Author Topic: 1974 cb750 fun "Spruce Goose" (STEP 2: frame/suspension)  (Read 28444 times)

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Offline calj737

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Re: 1974 cb750 fun "Spruce Goose" (STEP 2: frame/suspension)
« Reply #125 on: February 03, 2016, 04:09:41 PM »
Dude put a towel under that beauty!  :o
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Offline mashfu

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Re: 1974 cb750 fun "Spruce Goose" (STEP 2: frame/suspension)
« Reply #126 on: February 03, 2016, 04:19:12 PM »
But how would i be able to torque hahahaha just enough space between the wood! And noob mistake i torqued it down and remembered i forgot the seal on the crank... That was fun! But all torqued down and ready for pistons/jugs  ;D

Offline mashfu

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Re: 1974 cb750 fun "Spruce Goose" (STEP 2: frame/suspension)
« Reply #127 on: February 05, 2016, 02:58:29 PM »
As i buttoned up the clutch, i wanted to see if i could still rotate the crank; however, as i tighten the clutch cover it becomes increasingly harder to rotate. Is this normal or did i install the clutch incorrectly? If this is not normal, i will probably get rid of one of the friction plates as described in Mark's book to make a pseudo k0/k1 clutch.

*edit saw some videos that do rotate with a socket to the rotor or points, so there is definitely some resistance but at one point it would not move at all. Ive gotten it to move more freely after bringing the clutch adjustment bolt in away from the engine. Either that or removing the clutch cover a few times and slowly torquing it down.*
« Last Edit: February 05, 2016, 04:13:40 PM by mashfu »

Offline mashfu

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Re: 1974 cb750 fun "Spruce Goose" (STEP 2: frame/suspension)
« Reply #128 on: February 05, 2016, 08:56:29 PM »
Believe i found what the problem is (center clutch) i believe i saw a post here before, but it totally slipped my mind and at the time i had no idea what the thread was even talking about. While ordering a new clutch, i ended up getting a 78's clutch but forgot that it is slightly longer. The problem is arising from the center bottoming out on the outer which then rubs against the clutch cover. Ive sanded a bit off of the washer that goes between the center and outer but still feels there is some catching. Since i already took some material off the washer, i will now take some off of the center that is touching the cover. Hopefully this works or i can just get an appropriate center.


Offline mashfu

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Re: 1974 cb750 fun "Spruce Goose" (STEP 2: frame/suspension)
« Reply #129 on: February 05, 2016, 10:36:57 PM »
Problem solved... such a simple solution to something i thought was much worse. Ended up being the small dimple (for a screw) on the back of the clutch cover that protruded out and interfered with the clutch. Took a few mm off the top and now the crank rotates just how i want it to! Stole a picture off google to show what i am talking about. WOOOOO
I really want to hit myself in the face now... found the thread i was looking for after i fix it... FIGURES!
« Last Edit: February 05, 2016, 10:42:08 PM by mashfu »

Offline mashfu

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Re: 1974 cb750 fun "Spruce Goose" (STEP 2: frame/suspension)
« Reply #130 on: February 07, 2016, 04:41:54 PM »
Got myself a multi-meter and tested the resistance across the field and stator coil. Came up with 7.0-7.3 ohm across field and stator had about .2-.5 ohm across all three. Only reason the readings range so much is when i checked the resistance between the probes, the resistance showed between .2 and .5, i got a consistent .7 ohm on all combinations between the three yellow stator wires and a consistent 7.5 ohm between the two field wires. Seems everything is in usable limits.

Offline mashfu

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Re: 1974 cb750 fun "Spruce Goose" (STEP 2: frame/suspension)
« Reply #131 on: February 09, 2016, 05:40:09 PM »
The joy of simple green!

Offline SOHC4 Cafe Racer Fan

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Re: 1974 cb750 fun "Spruce Goose" (STEP 2: frame/suspension)
« Reply #132 on: February 09, 2016, 06:38:49 PM »
Did you do a HOT soak, wire brush, ultrasound or combination?
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Offline mashfu

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Re: 1974 cb750 fun "Spruce Goose" (STEP 2: frame/suspension)
« Reply #133 on: February 09, 2016, 08:00:46 PM »
Did the whole hot soak and wire brush on the f head that originally planned on using but got some dark oxidation which should be easy to clean up. Since then i got another head and thought i might try cleaning it differently so i just used simple green and a nylon brush let it soak for about 5 minutes and pressure hosed it off. Ultrasonic would definitely be nice for the inside gunk but ill try to pick all the large clumps before that

Offline SOHC4 Cafe Racer Fan

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Re: 1974 cb750 fun "Spruce Goose" (STEP 2: frame/suspension)
« Reply #134 on: February 09, 2016, 08:08:39 PM »
It came out nice.  I've done the hot soak with Simple Green but it still required lots of wire brush work.
1975 CB550K1 "Blue" Stockish Restomod (http://forums.sohc4.net/index.php?topic=135005.0)
1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2008 Triumph Thruxton (http://forums.sohc4.net/index.php/topic,190956.0.html)
2014 MV Agusta Brutale Dragster 800
2015 Yamaha FZ-09 (http://forums.sohc4.net/index.php/topic,186861.0.html)

"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

Sold/Emeritus
1973 CB750K2 "Bionic Mongrel" (http://forums.sohc4.net/index.php?topic=132734.0) - Sold
1977 CB750K7 "Nine Lives" Restomod (http://forums.sohc4.net/index.php?topic=50490.0) - Sold
2005 RVT1000RR RC51-SP2 "El Diablo" - Sold
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold

Offline mashfu

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Re: 1974 cb750 fun "Spruce Goose" (STEP 2: frame/suspension)
« Reply #135 on: February 09, 2016, 08:48:51 PM »
Thank you, ya the caked on gunk just melts away with the wire sooooo satisfying!

Offline mashfu

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Re: 1974 cb750 fun "Spruce Goose" (STEP 2: frame/suspension)
« Reply #136 on: February 10, 2016, 12:30:10 AM »
Couldn't stand it any longer had to see what im getting myself into. Haven't gotten the stem conversion just yet but can still do a quick mock up!

Offline mashfu

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Re: 1974 cb750 fun "Spruce Goose" (STEP 2: frame/suspension)
« Reply #137 on: February 10, 2016, 11:17:33 PM »
Was having the hardest time removing a few tappet covers so did some searching and ended up trying two suggestions first filing the sides of the hex down to a smaller size (no success) next was chisel. They came off like butter after a few whacks! One more to go, think ill save it for when people aren't sleeping  ;D

Offline mashfu

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Re: 1974 cb750 fun "Spruce Goose" (STEP 2: frame/suspension)
« Reply #138 on: February 12, 2016, 06:43:29 PM »
Lapped the valves today, really glad i got hondaman's book! Used the k valves to test and got the seal area to be about 1mm-1.5mm on all of them. Only thing that i could see that might cause some concern is the margin. Will probably compare these valves to the f valves and see which ones have been worn down less. After that is done i will be doing a leak test to make sure everything is nice and tight. Also began a test on the spare jugs that i have to see how they might look with black wrinkle, will have some pictures up later tonight  ;D

Offline redwillis1978

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Re: 1974 cb750 fun "Spruce Goose" (STEP 2: frame/suspension)
« Reply #139 on: February 12, 2016, 06:51:44 PM »

Couldn't stand it any longer had to see what im getting myself into. Haven't gotten the stem conversion just yet but can still do a quick mock up!
You will want to mock up your tank choice ASAP and see how much modification it is going to take at the front.

Offline mashfu

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Re: 1974 cb750 fun "Spruce Goose" (STEP 2: frame/suspension)
« Reply #140 on: February 12, 2016, 09:47:58 PM »
Not sure if this is up to standard but i got the pitch to change when the valve hits the seat, after lapping for a few minutes. Definitely needs some touch up to the chambers themselves think i will do a lighter touch up than i did to the f head to get the carbon off.
Comparison of k and f respectively.

Offline mashfu

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Re: 1974 cb750 fun "Spruce Goose" (STEP 2: frame/suspension)
« Reply #141 on: February 12, 2016, 11:47:26 PM »

Couldn't stand it any longer had to see what im getting myself into. Haven't gotten the stem conversion just yet but can still do a quick mock up!
You will want to mock up your tank choice ASAP and see how much modification it is going to take at the front.
That completely skipped my mind, I'll put them all on again soon to see if there is anything interfering

Offline mashfu

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Re: 1974 cb750 fun "Spruce Goose" (STEP 2: frame/suspension)
« Reply #142 on: February 13, 2016, 01:24:14 PM »
Doing it right this time! Taped up, protected and finer grit

Offline mashfu

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Re: 1974 cb750 fun "Spruce Goose" (STEP 2: frame/suspension)
« Reply #143 on: February 15, 2016, 10:31:15 PM »
A few more passes with acetone and i can start painting, painted the other jugs i have without any prep just to test the waters. Came out horrible but i expected worse hahaha! Dirt, oil and other particles give it character~  >:(

Offline mashfu

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Re: 1974 cb750 fun "Spruce Goose" (STEP 2: frame/suspension)
« Reply #144 on: February 16, 2016, 07:01:40 AM »
Bottom side first, gonna let it sit for a bit then get the top

Offline mashfu

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Re: 1974 cb750 fun "Spruce Goose" (STEP 2: frame/suspension)
« Reply #145 on: February 16, 2016, 03:59:48 PM »
Sat in the sun for a few hours... California weather  ;D there are a few flat spots on the top fin but since the head will be blocking it, i can't complain! This will be the only piece to get some paint everything else is just going to get some extra love from the scotchbrite!

Offline mashfu

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Re: 1974 cb750 fun "Spruce Goose" (STEP 2: frame/suspension)
« Reply #146 on: February 20, 2016, 06:59:47 PM »
Finally have a day off! Cut some pvc and started to insert pistons 2&3. Put some marvel oil on the rings and coated the jugs with oil aswell. 2 more shims for 1&4 and that should do it!

Offline mashfu

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Re: 1974 cb750 fun "Spruce Goose" (STEP 2: frame/suspension)
« Reply #147 on: February 20, 2016, 07:51:55 PM »
Success!  And then the power went out its a sign! Too much awesomeness

Offline edwardmorris

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Re: 1974 cb750 fun "Spruce Goose" (STEP 2: frame/suspension)
« Reply #148 on: February 20, 2016, 08:21:57 PM »
Can't tell from the pix but I really hope there were two o-rings of proper thickness on the rear central two studs. Good progress!

Offline mashfu

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Re: 1974 cb750 fun "Spruce Goose" (STEP 2: frame/suspension)
« Reply #149 on: February 20, 2016, 08:40:03 PM »
Quadruple checked!