Topic: 1976 CB550 K2 First timer - Sold

[Marissa]

Congrats!!!

Can't wait to see more photos of it once it's fully road worthy.

[mscuiletti]

As i did a piss-poor job of repainting my emblems with model paint, i decided to replace them.





The bracket beneath the emblem had some rust so I applied corroseal last night and will spend time wet sanding and buffing so the tank is ready for when the new emblems arrive. The exhaust is en route, as is my new helmet, which hopefully will fit better.

[mscuiletti]

It is going to be a superb weekend. With it hadn't dropped 6 inches of snow last night.



I am a little bummed that my exhaust has welds right in the middle of the pipes which i had not seen in any pictures of motogp werks previously. I am sure it will sound and function great still, i'm just nit picky.



I also need to figure out why the arm and link are disconnecting. It's like the spring is not strong enough to keep it in place. I am referring to the ball and socket between the carb 1 arm and the holder.

[Stev-o]

WTF!  I cant believe he sent you those pipes!  I'd be calling and nicely asking why why why?

Cal you still have a set?  Yours are not welded mid pipe are they?

[mscuiletti]

Three pipes seem to be a different size, maybe so they fit inside the collector pipes. I'll try the brush tomorrow. I am excited to see how it sounds though.

[mscuiletti]

And in all fairness, of all of the many pictures I've seen of his work, I think only one had welds mid pipe. Even the photographs on their website were smooth across the front. If it's a new design great, as long as it sounds good, just don't love the pipes not having an even diameter down the front.

[mscuiletti]

Got an explanation from Chris. He's been super helpful and responsive, taking the time to explain as I'm obviously new to this all.

"These are stepped headers so they go from small to large half way down the header ,so they take twice as long as the old ones I made years ago but they have better down low power  (small part of the header ) and way better over rev & top due to the larger part of the header ...Also the collector is bigger much like a cb750 so that helps the exhaust to merge and exit the tailpipe."

[mscuiletti]

Got the replacement emblems and pipes mounted. I fabbed up a simple bracket for the tail which isn't pictured in these:





I went back over my static timing and corrected my early spark on 2 and 3, which of course made it run much better. I then did some work on the carbs:



After that, the bike is running much much better. Even the throttle response is quick. It sounds absolutely amazing now. I'll try to get a video tomorrow. I took it up and down my cul de sac and decided I better wait for my basic rider's course so I can learn good habits first. Only a few weeks and with luck, I will pass and get my endorsement, and then take this out for a ride.



Good thing it is close to being complete, as I need to get the truck into the garage for some body work.

[Stev-o]

Nice job....

[Motogpwerks]

Hi,
I changed the pipe back about 18mths-2yrs ,The reason is function .Since there is Devillic (china)  or hindle are around  nowadays I changed up the 4-1 to include a stepped header so this is the best performing pipe for a 500-550.The stepped header is flared and then seam welded (most exhaust companys just slide one into the other ) .So I have to bend two sets of headers to make one .
The collector is larger also and this is due to most guys have pod filters or a set of Cr's so its all about getting (o2) Air in ,Air used and exhaust out .
Yoshimura back in the day started stepped headers only on there factory bikes,Its all about having a smaller dia header pipe for torque (slight back pressure , helps  encourage scavenging  )  and the stepped (larger dia) for flow once your on the throttle/gas .The larger collector helps merge those gasses and sends them down the pipe .Thats the basic version .
I still make these maybe 5-10 a year,I still use American stainless and components so the cost to make these now is well over what I sell them for .I really don't have time nowadays as i m building my own production bike for the past 8mths & customer bikes  but I still like building the odd pipe for #$%* and giggles.
I will be making a new cb550/750 pipe in the next 2 mths ,last version ever  and will be a true merge collector (but alot more $)

[mscuiletti]

Hi,
I changed the pipe back about 18mths-2yrs ,The reason is function .Since there is Devillic (china)  or hindle are around  nowadays I changed up the 4-1 to include a stepped header so this is the best performing pipe for a 500-550.The stepped header is flared and then seam welded (most exhaust companys just slide one into the other ) .So I have to bend two sets of headers to make one .
The collector is larger also and this is due to most guys have pod filters or a set of Cr's so its all about getting (o2) Air in ,Air used and exhaust out .
Yoshimura back in the day started stepped headers only on there factory bikes,Its all about having a smaller dia header pipe for torque (slight back pressure , helps  encourage scavenging  )  and the stepped (larger dia) for flow once your on the throttle/gas .The larger collector helps merge those gasses and sends them down the pipe .Thats the basic version .
I still make these maybe 5-10 a year,I still use American stainless and components so the cost to make these now is well over what I sell them for .I really don't have time nowadays as i m building my own production bike for the past 8mths & customer bikes  but I still like building the odd pipe for #$%* and giggles.
I will be making a new cb550/750 pipe in the next 2 mths ,last version ever  and will be a true merge collector (but alot more $)

Get back to work Chris. I'll need pipes for my next skill builder. Thanks again for everything!

[mscuiletti]

While trying to figure out my slow releasing throttle, i broke my pricey signal.



I found the rookie mistake that i made, which was cutting the replacement throttle tube too short, leaving nearly an inch of rubber to rub against the handle bar. I fixed that today with a new throttle tube. Now it snaps quickly.

I also dealt with MotoGadget support whom told me that the signal was not fixable when i inquired if it was possible to remove the shaft. Rather than take someones word for it who likely doesn't actually use their kit, i came home to see what i could do. I put a rubber tube around the threads, tossed into my vice, and unscrewed the housing. I should be able to splice some new wire now that i removed the insulation, and use heat shrink to hold it in place.

[mscuiletti]

The gf took a quick video if anyone wants to hear. I did a compression test long ago which was fine, but is the valve ticking pretty normal or should I just run through them with a feeler gauge?

https://www.youtube.com/watch?v=IDe4Z9nwQtM

Also, apologies for the screen orientation. It's a pet peeve of mine.

[Smudgemo]

It won't take long to check, so I would definitely give it a look if you haven't already.

[mscuiletti]

It won't take long to check, so I would definitely give it a look if you haven't already.

I'll order a set of gauges today. I had read somewhere that its tight in there. Would you recommend an offset gauge to fit better?

[Smudgemo]

Actually, mine are some cheap MIC gauges that I acquired from somewhere once upon a time.  I take them apart to use for this job b/c the holder and others are heavy, and this is a very light gauge.  It's easy to mess up the reading with all the extra weight hanging around.  But they are straight and work fine.  I just give them a slight bend.  And make sure you don't have another one stuck to the one you want to use.  Almost did that by accident once..

[mscuiletti]

Actually, mine are some cheap MIC gauges that I acquired from somewhere once upon a time.  I take them apart to use for this job b/c the holder and others are heavy, and this is a very light gauge.  It's easy to mess up the reading with all the extra weight hanging around.  But they are straight and work fine.  I just give them a slight bend.  And make sure you don't have another one stuck to the one you want to use.  Almost did that by accident once..

Thanks Ryan. Assuming I will then need to sync once again. Beginner mistakes (learning experiences).... 

[SKTP]

It sounds awesome

[mscuiletti]

It sounds awesome

I think so too. I have another set of jets on the way i want to try as it is running a tad rich currently. I hope to reduce the popping on decel.

[mscuiletti]

I think so too. I have another set of jets on the way i want to try as it is running a tad rich currently. I hope to reduce the popping on decel.

Points to running lean not rich.

I love this forum. Great helpful people. Turns out I had been thinking when the choke lever was down that the butterfly valve closed off airflow. Whoops. Maybe I don't need those jets. When the choke is off/down it runs much better but idles high. Luckily a replacement throttle stop screw will arrive tomorrow. Growing pains.

[Stev-o]

I think so too. I have another set of jets on the way i want to try as it is running a tad rich currently. I hope to reduce the popping on decel.

Points to running lean not rich.

+1.   Could also be an air leak, check your carb boots.   Also check your plugs, lean is not good for a motor.

[mscuiletti]

When the choke is off/down it runs much better but idles high.

So, you either have the idle set wrong (too high), or you set the carb slides too open when bench synching them. A surging idle would be more emblematic of a vacuum leak.

I'll spend some time with it with weekend. The boots and O-rings are all new so I would hope it's not a vacuum leak as that does not sound fun to find the culprit. Thanks as always.

[mscuiletti]

I have now adjusted the needles three times, and never had it running as well. The choke had to be on to run, and once removed, any throttle would cause the bike to stop running. I went back to the third slot, and quickly realized that the timing was off. I ordered a Dynatek system as I was tired of playing with the points gap. I will get that installed soon and throw in some new plugs again.

That bike is a blast though. I have not had time to post anything because I have been enjoying it!

[mscuiletti]

I found the issue. The timing advance was seized. After a good cleaning, installing the Dyna S, and setting the timing, the bike started immediately with no issue. The throttle response is much quicker. I did some other maintenance including replacing a leaking shifter seal (it was self-oiling the chain, and my pants...) as well as tightening the chain. I meant to go for a quick ride around the  block but ended up coming home an hour later. It is a completely different bike. No more popping randomly from the carbs nor exhaust. I'll work on getting a video shortly. Of course, I found countless posts related to this all on this forum, so both only took an afternoon. What an amazing site.





I do want to move the ignition cables off of the frame and hang them like the factory wires, but the factory "hangers" were rusty and too small for the new cable. I will take a look online to see what options are available.

[DurangoCB]

Love it.  Clean and mean.  Nice detective work and I agree- these forums are a wealth of info.