Topic: Best cheap mods for the CB750

[PeWe]

Talk about going down memory lane ... For the most part this 750 article is dated and many of the specific parts mentioned are no longer available. It's a bit on the long side, but still a good read for all SOHC 750 owners.

Honda 750 Update - Taking it into the 80's
by Joe Minton
Published in Motorcyclist, August 1981

....

This should be in a sticky or FAQ, very useful, thanks for posting!

Good reading, I saved it some years ago when I was searching for new rings. Mentioned that pistons used CB350 65mm piston rings. Ended up in NOS even older RC.
- Cam can be ordered from Dynoman, DP295.
- 836cc pistons too but not the old Action Fours. I have them in a box in my garage:-)

[pamcopete]

Pickup a slotted cam gear and degree the cam. Slight changes in the cam timing can mean big changes in where the power comes on and how much power you get out.

Changing the 630 chain setup to a 520 chain setup makes a pretty big difference as well. The 520 is much lighter and will translate to a quicker response on the road.

Upgrade the brakes to a dual piston setup. I picked mine up from a VT1100C for like $70 on ebay. Makes it a little sportier looking too.

Change out the points ignition to a PAMCO or Dynatek. Although that might be out of the "cheap" scope as I think that's around $300 although the Dynatek plate is around $100 if memory serves.

You can get a PAMCO basic system for $119.95 and use your stock coils, although I do recommend that you replace the spark plug caps as they will often go open circuit.

[CycleRanger]

Cheap mods:

Pods
Mac exhaust
Keyster carb kits
Cheng Shin tires
Chinese clubmans

iseewhatyoudidthere.jpg

[PeWe]

Pickup a slotted cam gear and degree the cam. Slight changes in the cam timing can mean big changes in where the power comes on and how much power you get out.

Changing the 630 chain setup to a 520 chain setup makes a pretty big difference as well. The 520 is much lighter and will translate to a quicker response on the road.

Upgrade the brakes to a dual piston setup. I picked mine up from a VT1100C for like $70 on ebay. Makes it a little sportier looking too.

Change out the points ignition to a PAMCO or Dynatek. Although that might be out of the "cheap" scope as I think that's around $300 although the Dynatek plate is around $100 if memory serves.

You can get a PAMCO basic system for $119.95 and use your stock coils, although I do recommend that you replace the spark plug caps as they will often go open circuit.

I bought the Ultimate kit when the coils should cost much more if adding them later on. My OEM coils looked rather rotten and I did not trust them after 20 barn years.  That was a relatively cheap upgrade from basic.... everything fresh

[andrewk]

I am going to toss this out for you, to the F guys. Is there any sprocket/chain alignment issues going with a silver 1976 F1 engine into the later black engine 1978 frame ? Reason I wonder for you is that swapping K engines etc from earlier years to later and different model frames etc. can create some issues with those components.

I only noticed that mine is still using the 630 chain and sprockets. To my (small amount of) knowledge the F1 and F2 frame is practically the same (but I may be wrong). The most prominent differences as I see it are the wheels (and front brakes) and engine.

F2/3 has same issue with early engines as K7/8.  Late K/F engines have a 10mm longer output shaft, wider swingarm (old style will bolt up but left upper shock mount is offset 10mm as well) and taller sprocket carrier to compensate for the longer output shaft.

Early engine in a late frame is pretty easy, because you can use an early sprocket carrier and some custom spacers on the sprocket side of the axle and it will be just fine.   Late engine in a early frame is a bit harder.

[TaterMasher]

Hello everyone!

Please excuse my newbishness. I'm new to CB's and new to this forum (as you can tell). I picked up a 74 CB750 about a month ago now. As is typical, Ive found the front brake is soft. MadScientist mentioned using a dual piston from a VT1100C. Has anyone else used this? What additional modifications are needed to make it work?

Thanks for any advice and it's great to join you all! 

[flybox1]

Hello everyone!

Please excuse my newbishness. I'm new to CB's and new to this forum (as you can tell). I picked up a 74 CB750 about a month ago now. As is typical, Ive found the front brake is soft. MadScientist mentioned using a dual piston from a VT1100C. Has anyone else used this? What additional modifications are needed to make it work?

Thanks for any advice and it's great to join you all! 

welcome newbie!
first...use the search bar upper left to find threads on subjects.  tons on brake fixes
second, if you want good responses to your questions, start your own thread.
third - download the shop manual from teh FAQ section.  it will help you more than you know.

as far as  your brake is concerned, why not get a stock caliper working first, and complete all of the 3000mi suggested maintenance items to see how your bike runs and what it needs, before jumping into a huge mod like dual fronts....just my $.02 

[TaterMasher]

welcome newbie!
first...use the search bar upper left to find threads on subjects.  tons on brake fixes
second, if you want good responses to your questions, start your own thread.
third - download the shop manual from teh FAQ section.  it will help you more than you know.

as far as  your brake is concerned, why not get a stock caliper working first, and complete all of the 3000mi suggested maintenance items to see how your bike runs and what it needs, before jumping into a huge mod like dual fronts....just my $.02 

Thanks for your 2 cents and direction flybox1. I will be checking out the shop manual.

[madScientist]

For the VT1100c swap that I did nothing additional was needed. I bought the complete front assembly; brackets and calipers. You "might" need different banjo bolts but my set came with them so I used them. The set i purchased were in good, usable condition so i tossed them on and off I went. Even came with a decent set of pads.

I also replaced the brake lines with stainless lines.