Author Topic: Salt Racer CB 750 OZ style  (Read 169693 times)

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Offline johno

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Re: Salt Racer CB 750 OZ style
« Reply #1175 on: March 31, 2015, 03:12:49 AM »


Well check the plugs , like number two again  :o

No need for leakdown test.   Hope your legs are better than my pistons Bear ;D
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Offline johno

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Re: Salt Racer CB 750 OZ style
« Reply #1176 on: March 31, 2015, 03:42:10 AM »


Hmmmmmm number two again, action replay :o
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Offline johno

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Re: Salt Racer CB 750 OZ style
« Reply #1177 on: March 31, 2015, 03:45:01 AM »


Wrong, these are not the old pictures from last time ;)
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Offline johno

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Re: Salt Racer CB 750 OZ style
« Reply #1178 on: March 31, 2015, 03:48:37 AM »


WTF  :o :o :o >:(
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Offline johno

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Re: Salt Racer CB 750 OZ style
« Reply #1179 on: March 31, 2015, 03:51:01 AM »


Hmmmm Mikey , lets look at the head ????????
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Offline johno

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Re: Salt Racer CB 750 OZ style
« Reply #1180 on: March 31, 2015, 04:13:19 AM »


FCUK FCUK FCUK
After I calm down I think between Mike and Jim we could salvage the head, its just too good to not try., its not into the gasket area, the MLS seemed to protect that area compared to the composites. the damage is not close to the seats , Jim is a ledgend, nice bloke, good welder, thorough gentleman. I've seen some of his work that Jerry had done so after Mike makes comment I,m hoping he will let me ship it to him for a play and he can pass onto Jim.        would be the only thing that will cheer me up.

So turned out like a coroners report .

You folks are looking at the same #$%* as I am, lets look at the facts.
Identical problem on number two, absolutely identical damage and cylinder, hmmmmmm
I changed the type of piston, changed the conrod, changed the carbies, changed the barrels, the only thing left is the head and the ignition.  I personnally checked the depth of the valves last time and again when checking the piston to head , piston to valve and anything else I could thing of , all the valve positions were identical.  So in my mind it aint the exhaust or head  and last time I blamed the ignition as it was programmed wrong from the supplier and I didnt check it. Detonated the fcuk out of number two. This time I got the correct programme from the supplier and installed it and checked it.

Gunna have to be a case of 3rd time lucky.   If you were a betting man what do you reckon I will fcuken smash with a hammer just to make sure its not 3 times in a row. anyone can make a mistake once, slow learners can twice, only dickheads do it 3 times and Im not planning to be a dickhead  >:(

Anway if you can change my mind feel free , I need cheering  up. ???
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Offline Old Scrambler

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Re: Salt Racer CB 750 OZ style
« Reply #1181 on: March 31, 2015, 07:44:08 AM »
'Buggers'.................especially about the head.

From my experiences, properly metered modern race-gas and cold-range plugs tend to run very clean. On my motors it takes numerous runs and/or very wrong jets to show deposits on the electrodes. Your motor may need different jetting on #2-3 versus #1-4.

Theory..........you may be running rich and suddenly going very lean when above 8000 rpm...........possibly caused by lack of air-flow TO the carbs at high-speed. That condition will not show on a static dyno-test. 
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Offline Jerry Rxman Griffin aka MuthaF'er

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Re: Salt Racer CB 750 OZ style
« Reply #1182 on: March 31, 2015, 10:47:13 AM »
Son of a #$%*!

You sure have potential though FWIW....

Are you checking exhaust temps?
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Offline dragracer

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Re: Salt Racer CB 750 OZ style
« Reply #1183 on: March 31, 2015, 12:01:26 PM »
Wow. I really did think I was looking at last years pictures.

Offline Retro Rocket

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Re: Salt Racer CB 750 OZ style
« Reply #1184 on: March 31, 2015, 03:59:03 PM »
#$%* Johno, killed any China men lately... >:(
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
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Offline bear

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Re: Salt Racer CB 750 OZ style
« Reply #1185 on: March 31, 2015, 04:16:04 PM »
WELL................ >:( >:(FCUK MY BROWN DOG SPOT >:(

My opinion.......................throw that fancy ignition to the #$%*house.
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Offline dragracer

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Re: Salt Racer CB 750 OZ style
« Reply #1186 on: March 31, 2015, 05:39:20 PM »
WELL................ >:( >:(FCUK MY BROWN DOG SPOT >:(

My opinion.......................throw that fancy ignition to the #$%*house.
I'd have to agree with that statement. I don't think it was all a lean fueling issue. Detonation does that mostly. We run a lot of nitrous over here and see that in missed timing tune-ups.

Offline MRieck

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Re: Salt Racer CB 750 OZ style
« Reply #1187 on: March 31, 2015, 05:49:35 PM »
WELL................ >:( >:(FCUK MY BROWN DOG SPOT >:(

My opinion.......................throw that fancy ignition to the #$%*house.
I'd have to agree with that statement. I don't think it was all a lean fueling issue. Detonation does that mostly. We run a lot of nitrous over here and see that in missed timing tune-ups.
I agree.  Frank's comment about the nitrous is spot on. Usually it is on the exhaust side but the relief lips are so thin on the intake side I can see where it would be taken out
 Send it back Johno and we'll fix it up. Be forewarned.....Kibblewhite has increased the price of the 5mm kit valves by about 85%!!!!!!!!!! :o. They are more expensive than their CRF Ti valves. WTF!
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Offline Bill/BentON Racing

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Re: Salt Racer CB 750 OZ style
« Reply #1188 on: March 31, 2015, 06:24:43 PM »
I vote no way I run that ignition again. That's f'in ugly, Too much for coincidence,  only other thing would be #2 carb/ fuel delivery, man, I FEEL for you, you'll get it, Bill
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Offline scottly

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Re: Salt Racer CB 750 OZ style
« Reply #1189 on: March 31, 2015, 07:00:31 PM »
WELL................ >:( >:(FCUK MY BROWN DOG SPOT >:(

My opinion.......................throw that fancy ignition to the #$%*house.
I'd have to agree with that statement. I don't think it was all a lean fueling issue. Detonation does that mostly. We run a lot of nitrous over here and see that in missed timing tune-ups.
I agree.  Frank's comment about the nitrous is spot on. Usually it is on the exhaust side but the relief lips are so thin on the intake side I can see where it would be taken out
 Send it back Johno and we'll fix it up. Be forewarned.....Kibblewhite has increased the price of the 5mm kit valves by about 85%!!!!!!!!!! :o. They are more expensive than their CRF Ti valves. WTF!
Running lean with nitrous will also smoke a piston in a heartbeat. ;)
I'm not a fan of those ignitions for several reasons... ::)
If both failures were due to a lean mixture, why on the #2 cylinder? Is there any chance there is a vacuum leak in the intake port? Easy to check by laying the head intake up and filling the spigot with kerosene or your liquid of choice.
The bottom of the piston is cooled and lubed by the oil flinging off the big end of the rod. Is there sufficient side clearance between the rod and the crank? Maybe there is a issue with the crank? 
Don't fix it if it ain't broke!
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Offline cbornotcb

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Re: Salt Racer CB 750 OZ style
« Reply #1190 on: March 31, 2015, 11:38:08 PM »
#2 huh Johnno,,,HOUSIE !
« Last Edit: March 31, 2015, 11:40:28 PM by cbornotcb »

Offline hotdog

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Re: Salt Racer CB 750 OZ style
« Reply #1191 on: March 31, 2015, 11:55:52 PM »
Throw an ARD on it for the next dyno run....sorry for your misfortune Johno
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Offline mick7504

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Re: Salt Racer CB 750 OZ style
« Reply #1192 on: April 01, 2015, 03:04:13 AM »
Twice in a row is called throwing down the gauntlet johno.
Feel pissed off for you mate.
Time to weed out the weak link and show it who the boss is.
You can do it.
We know that already.
If I was you
I'd be worried about me.

Offline johno

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Re: Salt Racer CB 750 OZ style
« Reply #1193 on: April 01, 2015, 03:08:45 AM »
oooh Tiny, there is something missing on the valve stem  :o :'(      valve bounce ?

Retro, I think your on the right track  :o

Hotdog, great minds think alike  ;D

Thanks Mike, I,ll send back a piece of blue insulation with it  ;)

had a night off tonight and just tidied up a very messy shed , couldnt resist something though I have a dual outlet pingle tap with equal length hose distribution,  I flowed all four outlets and all the same . The inlet rubbers were new again second time in row

So the next goal is Mike sort out the head, replace broken bits, rebuild engine, sort out the carbs, buy a normal ignition just in case, there were other things that indicate and confirm erratic ignition ( thats erratic Bear not erotic) on all the cylinders but I want to leave it at that.
 then replace the starting rollers with onboard starter like Dens, the rollers were a real pain

I think that will get things back on track, THEN Go back to the salt and nail it the first pass ;D 8).

So lets start, Hi Bill  ;) got any more pistons ?

Tiny you can have one of mine  ;D

cheers all Johno

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Offline MRieck

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Re: Salt Racer CB 750 OZ style
« Reply #1194 on: April 01, 2015, 05:04:37 AM »
I can assure everybody there was no vacuum leak secondary to the head on that cylinder. First off all the ports are vacuum checked on the Serdi after cutting and lapping the seats.
 If that cylinder was that lean to cause that kind of problem the paint would have been burnt off the # 2 pipe for about 3 feet and I seriously doubt it would get to 140mph on 3 cylinders. It also would have been vibrating badly. That piston has been pounded....not melted.
 I would invest in an MSD and book some dyno time. I would also measure pipe temps with an infra red while on the dyno.
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Offline Bill/BentON Racing

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Re: Salt Racer CB 750 OZ style
« Reply #1195 on: April 01, 2015, 06:30:05 AM »
Johno......I might. I'll look today for you!  Today!  ;D Bill
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Offline Bill/BentON Racing

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Re: Salt Racer CB 750 OZ style
« Reply #1196 on: April 01, 2015, 11:14:21 AM »
 ;D 61.90,61.92. One of each.
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Offline Bill/BentON Racing

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Re: Salt Racer CB 750 OZ style
« Reply #1197 on: April 01, 2015, 11:21:36 AM »
Used 61.90 both. Run very little. ;D
BentON Racing Website
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Over 35 years of experience working on vintage motorcycles, with a speciality in Honda SOHC/4 with a focus on the CB750 and other models as well from 1966 - 1985.
______________________________________
1993 HRC RS125 | 1984 NS400R | 1974 Honda CB750/836cc (Calendar Girl) | 1972 CB 500/550 Yoshi Kitted 590cc | 1965 Honda CB450 Black Bomber | 1972 Suzuki T350 | 1973 88cc | Z50/Falcons Pit Bike | 1967 CA100| 1974 CB350 (400F motor)...and more.
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Offline BPellerine

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Re: Salt Racer CB 750 OZ style
« Reply #1198 on: April 01, 2015, 05:11:37 PM »
with the ard even though it is old school you would only have one place to look for ign troubles,no wires,coils ,batt advance ,rough break johnno.billp
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Offline bear

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Re: Salt Racer CB 750 OZ style
« Reply #1199 on: April 01, 2015, 05:39:36 PM »
Provideuote author=MRieck link=topic=109584.msg1666278#msg1666278 date=1427889877]
 I would invest in an MSD and book some dyno time. I would also measure pipe temps with an infra red while on the dyno.

[/quote]
 
I'm with Mike Johno, MSD or established system with pickups that will provide a reliable signal.
"Optical pickups" and techno babble............. ::)

The old mags had their time in the sun in the 70's Hotdog/Bill and they did the job.
But there are more effective systems these days.

It's a shame your not a bit closer Johno.
I've got a mate with an old chassis dyno he brought from the local TAFF when they closed the automotive campus.
You just can't beat dyno time.
Having to line up for a 1hr session sucks.
It's neither you ass nor your elbow.

Cheers,
Brian


« Last Edit: April 02, 2015, 03:25:29 PM by bear »
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