Topic: Which exhaust pipes for which years/model?

[ev0lve]

Just poking around on eBay looking at exhaust pipes and it occurs to me that I don't know which years/models share the same specs which gives me the fear. Dynoman has a Kerker which lists these years as equivalent.

CB750 SOHC Honda
1970-78 CB750K
1975-78 CB750F

Does anyone have a quick rundown on what pipes fit which model/years without modification and when they switch from clamps to flanges on the pipes? Mount points the same? Or does it matter; just install some studs/bracket for the hanger? Is the spec above right? No gotchas?

Thanks!

[dusterdude]

iggy,all k pipes of the same head mounting variety will interchange.i think the change from spigot to stud mount was in 1975 give or take a year.the f model pipes are the same,i think,and will not interchange with k models.if im wrong im sure someone will correct me.

[Geeto67]

1969-1976K bikes use flanges. 1975-1978 F bikes use studs. Not sure about the 77-78K bikes or the hondamatics. However you can convert one to the other and vice versa. If you buy a kerker you will have to convert your flange head to studs, it is just a matter of knocking out the screws holding the flanges in and screwing the studs in their place.

With aftermarket exhausts, usually there is a universial rear flange mount and different brackets to mount the rear of the pipe to the frame (like with the kerkers). Mac makes different slip on mufflers that are model specific, but even still you can just adapt them. Basically with aftermarket pipes, anything can be made to fit with the appropriate brackets.

if you are looking for stock pipes here are the different basic breakdowns that are true bolt ons with no modifications:

1969-1976K  4 into 4
1975-1976F 4 into 1
1977-1978F 4 into 1
1977-1978 4 into 4

[736cc]

  HM300 pipes sound a gazillion times better than HM341 pipes. Faster, too.

[ev0lve]

If I could find some stock pipes I could afford I'd DEFINITELY do that but man those are pricey. At this point I'll be happy with a rusty Kerker I can clean up and paint black

[Geeto67]

Mac pipes are definatly affordable. Not really a performance upgrade but I like the sound on mine (to be fair I like the sound of my 4 into 4 K5 better). A new mac is less than $300 shipped. If you do go this route buy a black one and recoat it with high heat paint, mac finishes tend to suck including their chrome. But for budget sake it isn't a bad new pipe.

Cycle ex, Yamyia, and kerker all make good 4 into 1s. If it were up to me and I was spending $500 on an exhaust I would buy the Yamyia exhaust.

Any aftermarket exhaust is going to require you to change to studs from the spigot.

If you think hm341's are expensive you should see what hm300s go for.

[ev0lve]

If I had the cash I'd get BCR to make up a set of these but that's why I'm poking around on eBay 

[ev0lve]

Just scored a Kerker on eBay but I'll have to swap out the spigots for studs. My local Honda shop is closed due to snow so I'm poking around the interweb looking for some.

Would someone point me at a resource to purchase these online (there's a couple eBay auctions in the UK I can find) or give me the specs I should know to pick them up from Tacoma Screw?

Any other words of wisdom on making the swap?

Thanks!

[Johnie]

  HM300 pipes sound a gazillion times better than HM341 pipes. Faster, too.

Just curious, what makes the 300's sound better than the 341's?  Is there just a difference in the baffles or some other feature?  I have to admit I do like the sound of my 300's.

[736cc]

  Basically, the 300's have bigger diameter outlet size in its baffle, and the innards of the muffler almost a straight pipe. The 341's have a tiny diameter outlet, and baffle chambers are in the muffler (the end caps are just for show, and aren't really a baffle). The 300's w/o diffusers sound REALLY good (and can shoot flames when they backfire if you do it right), but too loud for daily riding. A neat trick is to remove the 300 diffusers and hacksaw-off the inner end, then replace the diffusers. A little more breathing and a tad more bark the result. You can also mod the 341's by removing the end cap and drilling out the internal chamber wall w/ a few 1/4" holes.
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[ev0lve]

Just scored a Kerker on eBay but I'll have to swap out the spigots for studs. My local Honda shop is closed due to snow so I'm poking around the interweb looking for some.

Would someone point me at a resource to purchase these online (there's a couple eBay auctions in the UK I can find) or give me the specs I should know to pick them up from Tacoma Screw?

Any other words of wisdom on making the swap?

Thanks!

Found it I think. 6mm thread / 45mm long

That's correct for a 75K? I keep seeing threads about people not able to get the engine out because the exhaust studs are too long. Seems that has to do with 77 and DOHC models? Any clarification appreciated.