Author Topic: Reviving a '73 750 (Read 11041 times)

seanbarney41 · « **Reply #50 on:** August 10, 2020, 07:53:37 PM »

If you are gonna put cheap, non oem parts back in there, you should have never tore it down. Expert mechanics often fail at improving these, how are you gonna fix anything using cheap gaskets? Give the thing a chance.

gpzkat · « **Reply #51 on:** August 10, 2020, 08:44:01 PM »

Yeah that's valid, but OEM didn't even do the job, except possibly for the pucks but who knows, this engine was coated with oil. I get it, do it right or don't do it at all. I'm mainly grumpy because I was an idiot for buying that set, and having to fork over more and wonder about all the other stuff like guides, grinding etc. On a non-running unknown quantity I got lucky so far given what I've seen inside, so I can take some comfort in that, could have been a disaster in there.

Quote from: seanbarney41 on August 10, 2020, 07:53:37 PM

If you are gonna put cheap, non oem parts back in there, you should have never tore it down. Expert mechanics often fail at improving these, how are you gonna fix anything using cheap gaskets? Give the thing a chance.

seanbarney41 · « **Reply #52 on:** August 11, 2020, 03:18:02 PM »

oem did do the job...I can pretty much guarantee at least one p.o. didn't. It could have been a disaster in there, but it wasn't, and rarely ever is with these. Did you even start it up to see how bad the leaks were? One leaking valve inspection cap can make a huge mess in less than 5000 miles if no one ever cleans the oil off.

gpzkat · « **Reply #53 on:** August 11, 2020, 03:46:55 PM »

No it was a long way from being able to run,let alone ride and check the gears etc. The PO had opened up the valve clearances to their max and the cam chain was so loose I could hear it click when turning over, among other things, so I stopped there and decided to open it up. It's no big deal just the mistake of buying cheap gaskets is a lesson learned and I will get the good stuff and it will be fine.

Quote from: seanbarney41 on August 11, 2020, 03:18:02 PM

oem did do the job...I can pretty much guarantee at least one p.o. didn't. It could have been a disaster in there, but it wasn't, and rarely ever is with these. Did you even start it up to see how bad the leaks were? One leaking valve inspection cap can make a huge mess in less than 5000 miles if no one ever cleans the oil off.

Stev-o · « **Reply #54 on:** August 11, 2020, 04:10:50 PM »

I use copper spray on my Kawasaki two-stoke triples, they have metal head gaskets.
Never on the SOHC and +1 use good parts including gaskets.

gpzkat · « **Reply #55 on:** September 02, 2020, 05:51:38 PM »

I have been making progress on the CB but with 4 bikes it's become sporadic. My GS1100E turbo is getting jetted and it has a charging issue, not unusual. Gave them a spare reg/rec to try but not a long term fix. Then there's the 94 XT350 I got for a learner for my son to do fire roads on, and it needed tires, brakes, and some fiddling, just waiting on chain and sprocket to finish it. The CB is getting some frame stuff powder coated, mostly ready to put back together but need to start on cosmetics soon.

gpzkat · « **Reply #56 on:** September 13, 2020, 07:20:39 PM »

Got some frame stuff back from the powder coating, nice to have a neighbor that runs a big shop. I'm just going to paint the frame, didn't want to take too much advantage of his generosity. I also painted the headlight bucket and the warning lights, and the instrument housings. I ordered new face plates as mine were warped and faded, should come up quite nicely.

The GS1100E turbo is back from the tuner so I'm finishing a couple things on that, should be an interesting first ride with 185 RWHP on tap and 102 lb/ft of torque.

Stev-o · « **Reply #57 on:** September 16, 2020, 01:29:23 PM »

Nothin' like fresh powder!

gpzkat · « **Reply #58 on:** September 19, 2020, 09:14:08 AM »

Yeah it is so nice, it is inspiring me to get the frame done, will work on it today, finally the humidity has gone down so I can spray without it blushing.

Engine ready for reassembly and got new repro face plates for the gauges, really nice and a reasonable price shipped from the UK.

Quote from: Stev-o on September 16, 2020, 01:29:23 PM

Nothin' like fresh powder!

gpzkat · « **Reply #59 on:** September 25, 2020, 05:26:07 PM »

Got one of the gauges done, pretty good, I painted/baked the housing and put on a new face plate due to fading/warpage. Also have new chrome bucket on the back. Tedious work but rewarding. I used fluorescent orange on the needle tip and flat white on the main part, then dabbed some silver on the center ring. It's a lot better but not show quality. I haven't cleaned the outside glass well, so there are some specks, but the inside is good.

gpzkat · « **Reply #60 on:** September 30, 2020, 02:37:51 PM »

I have painted the frame and finished the gauges. I will do a cut/polish on the painted housings. They aren't perfect because I bunged up the crimp ring a bit on one, but it's not going to be a show bike, just a real nice rider. It's a funny perspective on the frame in below picture, my brother said "man those frame rails are wide". I used Rustoleum epoxy appliance paint, my new value favorite and 1/2 price of VHT, did the headlight shell with it too, and they both look great.

wolf550 · « **Reply #61 on:** September 30, 2020, 02:48:54 PM »

I work over in the M.V. by Saddleback CC
I think I might hear that GS sometimes! LOL
let me know when you are doing some testing on that TURBO so I can do a drive by! would love to hear that spool up!

gpzkat · « **Reply #62 on:** October 04, 2020, 09:18:57 PM »

I have lapped the valves, most looked pretty good to start with but I saw some black pits that I worked out with coarse then fine compound on a couple of the exhaust seats. Used fine on the rest. It 'seems' good to me but I have never done this before so I don't know. I will try filling the chamber with gasoline to see if they leak. Here is a pic, if anyone has advice I'd appreciate it. The valves and seats looked really good to start with so I hope lapping is sufficient. I know a 3 angle complete top end redo is best but I will be happy with it as long as it runs well and doesn't smoke. The valve guides seem good, there is no play when dry, and no discernable difference when I apply some oil. I have new oil seals and rings, quality gaskets and am putting in APE studs. I have done a top end on Kawi GPz1100 very successfully a few years ago and this bike seems as good or better.

gpzkat · « **Reply #63 on:** October 21, 2020, 11:53:57 AM »

Edit: Did some better searching on keywords and found a thread that explains this issue, will check out the suggested fixes and see which works best for me.

I am working on the steering stem and finding that the bearing situation is a bit odd. The PO put in tapered bearings and when reassembling there is too much height to make the fork ears fit right. I didn't look carefully when taking it apart but have all parts and they don't add up. If anyone can help me with what to do I appreciate it, I don't want to screw this up.

Here is what's going on. Pic one shows a spacer (?) that prevents the race from going in far enough to assemble as needed for the proper fitting.

Pic 2 shows that due to this spacer the bearing sits proud of the top - I haven't put it in completely, as I did and then removed it.

Pic 3 shows that the threaded retainer should sit in order to have proper fit for the fork ears.

Pic 4 shows approximately the extra height that I get with the setup as it is.

So I'm thinking this spacer needs to be extracted somehow. It doesn't look like it's part of the original ball bearing setup, per the diagrams I've seen on Partzilla, so maybe it's a PO mistake?

Measuring shows the race plus bearing plus dust seal is 16mm, and that's equal to the height of the space from the ridge below the spacer to the top of the headstock, so it seems like this piece is not correct.

gpzkat · « **Reply #64 on:** October 25, 2020, 09:03:31 AM »

I really don't like that top bearing sticking up and messing up fork ears, going to do some more thinking about what I can do about it.

In the meantime, other fish to fry. I assembled the the top end yesterday. It was super easy to get the rings in using strips from a plastic bleach bottle and hose clamps. I 'burnished' the APE studs like the Cycle-X site recommends, 6x on the torque in increments is a lot of screwing. Ready for the valve cover today and install into the frame.

PeWe · « **Reply #65 on:** October 25, 2020, 09:47:09 AM »

Your bearing race is not fully in.
You see the edge inside and it sit angled. Take it out, make sure surfaces have no scars, if it has, file it or use a sanding grinder.

This thread has lots of info about those bearings.
Read it all and you'll know.

http://forums.sohc4.net/index.php/topic,1516.0.html

gpzkat · « **Reply #66 on:** October 25, 2020, 11:17:59 AM »

I had it in earlier, this was just for pic. When in completely it wouldn't let the retainer screw down far enough.

Been reading the threads and see that many just lived with it and either modified the retainer or added spacers. Still reading though, maybe I'll find a fix I am satisfied with as I don't think these are the right way. Thanks!

Quote from: PeWe on October 25, 2020, 09:47:09 AM

Your bearing race is not fully in.
You see the edge inside and it sit angled. Take it out, make sure surfaces have no scars, if it has, file it or use a sanding grinder.

This thread has lots of info about those bearings.
Read it all and you'll know.

http://forums.sohc4.net/index.php/topic,1516.0.html

PeWe · « **Reply #67 on:** October 25, 2020, 01:32:08 PM »

My K2 build got roller bearings and stock headlight holders.
It was 2-3mm at top which I covered by a rubber washer.
Made my own by vulc tape.

Ears sits fine.

http://forums.sohc4.net/index.php?topic=168243.msg2042114.msg#2042114

The bearings shown on page above.

Took a photo now about the small gap covered by the additional rubber.

gpzkat · « **Reply #68 on:** October 26, 2020, 06:03:35 PM »

Time to install the frame

The Harbor Freight 1 ton hoist has served me well for the $50.

gpzkat · « **Reply #69 on:** November 07, 2020, 05:03:50 PM »

Se got legs! Took my time with the swingarm, put in the bronze bushings and had to replace the collar with a NOS replacement as mine was shot. Read up on all the tips on this forum. Next comes wiring.

gpzkat · « **Reply #70 on:** November 08, 2020, 04:47:41 PM »

Brake work today, new Honda MC innards and brake caliper seal, new pads, and some spit and polish. This for me is the fun part.

gpzkat · « **Reply #71 on:** November 14, 2020, 09:01:41 PM »

Put on the seat and a side cover, just fooling around between assembly. My friend has a couple of blue side covers but an orange tank and I may borrow his while I redo mine as he's far behind on his.

I like the blue even though it's not a '73 color. It' not a show bike so I'll think it over. Too many orange but I like. Bacchus olive is 2nd choice of the '73 and the brown a distant 3rd. But the reds and blues are my favorite.

PeWe · « **Reply #72 on:** November 16, 2020, 10:01:45 AM »

You have seen the colors on Yamiya750.com?

Freedom Green Metallic another good looking green-bluish color for 1974.

It would be fine with 3-4 sets!

Old Scrambler · « **Reply #73 on:** November 16, 2020, 02:00:46 PM »

Nice early K3.......I'm partial to the Olive Green

Check your tires for rotation arrows.........

gpzkat · « **Reply #74 on:** November 16, 2020, 06:44:29 PM »

Yeah I told the shop to mount right way and they messed up. I think it's for rain dispersal and I don't ride in rain here in LA, I just drive my car.

Quote from: Old Scrambler on November 16, 2020, 02:00:46 PM

Nice early K3.......I'm partial to the Olive Green

Check your tires for rotation arrows.........

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Author Topic: Reviving a '73 750 (Read 11041 times)