Author Topic: 78 750 F3 Rust Bucket competed  (Read 1667 times)

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Offline Graydude

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78 750 F3 Rust Bucket competed
« on: December 12, 2011, 11:35:49 am »
I guess I'm about as done as I'm gonna be.  No more major items to complete other than pulling the engine at some point to see why my compression is 90 to 120 across the cylinders and why she smokes like a diesel.  Other than that I am very pleased with the overall project.  Five months and an undisclosed fortune were invested.  I can tell you I never would have started this project without this board and it's members as resources.  You guys are the best and I hope I can give back with my experiences.  You can check out the progress here during my rebuild here by clicking the link on my signature line at the bottom of this post.  I would welcome anyone chiming in after hearing the bike run MOV02836.MPG

I thought some before and after pictures would be fun.  Remember I received the bike from my son in May after it sat outside in Seattle for 14 years.  It does have a new California plate "BITCN 78" on it's way!

























Thanks again to all the parts donors.  Let me know what you think!

Todd/Graydude


Offline jaguar

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Re: 78 750 F3 Rust Bucket competed
« Reply #1 on: December 12, 2011, 12:02:06 pm »
Thats one good looking bike!

Offline theofam

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Re: 78 750 F3 Rust Bucket competed
« Reply #2 on: December 12, 2011, 07:30:08 pm »
Nice work!  I hope mine looks half as cool when done.

Offline Toxic

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Re: 78 750 F3 Rust Bucket competed
« Reply #3 on: December 13, 2011, 04:03:22 am »
Nice transformation.

What smoke?  You didn't show any smoke on the vid.  Could be assembly lube burning off or just condensation due to the cold temp.
What color is the smoke? What does it smell like.
How many miles have you put on it?

I would be more concerned with the oil light not working at this point.  Do you have an oil pressure gauge as a substitute?  Have you verified that the top end is getting oil?

I wouldn't be concerned about your comp. numbers on a freshly rebuilt motor either. 

Offline jaguar

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Re: 78 750 F3 Rust Bucket competed
« Reply #4 on: December 13, 2011, 05:43:27 am »
You should stop over at bike of the month....

Offline MCRider

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Re: 78 750 F3 Rust Bucket competed
« Reply #5 on: December 13, 2011, 06:50:27 am »
14 years! isn't it amazing that happens?  Anyway, nice pulling one back from the brink.

You mention rings and pistons. Did you do head work too? The 78Fs are notorious for needing valve guides at around 20,000 miles or more. Could be the cause of your smoke and a little excess sewing machine noise.
« Last Edit: December 13, 2011, 06:55:23 am by MCRider »
Ride Safe:
Ron
1988 NT650 HawkGT;  1978 CB400 Hawk;  1975 CB750F -Free Bird; 1968 CB77 Super Hawk -Ticker;  Phaedrus 1972 CB750K2- Build Thread
"Sometimes the light's all shining on me, other times I can barely see, lately it appears to me, what a long, strange trip its been."

Offline Steve_K

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Re: 78 750 F3 Rust Bucket competed
« Reply #6 on: December 13, 2011, 07:31:28 am »
+1  very bice bike and the paint on the tank looks great
Steve
Steve_K

76 CB 550, 73CB750, 86 GSX-R750, 16 Slingshot
Old rides:305 Honda, CL350, 74 CB550
 05 SV1000S, 88 CBR600,92 VFR, 88 Hawk GT, 96 Ducati 900SS, 98 Kaw ZX6R, SV650

Offline Graydude

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Re: 78 750 F3 Rust Bucket competed
« Reply #7 on: December 13, 2011, 07:43:58 am »
Nice transformation.

What smoke?  You didn't show any smoke on the vid.  Could be assembly lube burning off or just condensation due to the cold temp.
What color is the smoke? What does it smell like.
How many miles have you put on it?

I would be more concerned with the oil light not working at this point.  Do you have an oil pressure gauge as a substitute?  Have you verified that the top end is getting oil?

I wouldn't be concerned about your comp. numbers on a freshly rebuilt motor either.

Good questions Toxic.  I replaced the oil sender and verified continuity in the wire and checked the dash bulb but I still cannot get the light to come on.  I've not verified oil pressure with a gauge but that is a good next option.  The smoke is definitely oil smoke.  I have a few hundred miles on her and the smoke only comes on when she is good and warmed up.  At a traffic light I bring my own fog layer.  Cars kinda inch away from me like I have the plague.  The neutral light is also evasive.  I checked the sender and even got it to work for a couple of weeks but then that shaft moved again, just a small amount, and now the light does not work in neutral.  I guess it will always be something with a 35 year old bike.

Yes, I did the top end with new guides and valve seals and had the whole head serviced. The shop was not a motorcycle focused shop.  My suspensions lie in the head.  The compression does not go up when put a tablespoon of oil into each cylinder.
« Last Edit: December 13, 2011, 07:48:39 am by Graydude »

Offline MCRider

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Re: 78 750 F3 Rust Bucket competed
« Reply #8 on: December 13, 2011, 07:58:58 am »
Hmmm. All you can do is take it apart and check things.
Ride Safe:
Ron
1988 NT650 HawkGT;  1978 CB400 Hawk;  1975 CB750F -Free Bird; 1968 CB77 Super Hawk -Ticker;  Phaedrus 1972 CB750K2- Build Thread
"Sometimes the light's all shining on me, other times I can barely see, lately it appears to me, what a long, strange trip its been."