Author Topic: Keilhin vs. Mikuni for 77 Honda CB 750K7.  (Read 10771 times)

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Offline Retro Rocket

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Re: Keilhin vs. Mikuni for 77 Honda CB 750K7.
« Reply #25 on: August 16, 2013, 09:24:24 pm »
Doesn't the weather tune SU's..?   ;D :o
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If You can't fix it with a hammer, You've got an electrical problem.

Offline scottly

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Re: Keilhin vs. Mikuni for 77 Honda CB 750K7.
« Reply #26 on: August 16, 2013, 09:42:04 pm »
Didn't the old SU's have oil-damped pistons? I guess in colder weather, the oil would have been thicker, and slowed down the opening?
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Offline scottly

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Re: Keilhin vs. Mikuni for 77 Honda CB 750K7.
« Reply #27 on: August 16, 2013, 09:44:16 pm »
Webers and Dellorto's are "Unobtainium" nowadays, although I wouldn't mind a pair of downdraft Webers on my new 'Wang project, but SU's? Uuuurrrggghhh............. ;D

They're the original CV's Terry, very easy to tune, just needle tapers to work with.  That said there are a couple of hundred to choose from. ;) :)

Yeah I know, and I shouldn't hang snit them Brian, My dad's got twin SU's on his 1975 Triumph TC2500, and they're still in tune after almost 40 years. I just had a bad experience with an SU off a Mini that I installed on my 1948 Royal Enfield 350 engine that I had in my Go Kart catching fire. Once my hair grew back I was OK though............. ;D

That sounds more like an Anal issue rather than an SU issue. ;D ;D ;D ;D
"SU issue" >:( Hmm...................Sounds like I'm sneezing.

Cheers,
Brian
Fixed it for you, Brian. ;)
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Offline bear

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Re: Keilhin vs. Mikuni for 77 Honda CB 750K7.
« Reply #28 on: August 16, 2013, 11:57:19 pm »


That sounds more like an Anal issue rather than an SU issue. ;D ;D ;D ;D
"SU issue" >:( Hmm...................Sounds like I'm sneezing. :o ::)

Cheers,
Brian
[/quote]
Fixed it for you, Brian. ;)
[/quote]

Jeez Scott,
Now it sounds like I've got piles and a cold.

Cheers,
Brian
The older I get the faster I was.

Offline Terry in Australia

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Re: Keilhin vs. Mikuni for 77 Honda CB 750K7.
« Reply #29 on: August 17, 2013, 02:10:24 am »
Didn't the old SU's have oil-damped pistons? I guess in colder weather, the oil would have been thicker, and slowed down the opening?

Dad's SU's have oil damped pistons, but it's really thin oil Scott, so I don't think the colder weather would do much? But I don't know for sure. Cheers, Terry. ;D
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Offline dusterdude

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Re: Keilhin vs. Mikuni for 77 Honda CB 750K7.
« Reply #30 on: August 17, 2013, 06:29:57 am »
I had an su on my panhead many moons ago,didnt like it
mark
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Offline 754

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Re: Keilhin vs. Mikuni for 77 Honda CB 750K7.
« Reply #31 on: August 17, 2013, 08:30:41 am »
Was it a Rivera Engineering, or a self setup one ?

 The Rivera ones worked very well.. Got about 60 mpg going to Sturgis on my buddies chopper.
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Offline Tintop

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Re: Keilhin vs. Mikuni for 77 Honda CB 750K7.
« Reply #32 on: August 17, 2013, 08:59:09 am »
Doesn't the weather tune SU's..?   ;D :o

No that's Webers RR.  That said, most Brit sports cars seem'd to like wet weather, an automotive form of home sickness? ;) :)

Didn't the old SU's have oil-damped pistons? I guess in colder weather, the oil would have been thicker, and slowed down the opening?

I always used ATF as the dampening fluid scottly.  Never had a problem, even driving the MGB in sub zero Toronto weather.  Of course I was also wrapped in a blanket as the MG's heater wasn't worth sh*t. ::)
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Offline Retro Rocket

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Re: Keilhin vs. Mikuni for 77 Honda CB 750K7.
« Reply #33 on: August 18, 2013, 02:29:10 am »
Doesn't the weather tune SU's..?   ;D :o

No that's Webers RR.  That said, most Brit sports cars seem'd to like wet weather, an automotive form of home sickness? ;) :)

Didn't the old SU's have oil-damped pistons? I guess in colder weather, the oil would have been thicker, and slowed down the opening?

I always used ATF as the dampening fluid scottly.  Never had a problem, even driving the MGB in sub zero Toronto weather.  Of course I was also wrapped in a blanket as the MG's heater wasn't worth sh*t. ::)

I had mates that had triple SU's on their hotted up 6 cylinder Holdens, it was all the rage here in the 70's and early 80's maybe its the humidity  where I live but if the weather changed the bloody things went out of tune, it was common to hear guys saying that they didn't like them because of that very reason.....  Just saying... ;)
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If You can't fix it with a hammer, You've got an electrical problem.

Offline Tintop

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Re: Keilhin vs. Mikuni for 77 Honda CB 750K7.
« Reply #34 on: August 18, 2013, 06:16:23 am »
Did a conversion for a guy from Strombergs to SU's on a Triumph TR4A.  He P/U'd and didn't see him again for 2 years.  When I did asked him when he'd like the carbs tuned, said they didn't need it.  Just saying. ;) ;D ;D ;D ;D
1977 CB550/4 Cafe - Speed Warrior / BOTM 03/11
1980 CB750F (project)
Whittaker GBF Vintage Racing Sidecar (XS750 power) - ITG / 151's / CMR Racing Products (SOLD)
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550/750 Filter Thread
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Offline Retro Rocket

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Re: Keilhin vs. Mikuni for 77 Honda CB 750K7.
« Reply #35 on: August 18, 2013, 02:41:05 pm »
Being a pommy carb I think they must like colder weather... ;)
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline Tintop

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Re: Keilhin vs. Mikuni for 77 Honda CB 750K7.
« Reply #36 on: August 18, 2013, 04:10:17 pm »
Being a pommy carb I think they must like colder weather... ;)

Yeah, and Webers can only be tune properly if you have tomato sauce on your fingers. ;D ;D ;D ;D ;D ;D ;D

Seems like we've highjack this thread long enough RR.  Still waiting for Terry to join back in with his alternative, that was 'on the horizon'.
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550/750 Filter Thread
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Offline Retro Rocket

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Re: Keilhin vs. Mikuni for 77 Honda CB 750K7.
« Reply #37 on: August 18, 2013, 04:28:18 pm »
Yes, I'm curious as well.... ;D ;)
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline Terry in Australia

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Re: Keilhin vs. Mikuni for 77 Honda CB 750K7.
« Reply #38 on: August 19, 2013, 02:12:25 am »
I'm still waiting too, my "supplier" in the US has promised he'll mail them out on Tuesday, so all going well I'll have them in my hot little hands in a couple of weeks.

In the meantime, you two might as well continue waffling about the intricacies of Strombergs v SU's, or whatever this thread was about........ ;D
I was feeling sorry for myself because I couldn't afford new bike boots, until I met a man with no legs.

So I said, "Hey mate, you haven't got any bike boots you don't need, do you?"

"Crazy is a very misunderstood term, it's a fine line that some of us can lean over and still keep our balance" (thanks RB550Four)

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Re: Keilhin vs. Mikuni for 77 Honda CB 750K7.
« Reply #39 on: August 19, 2013, 03:00:56 pm »
I thought we'd moved on to Webers.... ;D 8)
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline Tintop

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Re: Keilhin vs. Mikuni for 77 Honda CB 750K7.
« Reply #40 on: August 19, 2013, 03:07:53 pm »
I thought we'd moved on to Webers.... ;D 8)

No there's a whole thread for them RR. ;) :)  How about Lectrons. ;D ;D ;D ;D ;D
1977 CB550/4 Cafe - Speed Warrior / BOTM 03/11
1980 CB750F (project)
Whittaker GBF Vintage Racing Sidecar (XS750 power) - ITG / 151's / CMR Racing Products (SOLD)
1976 CB400 SS - stock / BOTM 04/11 (SOLD)
1973 CB750 K - basket case (SOLD)
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550/750 Filter Thread
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Offline Retro Rocket

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Re: Keilhin vs. Mikuni for 77 Honda CB 750K7.
« Reply #41 on: August 19, 2013, 03:30:46 pm »
I thought we'd moved on to Webers.... ;D 8)

No there's a whole thread for them RR. ;) :)  How about Lectrons. ;D ;D ;D ;D ;D

Picked up a reco'd set of VM29 smoothbores last week, will that do..?    ;D ;)
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline Tintop

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Re: Keilhin vs. Mikuni for 77 Honda CB 750K7.
« Reply #42 on: August 19, 2013, 03:46:15 pm »
Just sold a pair of VM34's.  They got ditched for the Weber. ;) :)
1977 CB550/4 Cafe - Speed Warrior / BOTM 03/11
1980 CB750F (project)
Whittaker GBF Vintage Racing Sidecar (XS750 power) - ITG / 151's / CMR Racing Products (SOLD)
1976 CB400 SS - stock / BOTM 04/11 (SOLD)
1973 CB750 K - basket case (SOLD)
77 CB550 Cafe build
550/750 Filter Thread
Sidecar Rebuild Thread

Offline Retro Rocket

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Re: Keilhin vs. Mikuni for 77 Honda CB 750K7.
« Reply #43 on: August 19, 2013, 03:49:26 pm »
Just sold a pair of VM34's.  They got ditched for the Weber. ;) :)

Are the VM34's smoothbores..?
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline Tintop

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Re: Keilhin vs. Mikuni for 77 Honda CB 750K7.
« Reply #44 on: August 19, 2013, 05:54:15 pm »
Just sold a pair of VM34's.  They got ditched for the Weber. ;) :)

Are the VM34's smoothbores..?

Round slides, common stuff on snowmobiles.  Some guy on fleabay wants $300 for a pair 'jetted for XS650'. ::)
1977 CB550/4 Cafe - Speed Warrior / BOTM 03/11
1980 CB750F (project)
Whittaker GBF Vintage Racing Sidecar (XS750 power) - ITG / 151's / CMR Racing Products (SOLD)
1976 CB400 SS - stock / BOTM 04/11 (SOLD)
1973 CB750 K - basket case (SOLD)
77 CB550 Cafe build
550/750 Filter Thread
Sidecar Rebuild Thread

Offline Don R

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Re: Keilhin vs. Mikuni for 77 Honda CB 750K7.
« Reply #45 on: August 19, 2013, 07:31:33 pm »
Lectrons are great for WOT.  I ran one on methanol on a briggs.
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Offline scottly

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Re: Keilhin vs. Mikuni for 77 Honda CB 750K7.
« Reply #46 on: August 19, 2013, 08:25:16 pm »
As has been said before mate, both carb choices you've mentioned will be horrible on a stock, or near stock CB750. Wait a couple of weeks and I'll post some pics of another carb option for CB750's that will work well on stock or mildly modified engines. Cheers, Terry. ;D

Ya wouldn't be thinking of a set of CV's from a CBX would ya Tez?

Ha ha, no Brian, although the 32mm CV's on my gold bike worked very well. ;D
You aren't thinking of the single carb set-up, are you??
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No Scott, I wrote the POS-A carb setup off as a bad joke, but there's something else on the horizon that'll work well on stock, or near stock CB750's. More soon. Cheers, Terry. ;D
I was actually thinking more of the new Mikuni single carb system developed by a member, rather than the old Posa-leak or Leaktron carbs. ;D
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Offline Terry in Australia

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Re: Keilhin vs. Mikuni for 77 Honda CB 750K7.
« Reply #47 on: August 20, 2013, 12:25:14 am »
I had a Lectron carb on my Yamaha XT500, and with the Peter Allen (not the poofy singer) exhaust, it went wicked fast. Didn't leak either, is that a problem with Lectrons? I've seen a few sets of Lectrons for CB750's and Kawa Z1's on eBay, but they seem to go for big bucks? Cheers, Terry. ;D
I was feeling sorry for myself because I couldn't afford new bike boots, until I met a man with no legs.

So I said, "Hey mate, you haven't got any bike boots you don't need, do you?"

"Crazy is a very misunderstood term, it's a fine line that some of us can lean over and still keep our balance" (thanks RB550Four)

Offline BPellerine

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Re: Keilhin vs. Mikuni for 77 Honda CB 750K7.
« Reply #48 on: August 23, 2013, 09:10:11 pm »
this bike should be bike of the year with 210 miles and no fancy stuff!!bill
1978 CB 750K ard and webers
another anfob