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hey rob
welcome and glad you spoke up on this one, your 550 has always been an inspiration. your site really looks great, tons of great info. I had never seen the mantlepiece article before. I was actually just going through the old sohc4 boards yesterday and saw your reply to a question I had about 750 carbs. you mentioned you were going to try using cb77 26mm carbs on one of your projects. did you ever get anywhere on that? I'd be interested to know because it could be an option for my 350f racebike.
 

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quote:
hey rob
welcome and glad you spoke up on this one, your 550 has always been an inspiration. your site really looks great, tons of great info. I had never seen the mantlepiece article before. I was actually just going through the old sohc4 boards yesterday and saw your reply to a question I had about 750 carbs. you mentioned you were going to try using cb77 26mm carbs on one of your projects. did you ever get anywhere on that? I'd be interested to know because it could be an option for my 350f racebike.
I have collected about 12 CB77 carb bodies (both round and square float bowl style). But, I haven't got around to trying to get them on the 550. I just haven't had the time/motivation. Last summer, I ended up putting the stock carbs on it, but with 118 (drilled 105) main jets and the needle up 1 notch. It runs great, doesn't get hot anymore and it idles like stock. I'm sure the 26's would be better for power, but also alot of work to get right.

-Rob
 

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how does the power feel compared to the bigger carbs? I eventually want to put that bored 550 motor together as another racebike project. I know someone who made a set out of 25mm Amals bored to 26mm for a 350 four racebike and your comments about the cb77 carbs got me to thinking. are those cable actuated or do they have some other linkage setup?
 

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quote:
how does the power feel compared to the bigger carbs? I eventually want to put that bored 550 motor together as another racebike project. I know someone who made a set out of 25mm Amals bored to 26mm for a 350 four racebike and your comments about the cb77 carbs got me to thinking. are those cable actuated or do they have some other linkage setup?
The power actually feels better with the stock carbs, but I'm sure that's only because I never got the 750 carbs tuned properly. If I'd taken the time to really set them up, I know they would work better. I really don't even know why they wouldn't idle. If you think about it, all of the early Keihin's used a 25mm slide, and a 22mm bore. The throat was enlarged by having an oval shaped throat. The 550's used a round bore, the 26's a slightly oval bore, the 750's a bigger oval. So, the opening area at idle shouldn't have been any bigger with the 750 carbs. I think it must be the difference in the throttle slide cutaway that was giving me trouble. Unfortunately, the 550 slides won't work in the 750 carbs without mods. When I build my next 650 headed motor, I will probably use the 28's from a 750 again. (And try harder to make them work...)

The CB77 carbs are cable actuated. No linkage like the 550 setup. I would think they would adapt pretty easily on a CB350 twin.
 

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Rob,
Is there a pilot jet or an air idle circuit?

Aaron
On the 750 carbs? Yes, both. Unfortunately, the smallest pilot jet available is a 35, which is what I had. The idle air screws had very little effect, from what I could tell. I think I started them at 1 turn out or something like that.

The CB77 carbs are very similar to the CB750 carbs. They use the same style jets as the 750 carbs, and also have an air cicuit.
 

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I think we used 25's (I think actually 22 that where drilled) from another bike using Keihn's, then I believe the idle circuit will do something for you. I do remember not be able to get the 35's to idle well no matter how much time spent. You have the yellow 550four... right? And also great website, the layout goes well with Honda stuff.

Aaron
 

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Hey jc
->the ones i have wont fit your bike.


jc
What size clip on's are they - I might have a use for them
PB

76 GL 1000
72 CB350 Racer
84 RZ 350
(and a few more)
 

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pb, they are for stock 350 honda tubes, so 33mm. i have the clamps from proflo, i want the bars though for race spares. the bars they sell for 20 bucks i think??? or maybe its 10. i dont remember. i used them for one season. if you want em, i'd work out a trade for some parts im looking for if you have em. they are the ones almost everyone uses. they are 2 piece, and bolt together around the tubes, so no pulling the top clamp or dropping the tubes.



later
me
 

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This 550 performance web sit is very good. I have been in the stages of useing the 1978 650 head in my 550. I cc'd the cumbustion chamber and it is a cool 27 cc's. But like he said the studs will not work they will have to be made. I am making my own and heat treating them. I am so excited for the race season next year. My 500 last year"The Test Mule" will look like it was from the Screaming 50's I learned so much from that motor, and all of you who saw me race last season, it wasnt the motor that gave me problems.....
 

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quote:
pb, they are for stock 350 honda tubes, so 33mm. i have the clamps from proflo, i want the bars though for race spares. the bars they sell for 20 bucks i think??? or maybe its 10. i dont remember. i used them for one season. if you want em, i'd work out a trade for some parts im looking for if you have em. they are the ones almost everyone uses. they are 2 piece, and bolt together around the tubes, so no pulling the top clamp or dropping the tubes.



later
me
I can make those work,(once I open them up a little bit, and it's just a stock size tubing for the bars themselves. What are you looking for in the way of parts?
PB

76 GL 1000
72 CB350 Racer
84 RZ 350
(and a few more)
 

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pete, to open them up, you'll have to machine them. they are thick. do you know what im talking about? you can see em at pro-flo.com im pretty sure youve seen em. they take a standard size bar tube. (7/8??) steel is the best. the aluminum ones look nice but suck for track use since they bend so easily. what are you going to use them on?? got any 750 front wheel/brake parts i can use for my street fighter? either that or im on a search for v30 v45 v65 tachs. if you give me your adress, i'll mail em up to you.

later
jc
 
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