Topic: Honda CB750 F or A 4-1 header - any good?

[Yamahawk]

Hi All,
   I am curious as to how well the 4-1 header and exhaust off of a 77-78 CB750F or A model works for a replacement for my 1971 CB750K model? My current exhaust is an aftermarket 4-2 model with large, Lake type pipe on each side, turned out to the side. The opening has to be 3" at least.
I have access to the 4-1 CB750F or A model, I believe it is anyway, as it came off of a 1970 CB750K0, and it looks like the stock exhaust off of a CB750F or A bike. I believe I could replace the rather long and heavy looking can on it with a lighter one. Would it perform as well as, say, a Kerker or Delkovic 4-1? I notice that it *may* block the oil filter housing, also. If anyone has had good experience running this exhaust, let me know. I am looking at weight reduction, ground clearance, etc. also as criteria for use. So... any good, or should I look elsewhere for a good 4-1 replacement?
Charlie

[slikwilli420]

A stock 4-1 for these bikes in good condition is worth a pretty penny to a lot of guys. It also weighs a ton more than a good aftermarket system and probably wont offer any more performance than the 4-4 pipes your bike came stock with. Go with the Delkevic or Motogpwerks pipe for a nice light solution.

[Stev-o]

+1 on MotoGP exhaust, I put one on my K3 earlier this year.

He doest have one currently listed, but send him a message [or call], he may have one laying around...

https://www.ebay.com/itm/KZ-1000-STAINLESS-4-1-KZ1000-Z1-Z1E-YOSHIMURA-CALFAB-RACE-AMA-KZ-KAWASAKI-ELR/112671395940?hash=item1a3bbd1064:g:IE0AAOSwyYFZ~LGx

[Yamahawk]

A stock 4-1 for these bikes in good condition is worth a pretty penny to a lot of guys. It also weighs a ton more than a good aftermarket system and probably wont offer any more performance than the 4-4 pipes your bike came stock with. Go with the Delkevic or Motogpwerks pipe for a nice light solution.

Thanks, slikwilli, it is in pretty good shape, has a little scrape on the muffler can, but the 4-1 header is almost perfect... it's at my friend Pat's cycle salvage, upstairs in the exhaust room. I figure it would look good, and looks like most of the weight is in that Looong can and pipe off the header lol. Someone must have taken it off of an F or A model and installed it on their K0. The tag says '70 CB750 on it.
Charlie

[Yamahawk]

Steve-o, thanks for the heads up. His stuff looks real good. I was considering the Delkevic with a light slip on can, as it looks very light and well built. The MotoGP pipe looks pretty nice also... have to sell a couple things to afford that one, though
Charlie

[seanbarney41]

Even the header weighs a metric #$%* ton...it will give back a little low end... enough to offset the weight?...I doubt it.  It's really heavy.  Also the collector is slightly oddball and it's hard to get a standard can to seal well.

[Garage_guy_chris]

also check out the Hindle pipes from http://www.ripplerockracers.com/product-category/exhaust-systems/ also very light and a similar 4-2-1 design

[Yamahawk]

The Hindle exhaust is nice, also, I used a small Hindle can on a header for a Kawasaki EX250 I am building for the track, looks like a nice light system.
Charlie

[Bankerdanny]

My 750F has what appears to be the stock header with a Kerker muffler. I haven't started it yet, so no idea about the sound, although based on the Kerker 4-1 on my 550F I expect it to be much louder than stock with a nice burble to it.

[Don R]

 I'm not sure if there is more than one A pipe but the ones I've seen aren't performance oriented. The 75/76F headers don't fit the k frame due to the brake pedal being different. 77/78F do fit K's.
 I like the delkevic for a 4-1 or DSS has the Yamiya stock no number pipes too.

[754]

Charlie you broke one if my rules,  fwiw..
Never ever, ever, ever or not even ever .....tell anyone on here where a nice piece that you are interested in is located.
If you then decide you don't want/need it, then and only then reveal where it us..
 Friendly advice fwiw..

[Yamahawk]

I'm not sure if there is more than one A pipe but the ones I've seen aren't performance oriented. The 75/76F headers don't fit the k frame due to the brake pedal being different. 77/78F do fit K's.
 I like the delkevic for a 4-1 or DSS has the Yamiya stock no number pipes too.

Thanks for the info, it might be a 77-78F model then. Not sure if the 77A is the same or not, but he has parted out at least two CB750A models, as the engines are on the shelf.

Charlie you broke one if my rules,  fwiw..
Never ever, ever, ever or not even ever .....tell anyone on here where a nice piece that you are interested in is located.
If you then decide you don't want/need it, then and only then reveal where it us..
 Friendly advice fwiw..

Hehe... yep, good advice, for sure 
But, I know that if something is in your path, there will be made a Way for it too. I am going to take a closer look at the exhaust system tomorrow, and see if there are any #'s on it or Honda markings anywhere on the header or can.
And as I once told another fellow, it is never, ever never or ever lol... only sometimes 

[Stev-o]

I'm not sure if there is more than one A pipe but the ones I've seen aren't performance oriented. The 75/76F headers don't fit the k frame due to the brake pedal being different. 77/78F do fit K's.
 I like the delkevic for a 4-1 or DSS has the Yamiya stock no number pipes too.

Thanks for the info, it might be a 77-78F model then. Not sure if the 77A is the same or not, but he has parted out at least two CB750A models, as the engines are on the shelf.

Charlie you broke one if my rules,  fwiw..
Never ever, ever, ever or not even ever .....tell anyone on here where a nice piece that you are interested in is located.
If you then decide you don't want/need it, then and only then reveal where it us..
 Friendly advice fwiw..

I am going to take a closer look at the exhaust system tomorrow, and see if there are any #'s on it or Honda markings anywhere on the header or can.

The Honda number should be stamped on the muffler

[Yamahawk]

Ok, couldn't find any Honda numbers anywhere on this header/muffler, but here are a couple pictures of it in case anyone can identify it. The header collector is flat, so it doesn't take much ground clearance, too. I actually found a 1975 CB750F model up there, and it was quite a bit meatier and HEAVY!
Charlie

[Yamahawk]

I added two of the same pic at first, now there is the view showing the flat 4-1 collector. oh.. and pay no attention to those CB550k pipes in the background...
Charlie

[seanbarney41]

If you use that on an f bike, you will have to source early model exhaust spigots.  And no Honda numbers because it is aftermarket.

[Yamahawk]

If you use that on an f bike, you will have to source early model exhaust spigots.  And no Honda numbers because it is aftermarket.

Sean,
   It's going on a 1971 CB750K1, the tag on the exhaust says 1970 CB750, so it should fit my spigots already. Any idea who made this exhaust? I figured it was aftermarket after not finding any Honda #'s or logo's on it. So not sure exactly what it is, and how well it will perform... and, it's really not that heavy either. Not like the 1975 CB750F hanging opposite it, but it's not in either picture. I noticed the muffler has a bracket welded on it to fit the mount point on the K0 frame, so the pipe isn't really made to fit to early k's for some reason, or he just used a can he had laying around for the header.
Charlie

[seanbarney41]

Oh that's right...forgot it was going on k1.  No idea what kind that is.  Somewhere here is an exhaust I'd thread.  Somebody needs to search it up as there is lots of good info therein

[Yamahawk]

Thanks! I will search and see if I can find it
Charlie

[754]

It is set up for spigots, may be a one off.
 Bet it won't fit an F, which wasn't invented when this was built.

[Yamahawk]

It is set up for spigots, may be a one off.
 Bet it won't fit an F, which wasn't invented when this was built.

Yeah, I am not sure of this pipe, either. Definitely NOT an F pipe, but then, it may be just an early 4-1 header for the CB750. Perhaps he had a spare can laying around, and installed it on his K0. I know it should have good ground clearance with the flat collector, just not sure how well this design would perform. Most collectors are 4 square, and then taper into a single outlet for the muffler can or pipe to flange to. But, if there is evidence somewhere as to how well this header system works, that would be cool. I could install it and try it out, but winter is coming fast lol... may have to wait for the global warming I am praying for
Charlie