Topic: CB550K0 Build - 450T Tank mods

[streak09]

Yes sir it is. Im using harbor frieght gauges. I used them on my 360 and they worked like a charm. They may not be spot on, but they get you in the right area. The engine will noticeably increase in RMP when you hit that sweet spot anyways. Thats my reasoning for being cheap 

[DustyRags]

Hey, cheap is as cheap does. I got mine from the gardening section of Ace Hardware!



Seriously though, just a thought- you might want to get it all synched, swap the tubes around and hit it again, just to verify that you're actually synced, and not that you're just getting the same display on the needles. Mind you, I'm just saying that because I've heard iffy things about HF, and not because I have any experience with their gauges.

Also- if you've never synced those things before, let me warn you that it's a bit of a pain. I found it works best if you get the lock nuts on the mix screws just barely loose. Basically, you're making minute adjustments up and down- if the lock nut is loose enough that the whole thing moves up and down when you touch it with a screw driver, you'll go nuts. Loosen them just enough that you can turn the screws through the friction, and that'll get minimized. Once I figure that out, it got lots easier. Good luck!

[streak09]

Yes sir it is. Im going to be using cheapo harbor freight vacum gauges. Ive used them on my CB360 and they worked well. I do have a question while on this topic though. Can I use two gauges to sync all four carbs? I know Ive read that you can sync some bikes with only two gauges because the carbs are adjusted in pairs. I dont think this is so on the 550 though? Also, seems like every shop manual out there is convieniently missing the carb sync and adjustment pages  . Anybody have access to those?

[streak09]

Sorry bout that double post thing... thought my post didnt go through so I posted again

[DustyRags]

I've heard you can, but given how finicky it seemed to be, I'd hate to. I adjusted mine all together. Just make your own manometer- I think mine ran less than $5 for some clear tubing, a couple of connectors, a bit of board, some wire and a quarter cup of motor oil.

Oh, yeah, and you can find the manual on this site. Check here: http://www.sohc4.net/cb550books/

[streak09]

Oh, yeah, and you can find the manual on this site. Check here: http://www.sohc4.net/cb550books/

Its missing the same pages also... 

I may make a manometer like yours, looks pretty simple.

Anybody else have any leads on the missing pages?

[DustyRags]

Bummer. Check on Amazon or something for a Clymer manual. I used both when I got my 550 going, and the two manuals were a great compliment to each other. Seemed like whenever on got vague, the other one filled the gaps very well.

I used the info in this video. It's pretty good overall, except that you want to be syncing them at an idle, and this guy's bike is running way too fast to be on the idle circuit, so ignore that.

http://youtu.be/t0qf11BOx6o

[streak09]

Well I made some more good progress today. Finished all of the wiring under the seat, or I should say lack of seat. Haven't tackled the lights or anything though. Looks kinda like a rats nest, but it works and relatively easy to access.





The previous owner decided it was sufficient to just twist the wires together and wrap in electrical tape . So I went in and soldered and shrink wrapped all the lose stuff, and added some connectors here and there. After I got everything hooked up I tried to turn over the starter, and voila, it turned over. First time thats happened on a first try! Then I hooked up a kill switch to see if I was getting spark, yup! I was pretty excited. I think Im learning a lot about the electrical side with this build, and boy did I need it.

And if thats not enough excitement for one day, I got my package from David Silver Spares! Its like Christmas!



New booties!


By the way, DSS has the boots cheaper than anyone on ebay. Even with the overseas shipping.

Ive really tried not to get ahead of myself on this bike. I tend to rush things a bit and it ends up taking me more time in the end. Ive done pretty good so far, but I attribute that to the lack of time that I have to spend on the bike. I probably should have waited to put the carbs and airbox on, but I just couldnt resist.



Anyone who has done that before, knows that is not an easy task, so I called it a day after that... I need a beer

I still need to put the exhaust back on, then I can try to start her up. My plan is to hopefully get it running well, or at least run it enough to know what needs work. I also wanna see how loud the exhaust is and make some adjustments. After that Ill tear it back down and work on thoroughly cleaning it (i think its obvious it needs it). Im afraid its gonna need new rings, at least on the 1st cylinder. Ill get a compression tester and do some tests on it later to verify.

Ill probably start on the seat next though. I want to try my hand at making a seat pan and forming some foam. Its going to be pretty simple, along the same lines as this one.



Well, thats enough blabbing for today! If anyone has any thoughts, speak up! Its always nice to get opinions from other directions!

[Vinhead1957]

I think you would like a new fuse holder to fit nicely in the electrical station

[streak09]

Fuse holder? Do you have a smaller one in mind or something?

[streak09]

Todays weather was great so I spent a good part of the day starting and cleaning all my bikes. I also did some work on the 550. I slapped the headers on with some new crush gaskets and installed the battery and tank. After that I checked for spark and made sure nothing was gonna catch on fire. Second kick and it fired right off! It actually took me by surprise. It was idling high, im assuming from my bench sync, so I dialed it down with the idle screw and to me it sounds pretty darn good.

There is one problem though. The far left cylinder (I think #1) is popping and spitting. It definitely isnt getting as hot as the other 3, but it is getting hot so it is firing some. Could someone go through the process of tuning these carbs? Ive fiddled with carbs and somewhat familiar with them, but really struggle to find a methodology to get them to where they need to be. I really dont have any experience with four carbs either, ive pretty much only worked on singles. If anyone could help me out a little bit i would appreciate it! I probably should get some compression readings on the cylinders. I also have some vacuum adapters so I can do a sync too. Anyone know of a good write up?


Ignore the fugly seat 


Heres a little vid of it running

[RAFster122s]

Without an exhaust you don't have much back pressure and therefore you are likely to be running lean and transitions on throttle will be rough because of the vac not being there...

[streak09]

Yea, I know its not ideal, but its kinda where I stand now. Do you think that could be the cause of the popping? I didnt really think that was the cause because the #1 cylinder was the only one doing that. I would love to get a 4 into 1 exhaust on it, but cant right now... money just puts a damper on everything 

[DustyRags]

If it's bench synced, and the other three are running fine, I'm not convinced a sync is what you need. Pull the plug and check it.

[streak09]

Well I did some poking around today. I finally broke down and bought a compression tester and took some readings. Far left cylinder has about 30 psi  . Far right is 120. I can live with 120, but 30 is just down right sad. I tried the oil trick, and it only raised about 5-10 psi. Maybe I should check the tappets?

I checked the charging system too. At idle im getting 11.65 volts. Also not good. When I raise the rpms, the voltage does raise, but only to 11.75 or so. Im going to try to adjust the regulator, but I dont know if thats where the problem is. Any tips? How can I test the output of the stator?

Appreciate any tips/thoughts!

[DustyRags]

These bikes do tend to drain the battery at idle, so that may not be an issue. The higher rev output should be about 14 or so, IIRC. That'll want looking into.

You could try the tappets, certainly won't hurt. Get those all adjusted correctly, shouldn't take too long- you'll want feeler gauges, a small wrench (8 mm, IIRC) and a small slotted screwdriver. Then be sure to torque the tappet covers to the proper tension- it's something like 5 f-lbs, not much. If you overdo it, you'll wreck 'em- I did. Unfortunately, I suspect you've got a bad piston and will need to have it bored and get new rings in there at the very least.

[streak09]

Thanks dusty. Ill probably get a new regulator and see where that leaves me after install. As for the low compression... I adjusted the tappets and not much of a change unfortunately. I know im gonna get some flack for this, but I may just run it as is for now. I really dont have the money to do a tear down right now. Ill get everything adjusted right and get the bike running good (other than the one cylinder..) and ride it around town a bit. Maybe in the future I can tear it down and do it the right way. Im just not in the position to do it right now. Besides, this is by far the most powerful bike ive ridden/had so I dont really know the difference 

[DustyRags]

It's your call, but think about it this way: one of the important things to do to get a bike running smoothly is syncing the carbs. If the carbs are in sync, each cylinder contributes 1/4th of the power- think about it as four people pushing a car down the road. Each one comes up, gives it a shove, and lets the next guy in. If each one shoves the car the same amount, the car moves relatively smoothly and each person does the same amount of work. If one person doesn't shove at all, the car jolts and one person has to shove the car extra hard to get it back up to speed after their buddy slacked out.

In the case of the engine, this means that the entire gear train is going to start clacking back and forth. First fire: the engine pushes the gears; second fire: the engine pushes the gears; third fire: nothing happens, the bike starts pushing the gears, and they slam into each other; fourth fire: the engine pushes the gears again, the bike surges forward, and the gears slam back the other way. The "clonk clonk clonk" in your video is exactly that happening.

Can you ride it this way? Sure. Is it good for your engine? Oh, hell no! You're massively increasing the wear on your transmission, to say the very least.

It's your call.

[streak09]

Very nicely put dusty. I knew that something of the sort would be going on, but that puts it in good perspective. With the position im in, and knowing how much ill be riding it (not much at all), I think I will leave it for the time being. I may try to get rid of it soon (Im starting to run out of room) to make room for something else. I mainly got it because I wanted to introduce myself into a 4 cylinder, not necessarily to ride, but tinker and not drop a whole lot of dough on. Thanks for the thoughts, exactly what I was looking for     

[DustyRags]

Cool, glad I could help Sounds like a project someone with that sort of ambition and experience would love, but that would be a serious PITA if you're not into it. I'd love to take it off you hands, but I'm way out in Cali and don't really have the room for it either. 

[streak09]

Sounds like a project someone with that sort of ambition and experience would love, but that would be a serious PITA if you're not into it.

For sure! I would love to do it, but I am not quite that experienced yet, especially with a 4. Maybe this will be the bike I get that experience on though  .

[DustyRags]

Man, do it. Seriously. I jumped into this game with virtually no mechanical experience (I'd helped my dad pull the clutch on a VW bug in highschool, and rebuilt the carb on an '82 Yamaha Townie- that's it), and with the factory manual, the Clymber manual, some elbow grease and lots and lots of help from the guys on this forum I did a complete top-end rebuild on my (former) 550. It's not that hard. You can literally use my build log as a how-to if you want. Then just measure your ring gap, and drag your cylinders to a machine shop.

You can totally do this if you want. No judgment if you decide not to, but loads of encouragement if you do

[streak09]

I think I may. I do however want to finish my 360 build before I dive into the engine on this one. I think I found a gem last night on ebay, Ill confirm later though   .

[DustyRags]

Oooh, share! 

[iron_worker]

30PSI?! 

Sounds like you probably have a valve hanging slightly open to bleed off that much compression.

I think you could probably get that much compression not running rings at all. lol

IW