Loop and Cowl I have a picture of a mock up on my current frame

I have a long way to go but I am happy I can get back to this without losing interest. I won't be posting regularly but I will still keep this up and look for advice along the way

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Maverick · « **Reply #30 on:** October 11, 2017, 08:28:05 pm »

Every thing is looking great! And that black sandy stuff is carbon build up. No fun, but if you carefully clean it and check that your valves seat properly, it should be all right

fiascoelment · « **Reply #31 on:** October 11, 2017, 08:58:46 pm »

Thanks maverick ! Yeah since this is my first ever build I'm going try to be as thorough as possible here some more closer pictures of the Cylinder walls

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fiascoelment · « **Reply #32 on:** October 11, 2017, 08:59:28 pm »

+misc pictures

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fiascoelment · « **Reply #33 on:** October 17, 2017, 04:29:08 pm »

Hi Guys,

Im in need of your help. So I am trying to get the Cylinder Block separated from the case. Anyone know an efficient (non back breaking way) to get this off.
I have read the cotton rope in the cylinder trick, any one want to elaborate on that?

As much as possible I don't want use brute force.

Please let me know.

Thanks,

VT

calj737 · « **Reply #34 on:** October 17, 2017, 09:23:00 pm »

The cotton rope trick only works for the head attached. Essentially, you stuff rope into the cylinders to act as a spacer/buffer. When the crank is rotated, the piston pushes the bottom of the head up and away from the cylinders. Problem is, your cylinders are stuck, not the head.

There's a thin area at either end of your block that you can use a thin, stiff shim to help initiate the block to separate from the cases. Inspect that seam to see if a PO used a gasket sealer or adhesive to stick the parts together. If not, some heat, a bit of wiggling, some patience, and some prying and they will separate.

I have found it to be helpful (if possible for you) to have someone rotating the crank while I pry/lift. Makes breaking the seal a bit easier when the pistons are moving slightly.

fiascoelment · « **Reply #35 on:** November 04, 2017, 11:28:38 pm »

I was finally able to separate the block from the case here some pictures of my motor next im going to inspect the pistons and see if they are still good. I am getting closer to disassembling this thing down to the case! Any advice from here on?

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fiascoelment · « **Reply #36 on:** November 04, 2017, 11:29:58 pm »

Here are the cylinders, from the who are experienced can you tell the condition from there's pictures?

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calj737 · « **Reply #37 on:** November 05, 2017, 04:28:21 am »

Remove that head gasket, and you’ll get a better view into the cylinders. At this point, I’d certainly remove the pistons and have the bores measured before reassembly. Best case, a fresh hone if they measure within spec.

fiascoelment · « **Reply #38 on:** April 19, 2018, 10:24:53 am »

Hi guys,

I havent made much progress since I last posted but here I am still standing tall. I followed some of you guys here and got a harbor freight engine stand and fab up brackets to be able to mount them. Please let me know if I can get away with this mount without having the engine fall on me foot

. I found it to be a little shaky maybe because of the lack of support on the other half of the engine.

I am now trying to split the case so I can inspect and maybe change the crank bearings, rod bolts and send the case for vapor blasting.

Any other things I should look out for to change or inspect while/when the case is split?