Author Topic: fmctm1sw 75 CB550K (Read 21573 times)

fmctm1sw · « **Reply #75 on:** September 04, 2011, 07:24:10 PM »

Thanks to member robmanero, I got my head gasket. I got the top end back together and (unrealistically?) expected to see an even 170 psi across the board. I got from 105 to 125 on them. I have new rings, honed cylinders lapped valves and torqued the head down exactly per the manual. Instead of panicking, I'm just going to get the carbs done and run it for a few miles and see what happens. On the bright side, all the lights and electricals work great...

fmctm1sw · « **Reply #76 on:** September 06, 2011, 06:43:02 PM »

Have spark on all four cylinders now...

RAWNOG · « **Reply #77 on:** September 07, 2011, 07:41:47 AM »

Hey, I have a basic question about the starter switch on a 76 cb550f right hand control. Will it work on my 75 cb550k wiring harness? it seems all the wires from the switch match up in the headlight bucket except theres a blk/red that i cant find. looking at the diagram, it seems the brwn/red(coming from fuse box) is the harness wire i should connect to.

?

fmctm1sw · « **Reply #78 on:** September 07, 2011, 05:54:37 PM »

Quote from: RAWNOG on September 07, 2011, 07:41:47 AM

Hey, I have a basic question about the starter switch on a 76 cb550f right hand control. Will it work on my 75 cb550k wiring harness? it seems all the wires from the switch match up in the headlight bucket except theres a blk/red that i cant find. looking at the diagram, it seems the brwn/red(coming from fuse box) is the harness wire i should connect to.?

check this thread out. A good read... http://forums.sohc4.net/index.php?topic=49551.msg825478#msg825478

RAWNOG · « **Reply #79 on:** September 07, 2011, 09:24:29 PM »

Thanks man, I have the hard wired switch that a single pole double throw. So I guess I was right about the brown/red wire being the correct female connection

fmctm1sw · « **Reply #80 on:** January 03, 2012, 11:36:44 AM »

Long time with no update. I got the carbs back on over the past weekend and the throttle cables connected. Connected the horn and put the battery in it. All electrics worked. I pulled plug #2 and replaced the cap with a straight one, for some reason the angled cap was too short to reach the plug. I kicked at it to make sure I had good spark. Then I hit the started button and the main fuse blew. The connections were corroded so I cleaned them up real good. Well, about a dozen fuses later I realized if I switched the key back off fast enough, the fuse would bend from the heat but shrink back down. After a day or so off and on of connecting and disconnecting connectors, I found the horn was causing it. I never would have thought. Connect the horn and turn the key on and you blow a fuse. Disconnect the horn and everything (else) works. Close to getting to the "start test" now but still need a clutch cable (and fuses are on the way from WHH).

fmctm1sw · « **Reply #81 on:** January 10, 2012, 11:18:52 AM »

Got my clutch cable yesterday. Been kind of off and on with this one. There was an issue that had me concerned. I was unable to turn the handlebars to full lock left and move the bike backwards. Full right was hard too. I looked at the steering stops and everything looked ok there. I ensured all the bolts on the steering stem, fender, and top clamp were tight. Everything checked out. I finally took the caliper off and that did the trick. Not sure what's going on with that but at least I know what it is. I started to worry that my frame was twisted up somehow. Oh and got the fuses too.

fmctm1sw · « **Reply #82 on:** January 16, 2012, 05:24:01 PM »

Did my headers over the weekend. Went the cheap route with high temp paint for stuff like BBQ grills. Comes out more gray than anything though.

fmctm1sw · « **Reply #83 on:** January 28, 2012, 01:53:14 PM »

Well, it's a runner. Not a very good runner at the moment but a runner no less. Pipes 3 and 4 don't seem to get as hot. I managed to get the timing spot on though.

fmctm1sw · « **Reply #84 on:** February 05, 2012, 02:07:33 PM »

Well, I made it to the end of the street today. Some issues I'll try to hammer out in the tech forum...

fmctm1sw · « **Reply #85 on:** February 12, 2012, 04:43:02 PM »

Update from today. I've been having issues with idle and hanging RPMs. I found the carbs were way out of balance and well below normal vacuum levels. I was able to get the readings equal as far as balance goes but I'm still way under normal vacuum. Idle wanders around still too but I can ride it though. I checked compression last week and had 150 or so when I checked. Low vacuum means late valve timing but can I have good compression and late valve timing at the same time? Looks like a question for next weekend...

fmctm1sw · « **Reply #86 on:** February 19, 2012, 04:29:12 PM »

I checked my cam timing today figuring all 4 carbs couldn't be leaking air. My notch was right on alignment with the cylinder head surface... with one exception. My notch pointed to the rear, the manual showed it pointed to the front. I didn't think much of it but I changed it anyway. I put the valve cover back on it and readjusted the tappets. I didn't check the vacuum but it seemed much the same. Pesky overflowing on #1. I may be on to something though. It almost seemed like it ran a little better when I shut the fuel off. Perhaps fuel level way too high? I set all those to spec though too. See tomorrow maybe..

fmctm1sw · « **Reply #87 on:** February 20, 2012, 05:55:43 PM »

Well, same old story. Hardly any vacuum. I'm confident the issue isn't in the engine proper so I'm going to concentrate on the intake path. It's a runner, sort of. I made a float level tester out of a clear tube and plastic today and took a look at 1 and 4. They looked ok but I really don't think that has anything to do with vacuum. My 650 pipes should be showing up soon, maybe a break will help me think...

LesterPiglet · « **Reply #88 on:** February 21, 2012, 10:58:43 AM »

Quote from: fmctm1sw on February 19, 2012, 04:29:12 PM

I checked my cam timing today figuring all 4 carbs couldn't be leaking air. My notch was right on alignment with the cylinder head surface... with one exception. My notch pointed to the rear, the manual showed it pointed to the front. I didn't think much of it but I changed it anyway. I put the valve cover back on it and readjusted the tappets. I didn't check the vacuum but it seemed much the same. Pesky overflowing on #1. I may be on to something though. It almost seemed like it ran a little better when I shut the fuel off. Perhaps fuel level way too high? I set all those to spec though too. See tomorrow maybe..

Your cam was 180 degrees out. I managed that once.

fmctm1sw · « **Reply #89 on:** February 21, 2012, 05:59:25 PM »

Quote from: LesterPiglet on February 21, 2012, 10:58:43 AM

Quote from: fmctm1sw on February 19, 2012, 04:29:12 PM
I checked my cam timing today figuring all 4 carbs couldn't be leaking air. My notch was right on alignment with the cylinder head surface... with one exception. My notch pointed to the rear, the manual showed it pointed to the front. I didn't think much of it but I changed it anyway. I put the valve cover back on it and readjusted the tappets. I didn't check the vacuum but it seemed much the same. Pesky overflowing on #1. I may be on to something though. It almost seemed like it ran a little better when I shut the fuel off. Perhaps fuel level way too high? I set all those to spec though too. See tomorrow maybe..
Your cam was 180 degrees out. I managed that once.

Unfortunately, it had nothing to do with the vacuum issue. Too bad.. SO close to being a rider.. $:-\$

fmctm1sw · « **Reply #90 on:** October 20, 2012, 06:23:13 PM »

$:-\$ Another "warning 180 days" on a project thread of mine. I started out on my 750 this morning and when I realized I had no compression on #1, I went back to this. I'm NOT pulling the motor again right now. After fighting around trying to start it, I decided to go back into the carbs. The gas was GREEN in two of the bowls and brown in the others. One of the bowls was even stained green. Idle jets were all blocked up too. On the bright side, when I drained the bowls into a measuring glass, they all measured the same. I dumped one back into a bowl and it was around 3/4 of the way full. I got all that sorted out and poured gas into the lines via a small funnel. It started up and after turning the mixture screws way in, it idled reliably. The exhaust is totally open and I'm trying to figure out a baffle solution for it, it's just way too loud. The inside of the tank didn't look bad but I might wash it out with simple green and hot water anyway. Hopefully I'm done chasing my tail on this one. I'll look at the tank tomorrow and maybe get the airbox put back on it and see what happens.

fmctm1sw · « **Reply #91 on:** July 13, 2013, 08:16:27 PM »

Wow... so long since I updated this. After struggling with poor running I broke down and bought carb kits for it. That was after I went through one failed POR-15 liner and got the tank sealed up. I started it today and it ran perfectly so I went around the bock once with it. I still need a couple odds and ends like that little spring that holds that air filter in place and some work on the brakes. I picked up a stock exhaust for it a while back as well. Hopefully, I'll have it legal before too long...

fmctm1sw · « **Reply #92 on:** July 29, 2013, 06:29:09 PM »

Worked on a couple loose ends today. Bolts for the swingarm pivot shaft, some tubing for carb overflows and tapped and helicoiled stripped mirror threads. I also added some standard grease fittings for the swingarm. Oh and my key for the seat latch, so that's on now. I rode it around the block a couple times, runs fantastic. I have the front caliper off now painting it. Brake fluid had chewed up the paint.

fmctm1sw · « **Reply #93 on:** November 14, 2013, 04:54:45 PM »

I started off to work with it one day and I had to go back home a drive. Once it warmed up, the idle went all over the place and it started stalling. I sat it for a few weeks and went over the easy stuff. I found the air mixture screws needed adjusted (it just started really cooling off here). I'm up around 130 miles now and my last ride was about 80 miles and it runs great. Here it is as it sits. It could use better body parts but I'm trying to make some headway on my 750.

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Author Topic: fmctm1sw 75 CB550K (Read 21573 times)