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Which service manual to get?
- Thread starter swiedom
- Start date
Dave
CB750 Junkie
From the descriptions I prefer the 2nd one you linked. Are they better then a Clymer? No, they are different.
Shop manuals assume your an experienced mechanic. Clymers assume you have some mechanical aptitude.
I prefer digital copies as I have an old laptop out in the garage I use for them.
You can download these for free. See this thread http://www.cb750.com/threads/828-79-83-CB750-Service-Manual-in-PDF-Format?p=6058&viewfull=1#post6058
Shop manuals assume your an experienced mechanic. Clymers assume you have some mechanical aptitude.
I prefer digital copies as I have an old laptop out in the garage I use for them.
You can download these for free. See this thread http://www.cb750.com/threads/828-79-83-CB750-Service-Manual-in-PDF-Format?p=6058&viewfull=1#post6058
amc49
CB750 Guru
X2, insane to pay when you can get it for free. I like hard copy too but not enough to do that. The first one if in original form is looseleaf sheets anyway to fit in a company binder. I have one. Look at the punched holes on the right. The second one may well be a standalone perfect bound book, it has no holes.
X3... these are from Honda and correct... Clymers is a separate company and the are known for having many, many errors in them... That's where I disagree with Dave unless just different refers to being accurate or inaccurate. ..
BipolarHeart
CB750 New member
I currently use two different ones for mine
1982 NightHawk CB750SC
1982 NightHawk CB750SC
Never had good luck with clymer either. A REAL Honda manual is the best, if they do have errors they put out addendums. Watch ebay for manuals, you can get them dirt cheap if you watch for them,
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amc49
CB750 Guru
Honda themselves make errors, like the valve clearance minimums on DOHCs, they are too close. Why? Because the cam-in-head clearances are too loose. A bizarre situation where the cam/head clearances change down the length of the cams. Kinda goofy, what were they thinking? Why tight on valves lets them effectively be closed while running even if you show all day long to have clearance. It's not real. You're trying to set .003" in a looseness of up to almost .008" and every time you move the engine the springs shove the cams around in the big slop to screw with your valve numbers. Why we teach to always set the valves at .005", your valve setting events then go for MUCH longer then with zero issues and the motors then run spectacularly.
There's another where it's wondered what Honda engineers were thinking when the carb spacing and actual port casting in head done and numbers set in concrete, a mistake there on virtually every one you look at has the head casting messed up to probably toss another 5-10 hp. for no reason at all by unnecessarily kinking the crap out of the intake port. The valve pockets are not centered on the valves either, the machine points in space are messed up.
There's a Kiwi racer on the 1100 site that has remachined a head to remove all that and the engine which pretty much hit an all out hp. limit of around 150 is suddenly going up close to 180 or so in full race trim now. Enough to start tearing out brand new primary chain drives in one race now and forcing him to go to gear drive primary. He's putting out more power now than Honda ever thought they could get out of them. The head is available to those with the cash, around $5000 a copy IIRC. He as well has made up cam chain guides that make the chains last much longer under racing stress too, a design flaw there corrected too.
There's another where it's wondered what Honda engineers were thinking when the carb spacing and actual port casting in head done and numbers set in concrete, a mistake there on virtually every one you look at has the head casting messed up to probably toss another 5-10 hp. for no reason at all by unnecessarily kinking the crap out of the intake port. The valve pockets are not centered on the valves either, the machine points in space are messed up.
There's a Kiwi racer on the 1100 site that has remachined a head to remove all that and the engine which pretty much hit an all out hp. limit of around 150 is suddenly going up close to 180 or so in full race trim now. Enough to start tearing out brand new primary chain drives in one race now and forcing him to go to gear drive primary. He's putting out more power now than Honda ever thought they could get out of them. The head is available to those with the cash, around $5000 a copy IIRC. He as well has made up cam chain guides that make the chains last much longer under racing stress too, a design flaw there corrected too.
amc49
CB750 Guru
By the way, lots of sources like those manuals claim the DOHC electronic ignition is a CDI, it is NOT, only a simple transistorized type that replaces points.
You have stated a lot of opinion... and I am not disagreeing with your opinions entirely either...
Honda does do this... I have a healthy respect for their products, manufacturing, quality and service. Lots of 35 year old Honda motorcycles out there running strong...
With regards to the OP question, Clymers can't begin to compare to a Honda FSM...
amc49
CB750 Guru
.............as long as you don't make them make any more power than stock.
They seem to go out of their way to make sure if you like to mod for power you will pay a lot more than other makes. Why you really don't see them much in any bike racing other than where they limit you to pretty much stock stuff. Take drag racing, the bigger Hondas blew up while the Kawasakis and Suzukis just got faster and faster, the basic engines were quite a bit stronger. Honda runs fine until you mod it then problems everywhere. Think CBR1100XX. Flimsy and overheats. Think CBX, the most impressive bike engine ever done, it has little midrange and if you overbore it begins to overheat like an oven. They blow up left and right from more cam-in-head issues, the cam ends have OPEN HOLES that leak oil to fail main bearings. The cam joints give fits. Take the SOHC, the doublechain primary drive broke on great bunches of them once you put any serious power in there, often the countershafts tore out of them too. None of the other big bikes did that. No addendums, they simply detune them to do it less. I know one guy whose Dad owned a big Honda shop and the SOHC chain busting thing almost bankrupted them he said it happened so much. Stock early bikes and why they slowed them down. I forgot to add that the cam chain guide thing is why Freddie Spencer was told by Honda to never rev the DOHC engine over 9500, 'they blow up at ten' he said. The biggest issue they had was blowing up engines over and over they quite literally could not keep them together. The Kiwi racer mentioned above spins his at 12000 rpm and no failures in cam drive doing it.
'Lots of 35 year old Honda motorcycles out there running strong...'
I rest my case, a good indicator of how well most can tune things. My lawn mower is 18 years old..............
Don't feel bad, I treat the Harley guys worse. There was one that owned a shop here in the Metroplex, he used to bring in his Camaro street racer for us to work on. He had what at the time was an ungodly big S&S 105" (IIRC) Sporty horod that was 'the fastest thing ever built'. Unfortunately I had just run into 3 guys the night before that had started a CBX ratpack. I pulled over on my DOHC and one of them wanted to ride it bad and we traded bikes, whereupon I proceeded to see what CBX power was all about. I flogged the living crap out of that bike with his blessing and was soundly impressed. 125+ on the freeway at 9000 rpm at night will do that to you. The next day I run into Harley guy, who had brought his bike by to let me ride it, he knew I was a biker. I took that one out and abused it too and brought it back and he pestered me for 20 minutes before I finally quietly told him the dead stock CBX I rode the night before would stomp it into the ground. BOY, he was not pleased at that at ALL. The Harley was probably a low 12- 12 flat second bike and killer for a Harley back then but the CBX was a '79, the one that driven hard off the line could produce 11.50 1/4 mile times. TOO fast, the Europeans were crying about it and the next year Honda detuned the crap out of the cams to toss 10+ hp. quicker than you can say.
Man I did love the way that big six sounded.
They seem to go out of their way to make sure if you like to mod for power you will pay a lot more than other makes. Why you really don't see them much in any bike racing other than where they limit you to pretty much stock stuff. Take drag racing, the bigger Hondas blew up while the Kawasakis and Suzukis just got faster and faster, the basic engines were quite a bit stronger. Honda runs fine until you mod it then problems everywhere. Think CBR1100XX. Flimsy and overheats. Think CBX, the most impressive bike engine ever done, it has little midrange and if you overbore it begins to overheat like an oven. They blow up left and right from more cam-in-head issues, the cam ends have OPEN HOLES that leak oil to fail main bearings. The cam joints give fits. Take the SOHC, the doublechain primary drive broke on great bunches of them once you put any serious power in there, often the countershafts tore out of them too. None of the other big bikes did that. No addendums, they simply detune them to do it less. I know one guy whose Dad owned a big Honda shop and the SOHC chain busting thing almost bankrupted them he said it happened so much. Stock early bikes and why they slowed them down. I forgot to add that the cam chain guide thing is why Freddie Spencer was told by Honda to never rev the DOHC engine over 9500, 'they blow up at ten' he said. The biggest issue they had was blowing up engines over and over they quite literally could not keep them together. The Kiwi racer mentioned above spins his at 12000 rpm and no failures in cam drive doing it.
'Lots of 35 year old Honda motorcycles out there running strong...'
I rest my case, a good indicator of how well most can tune things. My lawn mower is 18 years old..............
Don't feel bad, I treat the Harley guys worse. There was one that owned a shop here in the Metroplex, he used to bring in his Camaro street racer for us to work on. He had what at the time was an ungodly big S&S 105" (IIRC) Sporty horod that was 'the fastest thing ever built'. Unfortunately I had just run into 3 guys the night before that had started a CBX ratpack. I pulled over on my DOHC and one of them wanted to ride it bad and we traded bikes, whereupon I proceeded to see what CBX power was all about. I flogged the living crap out of that bike with his blessing and was soundly impressed. 125+ on the freeway at 9000 rpm at night will do that to you. The next day I run into Harley guy, who had brought his bike by to let me ride it, he knew I was a biker. I took that one out and abused it too and brought it back and he pestered me for 20 minutes before I finally quietly told him the dead stock CBX I rode the night before would stomp it into the ground. BOY, he was not pleased at that at ALL. The Harley was probably a low 12- 12 flat second bike and killer for a Harley back then but the CBX was a '79, the one that driven hard off the line could produce 11.50 1/4 mile times. TOO fast, the Europeans were crying about it and the next year Honda detuned the crap out of the cams to toss 10+ hp. quicker than you can say.
Man I did love the way that big six sounded.
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I don't, no worries... You are a true mechanic, and you prob like to experiment . I'd ask for your advice anytime but I like stock and restoration more than chopping, cafe'in, supin, etc... I'm not gonna race anything at my age, lol...
Just got the electronic version and actually, it looks like the first link is the same as the electronic version. Anyone own/prefer the book in the second link?
amc49
CB750 Guru
I'd bet that being the official service manual they have exactly the same guts, only cover changed. One simply a later version. As long as more types or years not added the same. Seen it on others.
I would ignore the OEM valve clearance given and use .005" as the number to go for and no less than .004" for sure. The pulsers work better closer too, I use no less than .012".
I would ignore the OEM valve clearance given and use .005" as the number to go for and no less than .004" for sure. The pulsers work better closer too, I use no less than .012".
