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Saving a 1980 750 twin.

  • Street Fighter LTD
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13 Nov 2018 14:14 #793766 by Street Fighter LTD
Replied by Street Fighter LTD on topic Saving a 1980 750 twin.
Nice job,
If you do decide to look for new bolts I woulld call ARP bolts
They are the best I know of
Dave


Original owner 78 1000 LTD
Mr Turbo Race Kit, MTC 1075 Turbo pistons by PitStop Performance , Falicon Ultra Lite Super Crank, APE everything. Les Holt @ PDM's Billet Goodies . Frame by Chuck Kurzawa @ Logghe Chassis . Deep sump 5qt oil pan. RIP Bill Hahn

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  • DoctoRot
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13 Nov 2018 21:59 #793771 by DoctoRot
Replied by DoctoRot on topic Saving a 1980 750 twin.
I found a set of connecting rod bolts for a Mitsubishi Evo that ARP sells that i believe would work, however the guys at Falicon, told me it wasnt worth the trouble unless the bolts I have had been torqued many times. I used a spare set of bolts for torquing when I was measuring the journals for new bearings.

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  • DoctoRot
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11 Mar 2019 00:44 - 11 Mar 2019 00:45 #800136 by DoctoRot
Replied by DoctoRot on topic Saving a 1980 750 twin.
Finally some updates here. I took a little break and saved up for some goodies. RS34 carbs all the way from Germany, and a custom grind from Web camshafts!

I ended up decking the head .050". that , combined with the higher compression Venolia pistons, puts static compression at 10.6/1



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Last edit: 11 Mar 2019 00:45 by DoctoRot.

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11 Mar 2019 07:55 #800162 by 531blackbanshee
Replied by 531blackbanshee on topic Saving a 1980 750 twin.
WOW!

leon

skiatook,oklahoma 1980 z1r,1978 kz 1000 z1r x 3,
1976 kz 900 x 3
i make what i can,and save the rest!

billybiltit.blogspot.com/

www.kzrider.com/forum/5-chassis/325862-triple-tree-custom-work

kzrider.com/forum/5-chassis/294594-frame-bracing?limitstart=0

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  • DoctoRot
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17 Mar 2019 01:26 - 17 Mar 2019 01:27 #800468 by DoctoRot
Replied by DoctoRot on topic Saving a 1980 750 twin.
I slotted a second set of cam sprockets properly on the mill because my original job that i did with the file was pretty rough and i wasn't happy with it. I also finished machining the starter clutch. I thought it would be tougher and need to be ground but a carbide cut it just fine.

I have been screwing around with my tool setup to time these cams. A lot of trial and error to get make a feeler that can touch the tappet AND not get in the way of the cam AND go that deep into the head, finally got it right only to break my dial indicator! I then borrowed a friends dial indicator only to break my tool holder! I was getting super irritated with my cheapy Chinese dial indicator setup anyway, I just couldn't get consistent numbers with it here for some reason. I did what any sensible human does when they get pissed at their tools and splurged. I got a nice Mitutoyo drop dial and a NOGA magnetic base. Ive never had so much trouble timing a cam.

TLDR; I don't want a pickle, i just want to ride my motor-sickle



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Last edit: 17 Mar 2019 01:27 by DoctoRot.

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18 Mar 2019 14:06 #800587 by 531blackbanshee
Replied by 531blackbanshee on topic Saving a 1980 750 twin.
i love my NOGA base!

leon

skiatook,oklahoma 1980 z1r,1978 kz 1000 z1r x 3,
1976 kz 900 x 3
i make what i can,and save the rest!

billybiltit.blogspot.com/

www.kzrider.com/forum/5-chassis/325862-triple-tree-custom-work

kzrider.com/forum/5-chassis/294594-frame-bracing?limitstart=0
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  • Scirocco
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18 Mar 2019 14:41 #800590 by Scirocco
Replied by Scirocco on topic Saving a 1980 750 twin.
DoctoRot wrote:
I have been screwing around with my tool setup to time these cams. A lot of trial and error to get make a feeler that can touch the tappet AND not get in the way of the cam AND go that deep into the head, finally got it right only to break my dial indicator! I then borrowed a friends dial indicator only to break my tool holder! I was getting super irritated with my cheapy Chinese dial indicator setup anyway, I just couldn't get consistent numbers with it here for some reason. I did what any sensible human does when they get pissed at their tools and splurged. I got a nice Mitutoyo drop dial and a NOGA magnetic base. Ive never had so much trouble timing a cam.

I have the luck to get a good set of analog and digital dial indicator too.
Got a set of Mitutoyo drop dials for a tip that have must be renovation for the ISO 9001 certification (European Quality Standard) out of my Company workplace.

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  • DoctoRot
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21 Mar 2019 03:10 - 21 Mar 2019 03:11 #800766 by DoctoRot
Replied by DoctoRot on topic Saving a 1980 750 twin.
The new tool setup is soooo much better, I can zero the dial in 5 seconds as opposed to 5 minutes. The adjustability and rigidity is much better as well. However, I am still getting a small bit of variation on the degrees.

The indicated degrees will fluctuate +/- half a degree on my target, despite the dial coming back to zero every time. This means the lobe center can be as much as 1 degree off target. I have tried many things to try and tighten it up and nothing has removed this. I checked to see if the feeler was dragging at all and it clears everything completely. I called Web Camshafts up and they thought it could be variations in the cam chain or the OEM style spring cam chain tensioner. The cam chain is brand new, so im scratching my head. Right now the cams are very close to where they need to be, but they're not perfect.

After I got the cams timed I clayed the pistons to make sure there weren't any problems. You can see in my tool setup I cut off most of a spare cam cover so i could access the cam sprocket bolts without moving my tool setup. this made dialing in the timing much easier.

Any suggestions on what I could look at to remove the small degree variations? I'm stumped.

Last edit: 21 Mar 2019 03:11 by DoctoRot.

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21 Mar 2019 18:23 #800806 by Nebr_Rex
Replied by Nebr_Rex on topic Saving a 1980 750 twin.
Don't take this the wrong way. Operator error, you need two things to correct this.
A longer wrench to turn the engine over and a bigger degree wheel. A tight engine is
hard to turn over and thus harder to control. With a longer wrench it will be easier to
finesse that last .001. A bigger degree wheel make it easier to differentiate that last degree.


.

2002 ZRX1200R
81 GPz1100
79 KZ1000st daily ride
79 KZ1000mk2 prodject
78 KZ650sr
78 KZ650b
81 KZ750e
80 KZ750ltd
77 KZ400/440 cafe project
76 KZ400/440 Fuel Injected

www.dotheton.com/forum/index.php?topic=39120.0


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21 Mar 2019 19:20 #800810 by Dr. Gamma
Replied by Dr. Gamma on topic Saving a 1980 750 twin.

Nebr_Rex wrote: Don't take this the wrong way. Operator error, you need two things to correct this.
A longer wrench to turn the engine over and a bigger degree wheel. A tight engine is
hard to turn over and thus harder to control. With a longer wrench it will be easier to
finesse that last .001. A bigger degree wheel make it easier to differentiate that last degree.


.


This degree wheel works great for old blind people like me!!!!! Its from Comp Cams.

There is about 1/8 of an inch between each degree on this wheel. I love working with a degree wheel this big!!!


1972 H2 750 Cafe Racer built in 1974.
1976 KH400 Production Road Racer.
1979 Kz1000 MK. II Old AMA/WERA Superbike.
1986 RG500G 2 stroke terror.
1986 GSXR750RG The one with the clutch that rattles!

Up in the hills near Prescott, Az.
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  • bluej58
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21 Mar 2019 19:30 #800812 by bluej58
Replied by bluej58 on topic Saving a 1980 750 twin.
I asked my friend a retired mold maker and he said " A dial indicator measures distance, not degrees"
I may get a better answer from him in the morning.

78 KZ1000 A2A

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  • DoctoRot
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22 Mar 2019 00:53 #800815 by DoctoRot
Replied by DoctoRot on topic Saving a 1980 750 twin.

bluej58 wrote: I asked my friend a retired mold maker and he said " A dial indicator measures distance, not degrees"
I may get a better answer from him in the morning.


The dial indicator measures the lift of the cam. when it reaches .050" you look at the degree wheel and note the degree that the valve "opened" at so you can determine the lobe center.

Thanks for the tips guys. I will give that a try. That comp cam degree wheel is $200! it looks nice, but damn... $200 I'll figure something out.

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