In the 1970s when I still rode, i owned 3 of these, to include a K0. Used to do my own work because dealer work was not up to par. When the K0s came out the plugs tended to foul. The advent of platinum tip NGKS solved the problem.
Oh wow. A sand cast cb750k? Those are becoming incredibly rare. The plug fowling is an issue on my bike but I suspect the reason to be bored out jets (likely caused by improper cleaning tools).
Mine was a production model. Only the early K0s were sand cast. You can tell by the side covers. When I bought my 750-4 in 1970 it came with the old type link chain with the removable cotter like I had on a Triumph Bonneville I had. The chains were breaking and holing the case. Honda recalled mine to replace the chain with the endless variety and with a higher toothed countershaft sprocket. The original was 13 teeth. This reduced performance somewhat which was disappointing. I first saw the 750-4 in late 1968 at the Tokyo Motor Show. I was on assignment in the USAF to Japan back then. The early bikes carb setup was with a separate cable going into each carb. Hard to setup -- you had to have a vacuum guage setup as well. In the a later Honda four, I installed a kit with Delco Remy points that could be adjusted with an Allen wrench like the Corvette I had back then. All you needed was dwell meter -- timing light as well. And everyone knows about changing the oil filter -- not to break the bolt holding the filter cover in place.
Boy I'll tell ya, I wish I had some of those bars protecting my points cover on my KZ650. Had someone pull a U-turn into a few weeks ago, and shattered the crankcase where the points cover is. Only damage on the whole bike aside from a chipped blinker lense. Now I've either got to find a way to fabricate a new cover, or replace the entire motor 😔😔
Glad to see you post up a vid! Yeah, I was replacing the caps on my 72' 750 and quickly realized I could not clip any more off of them. Was a great excuse to buy new coils as the wires on that bike were molded into the coils. :)
Factory and factory style always are. When I bought my green bike it came with... CAME WITH... A set of 3ohm dyna coils and a dyna S ignition! I need to get those puppies installed soon. They obviously don't have the wires molded to them 😋
You can use coils off the older years goldwings. That way you can just replace the wires if needed. They are cheaper and work great. I use them on my 1972 cb750
Also your valve lash should 5 thousands of an inch for intake valve and 8 thousands of an inch exhaust but I heard from other Honda owners that setting the valves a little more then spec helps save on burning out the valve seats and cams as fast compared what they originally thought and designed back in the 70’s
Incorrect! Valve clearance should be 0.002" for intake and 0.003" for exhaust. However!!!!! That translates to 0.05 mm and 0.08 mm!! I think that might be where you're five and eight came from.
Don't you need to check to make sure cylinder one is at top dead center before doing the cam chain adjuster? (Or did I miss that part? I skipped ahead to the cam chain part of the vid.)
@@Mike_Barker Your videos have been very helpful. I recently bought my first motorcycle, a 1975 CB750. I knew nothing about bikes or mechanics, but I've been able to do some work on it thanks to vids like yours and that dude from hackaweek. I actually took the carbs off and fixed a couple issues I was having. I'm going to do a carb sync and a cam chain adjustment tomorrow. (How do I know if the cam chain needs adjusting?)
The cam chain will make a bit of a slapping sound when running. After the adjustment the bike should be back to its typical Honda sewing machine sound. 😆
Hey. Enjoying your videos. I just purchased a 1971 cb 750. I was told the engine had been gone over, carb kits etc etc. once fired up you have to have the choke open for 8-10 minutes before it will run by itself. Sputters and coughs for another 10 minutes till it straitens out. Any suggestions on where to start ? Or maybe I’ll just go through everything on it like Ron burgundy.
The work begins! I love old bikes!!!!!! I don't love every single thing about them... BUT I STILL LOVE EM'!!
In the 1970s when I still rode, i owned 3 of these, to include a K0. Used to do my own work because dealer work was not up to par. When the K0s came out the plugs tended to foul. The advent of platinum tip NGKS solved the problem.
Oh wow. A sand cast cb750k? Those are becoming incredibly rare. The plug fowling is an issue on my bike but I suspect the reason to be bored out jets (likely caused by improper cleaning tools).
Mine was a production model. Only the early K0s were sand cast. You can tell by the side covers. When I bought my 750-4 in 1970 it came with the old type link chain with the removable cotter like I had on a Triumph Bonneville I had. The chains were breaking and holing the case. Honda recalled mine to replace the chain with the endless variety and with a higher toothed countershaft sprocket. The original was 13 teeth. This reduced performance somewhat which was disappointing. I first saw the 750-4 in late 1968 at the Tokyo Motor Show. I was on assignment in the USAF to Japan back then. The early bikes carb setup was with a separate cable going into each carb. Hard to setup -- you had to have a vacuum guage setup as well. In the a later Honda four, I installed a kit with Delco Remy points that could be adjusted with an Allen wrench like the Corvette I had back then. All you needed was dwell meter -- timing light as well. And everyone knows about changing the oil filter -- not to break the bolt holding the filter cover in place.
Wow! Really great info. Thanks for sharing the story too!
Boy I'll tell ya, I wish I had some of those bars protecting my points cover on my KZ650. Had someone pull a U-turn into a few weeks ago, and shattered the crankcase where the points cover is. Only damage on the whole bike aside from a chipped blinker lense.
Now I've either got to find a way to fabricate a new cover, or replace the entire motor 😔😔
Glad to see you post up a vid! Yeah, I was replacing the caps on my 72' 750 and quickly realized I could not clip any more off of them. Was a great excuse to buy new coils as the wires on that bike were molded into the coils. :)
Factory and factory style always are. When I bought my green bike it came with... CAME WITH... A set of 3ohm dyna coils and a dyna S ignition! I need to get those puppies installed soon. They obviously don't have the wires molded to them 😋
Yeah, Dyna coils and ignition are next on the list for my 75 CB550.. They are on a shelf over at Godfferys garage waiting on me. :)
Sooooo good!
You can use coils off the older years goldwings. That way you can just replace the wires if needed. They are cheaper and work great. I use them on my 1972 cb750
Rick, that's a great piece of information for folks. Thanks for that! I'm curious as to how easy those coils are to track down. Can you buy them new?
You didn't set it at 15 degrees past TDC to set the tensioner?
Very helpful thanks!!
You didn't put in your video to put number one at top dead center compression stroke and why did you start on number 4 cyl ?
Also your valve lash should 5 thousands of an inch for intake valve and 8 thousands of an inch exhaust but I heard from other Honda owners that setting the valves a little more then spec helps save on burning out the valve seats and cams as fast compared what they originally thought and designed back in the 70’s
Incorrect! Valve clearance should be 0.002" for intake and 0.003" for exhaust. However!!!!! That translates to 0.05 mm and 0.08 mm!!
I think that might be where you're five and eight came from.
Cam chain should be adjusted 10° after top dead on #1
Yup! To make sure the slack is totally out of it before you use the adjuster. 👍 I forgot to mention it when I did this video. 😔
rad randy bowler that’s 15% after crankshaft is top dead center of No. 1 cylinder
thank you this vid was helpful
You're welcome! I'm glad it provided value to you.
Your videos are great! Thanks
Ah thanks David! I'm going to try and get them out more regularly. I really do enjoy making them.
Don't you need to check to make sure cylinder one is at top dead center before doing the cam chain adjuster? (Or did I miss that part? I skipped ahead to the cam chain part of the vid.)
I goofed! It should be at 15 degrees AFTER top dead center on cylinders 1+4. Good catch! I'll have to update this process
@@Mike_Barker Your videos have been very helpful. I recently bought my first motorcycle, a 1975 CB750. I knew nothing about bikes or mechanics, but I've been able to do some work on it thanks to vids like yours and that dude from hackaweek. I actually took the carbs off and fixed a couple issues I was having. I'm going to do a carb sync and a cam chain adjustment tomorrow. (How do I know if the cam chain needs adjusting?)
The cam chain will make a bit of a slapping sound when running. After the adjustment the bike should be back to its typical Honda sewing machine sound. 😆
Hey. Enjoying your videos. I just purchased a 1971 cb 750. I was told the engine had been gone over, carb kits etc etc. once fired up you have to have the choke open for 8-10 minutes before it will run by itself. Sputters and coughs for another 10 minutes till it straitens out. Any suggestions on where to start ? Or maybe I’ll just go through everything on it like Ron burgundy.
Sounds like carbs to me. I'd go over the entire engine with a fine tooth comb though. All the basic service adjustments.
@@Mike_Barker ok will do. Thanks man.
what size wrench did you use? as I just bought a 76 Honda CB750 bobber
Mike stop making kids and make videos again. 👍