Getting an old bike back on the road (blog)

Sheesh, what does your brother ride? Are you sure your bike isn't running poorly? I can't imagine anyone saying this bike was 'underpowered'. It's not a modern sport bike, but... If you pull back the throttle on mine, you better be holding on. Acceleration is insane. Did you ever do a hot compression test?

 

Actually no, I haven't. I got a 150psi on cylinder one when cold though. I have about 3-4 hours per day after work to work on it, and that's if I don't do anything around the house... Anything else I should check? I'll take a short video and post it up tomorrow if I can capture it...

 

Yellow is RICH, light blue is LEAN. You want a FAT DEEP blue flame, just between an orange and light blue. That'll help you head in the right direction.

You mentioned the compression on 1, you did test the other 3 right? Compression numbers are independent, but the spread affects your sync and tuning. It's always best to post all 4 up if you have them, knowing one doesn't give us enough info.

 

Ok, I was just completly backwards so I'm not crazy lol! For some reason I thought blue would be rich... :roll:

And I posted my cold compression numbers back on page 2.
New compression numbers:
1=150psi 2=113psi 3=142psi 4=158psi

I know 2 is low but I'll do a top end job this winter... I'll check the warm engine compression numbers tonight

 

He's a younger guy and doesn't understand what he's used to is dangerous. He had an R6 so if he isn't doing 140+ in 6 seconds before he realizes how fast he's actually going... it's not up to snuff...

 

Are you sure your valves are in spec? Those compression numbers are a bit wacky for a 550.

A healthy 550 should be making about 130psi/cyl, 135 is the specified "maximum." Normal or "standard" is 121psi. Mine make 126~128 on one bike and 130~132 on the other, engine(s) warm.

If you didn't put oil in the cylinders, what do your plugs look like? Either you're dumping fuel or you have a bad valve stem seal, you shouldn't be seeing compression in the 150's on a 550.

If you got a 150 cold then that cylinder was "wet." Could be oil or gas. Investigate. You may find your problem, and prevent a bigger one in the process.

 

Well there shouldn't have been anything in the cylinders, carbs were off and everything, new compression gauge to... But I've never done the test warmed up.

I was going to do a warm test today but the bike won't start at all now, plugs are wet and all plugs got good spark. I checked the coil resistance and the primary's were right at 2.5 ohms and the secondary were 25-26 kohms. My book says the secondary are supposed to be 11kohms but it's a seca book I believe. Those look good to you?

 

Ok, the bike push started. I took a new compression reading after it warmed up. This time I did it like you guys told me, all plugs out, throttle wide open, TCI unplugged. 1 = 135, 2 = 115, 3 = 125, 4 = 133. So looks like I'll be getting into the top end for an overhaul this fall... and yes, i checked the valves, finally got them all perfect.

I can't deal with this charging issue any longer, 12.8v a 2000 rpm now, it's getting worse. I took my new battery out and am leaving it on trickle for 24hrs. I put my old battery back in and it fired up right quick! I'm going to figure this out first before I start trying to tune the engine again.

I Checked some resistances and found the following:

Stator coil: 0.8 ohms across any of the 3 white wires (manual says it's supposed to be 0.5 ohms +- 10%)

Field coil: 7 ohms across the green and brown wires (manual says it's supposed to be 4.5 ohms, should I worry about this or is this something that's not that far off to worry about?)

Alternator brushes are still well within their wear limits. I tried following this guide: http://www.electrosport.com/media/pdf/f ... iagram.pdf and I followed "D" but I eventually got to the part where it asks me to check the 3 white wires resistances. I presume I should follow the arrow that says "You have a reading lower than 3 ohms or higher than 10 ohms" but they think that's something bad when my manual tells me that it's supposed to be that way...

And ideas or anything else I can check?

 

After cleaning more connections it started up finally... So I just checked the regulator out.

V2 Ignition on Engine off (Green/Black wires) = 0.8v (Book says anything under 1.8v is good)
V2 Ignition on Engine on = 3.6v Max (says it's supposed to gradually increase up to 9 ~ 11v but not at what RPM... I revved the motor just past 8k rpm and held for a sec to take the reading and it only went up to 3.6v)

Does this mean my regulator is bad or something else?? I also checked the 6 diodes and they all read correctly...

Now that I think about it, when I checked the Field coil it's resistance was slightly high, could that have anything to do with it? Which directions should I go?? Any electrical guys out there?