Topic: MotoGPWerks Pipe CB550 (Jetting and video)

[alacrity]

I noticed one potentially incorrect bit of info a couple pages back.
I am running carpy's 4-1 on a 77 cb550k. I have the centerstand on the bike. What you lose is the stock fitting that limits the c-stand travel (so the spring would keep pulling it up into the chain ...)  What I did was fashion a small steel bar "limiter" with a rubber bumper end and affix that to one of the bolts that pinches the centerstand "axle" in place.  It took a few mins to align this properly, and now I have a c-stand and the 4-1 working.

[jonda500]

Just read this whole thread and found no mention of the needle jet?

I have a 74 550F with 627B carbs fitted. I have an aftermarket straight through muffler on an oem 4 into 1 and the standard air filter is fitted but with no lid. Bike has new fuel tap, fuel cap, points&condensers and carb boots/ manifold o-rings. Coils and caps tested ok. Air screws 1 1/8 turns out. I have removed the #40/#100 jets and fitted new oem #38/#98 pilot/main jets and fitted the needle clips to the #2 slots. With this setup my NGK D7EA plugs were very white so I have added tuning washers under the needle clips(=pos #2.5), and re-vacuum synced the carbs.

I have a miss just above idle if I don't use enough throttle/revs when taking off, and a flat spot if I use full throttle out on the freeway(hot day, engine fully warm). I tried running with the air filter removed but still boggs down when you give it full throttle at highway speed.
I have tried different air screws and settings - bike always idles and responds crisply when cold so I have ordered #35 pilots.
I have spare #95 mains which I'm thinking of trying- or #110's if that doesn't work.

I have noticed the 550F needle/needle clip/needle jet set is a different part number to the 500. These needle sets are very expensive and hard to get, would they even make a difference? What other differences are there between a 627B and a 69A carb set?

[nicks2319]

Bringing this back from the dead a bit. Just got my 550 motogpwerks 4-1 in. Having an issue removing the baffle. It seems that it doesn't come out without having to take off the name plate on the rear of the pipe. Might just be this new round he made. Anyone have any idea? Thanks!

[nicks2319]

You're correct, it doesn't. Technically, drill out the rivets holding the plate on, but leave the plate attached to the pipe. Baffle will slide out, then you can install new rivets.

The plate is glued to the pipe as well, and is of thin aluminum, so removing it wrecks it. I've dealt with this 3 times already. Its the criticism I have about his system. Everything else is really top notch in my opinion.

Damn. That sucks. I'm considering taking a dremel to the end of the rivets in hopes that I can make them small enough to wiggle the baffle out. If not, looks like i'm doing it your way :-/

Thanks for the info!

[Stev-o]

Why pull the baffle?

[nicks2319]

Why pull the baffle?

He markets it as a "removable baffle" and I want it a bit louder.

[goldarrow]

Why pull the baffle?

He markets it as a "removable baffle" and I want it a bit louder.

Well, from what I'm reading, it is removable, but he didn't make it easy for you to remove, plus he's proud of his name tag. 

And the thing isn't loud enough? Dang man.  I hope you have good ear plugs

[nicks2319]

Hah, well, I was running cut off short pipes. Those were loud as hell. Putting this 4-1 on was a dramatically lower sound level. So i'm hoping without the baffle it's in between.

[SF]

Don't use the dremel on the rivets it will heat up and burn the paint on the sticker

[nicks2319]

Got the baffle out today, thanks everyone for the help. Was an easy task once I picked up a cheap rivet tool. Surprisingly wasn't much louder without it, so i'm happy. Here's a pic of it all done:

[nicks2319]

You also removed the end cap? Any particular reason? I personally prefer the finished look and believe it does add some protection from accidental damage to the pipe.

I debated it. I put it back on and realized without the baffle in, there would be a couple millimeter lip where the end cap meets the pipe. That didn't seem desirable as far as flow is concerned. Obviously, the difference would be negligible, but my OCD is getting the better of me.

[Tews19]

One last Mother Hen... If you haven't already, wipe down your pipe on the outside, with carb cleaner, acetone, or something to remove your sweat and fingerprints from the pipe. Once it gets hot enough, it will forever tarnish that beauty.

Cal do you recommend that I do that as well?

[Tews19]

Thought I would bring this up. I found the chart on how to jet. Originally I had my setting as:

110 mains
42 slows
1 notch down from stock per manual
2.5 turns out.
Float level is stock per manual

My plugs looked great. But I had this stumble that seems to be a reoccurring theme. Well I changed the air screws to 1 the stumble wasn't as bad but my plugs are pretty black. Means I'm running rich. My buddy advised me to leave the float level stock. Which I did. I changed the air screws to 1.5 but now I have a stumble but the bike pops like madness when I go WOT then let up. It doesn't pop on WOT. Color of plugs look good on WOT which from what I read means my mains are good.

Where should I go from here? Also my 550 was bored to 605 and has Mriecks stage 2 head work and a 650 cam. Electronic ignition is spot on. Running the 069a carbs as well. One thing is for sure, I'm running rich for the most part. Minus WOT and on decel.

[Tews19]

Here is the chart I've been using.

[joeyvans]

Excellent, Thanks Tews! I'm about to start the MotoGP install on my 550 K2.

[flybox1]

At WOT, if your plugs look good, move on to needle clip position chop.
This is how i did mine for needle clip position...
Got some small strips of tape.   i put one as an alignment mark on the R control.
then I figured out where 2/3 throttle position was, and placed another alignment mark on my grip, right next to the control alignment mark.
now, when you go do your needle clip pos plug chop, all you have to do is align your marks during  the 'test'
dont forget your new set of plugs 

[Tews19]

Awesome tricks Fly! I will do that. Here is the tube I picked up. Is this how I should have it? Also how the hell can I do this with 2 and 3? Do I do each carb individually? New plugs are here also. 

[Tews19]

Also I am going to take my pipe off to adjust the fork level. Do I do the test on the center stand? Kind of hard to hold the bike and balance the clear tube.

[flybox1]

Also I am going to take my pipe off to adjust the fork level. Do I do the test on the center stand? Kind of hard to hold the bike and balance the clear tube.

tube looks good. 
IIWY, id do it w/ the carbs off the bike.    makes bowl removal/float adjustment much easier. 
you can do all bowls a the same time, or just reuse one bowl and swap it between carb bodies.

[Tews19]

Thanks Fly once again. No I think I ran into an issue. I have carbon deposits where all four pipes meet. This could seriously impede proper settings if I am thinking correctly. I think I should have none here as that would mean there is a leak/hole where the pipes become one???

[flybox1]

2 choices at this point..
work on getting a new pipe, claiming a defect there
or
tune to the decreased back pressure and live with it

..im kinda surprised these pipes arent tested for this, for what you're paying
4 drain plugs in the headers,  an air source in the end, and a quick listen. 

doesnt look like there is a merge bullet there either.  one might fill in this space to prevent back flow...

[Tews19]

I looked closely. There is a plug. Contacted Motogp, left a message and within 2 minutes he called me. Can't beat that customer service. He offered to repair it as he said it's a tiny pinhole. Which I do think it is. Or if I do not want to send back he said I could jb weld it. Yes the pipe is expensive but I will attempt the jb weld first. If it doesn't hold up I will send to get repaired. I can't believe how polite he was. Last time we talked about my order we were bickering a bit.

[flybox1]

Good to hear!  His pipes are often used and discussed on the forum.

[Tews19]

Well number 4 is low. But if I wait like 45 secs it gets higher. 1 seems low in regard to the model I was given. Do I pull all now?

How long do I wait before stopping the test and turning the fuel off? First pic is #1 second is of 4 after the same time. Third pic is #4 after about 1 min.

[flybox1]

all of them need adjustment.  fuel levels are lower than i would accept on my bike.
if the fuel level changes(rises) slowly after you start the test, you have a float valve dysfunction
as soon as you turn on the gas, it should rise and stop, right at 3mm