81-550T, need 9000 rpm

[mlinder]

I am a little surprised that it doesn't idle under 2000 rpm, I wouldn't think a pipe would make any difference at idle. Maybe someone can enlighten me why this is so.

It's not the pipe. Something else is going on.

[mlinder]

So I will back out of this conversation now as I was able to get mine up to 8000 before shifting from second to third. So I wasn't trying hard enough last week. But I do wonder why would you want to do it that way? Is it just to get out of traffic real fast? Only asking because I was sitting at 45 mph by the time I shifted and I don't really need to be doing 100 mph down the road (not that crazy yet).

The little inline 4's, especially jetted as they are from factory, do not really start making power til 6.5 grand. For spirited riding, I like to keep the engine speed between 7 and 10k rpm.

[tkent02]

Short shifting a 550 at 8,200 will put you into the next gear well below the torque peak, it probably won't pull fifth or sixth any higher, especially in headwind or up a grade, and of course depending on sprocket ratios. Shifting at 10,000 or so, it is already in the torque peak when it gets to the next gear, should be able to pull it on up.
If you want to shift at 8,200 and keep accelerating, get a bigger engine.
Or make yours a 650. :-)

[Buffalo Bill]

Some work history…

Mlinder, Here's your list with my response:

* Bad coils---------------------------------------replaced, no change
* Bad plug wires and/or boots------------------maybe, but they look good
* Ignition timing off.--------------------------- N/A 1981 has electronic
* If not electronic ignition, points are toast----N/A
* Carb Boot leaks------------------------------------I cant find any leaks

Other possible issues

* Carbs very out of synch---------------They're synched
* Bad Carb diaphragms-----------------they look good
* Low cylinder compression------------just replaced the rings
* Bad valve clearances------------------in spec
* Bad battery/ground----------------------battery is OK, and grounded
* Bad advance unit------------------------maybe, never tested
* Very clogged jets------------------------clean, microscope inspected

Haven't put a timing light on it yet, I'll try that.
Charging voltage 14-15 volts

Too much to check in a day, plus I spend most of my time working for money.
Thanks!
Bill
P.S. Have installed new intake O rings as well.

[mlinder]

Dun worry, I'm at work now, getting paid to talk to you.

Please stick a timing light on there. Check advance.
Also check plug wires and boots resistance.

What plugs are you using, out of curiosity?

(Ignition timing can still be off with elec ign. Not often, but it does happen.)

All 4 headers getting hot, right?

15v sounds a tad high...

Best of luck! If I can think of anything else, I'll post, but checking plug wires and boots (and while you're at it, you can check coil resistances too..) and checking timing and proper advance, I think you may find the culprit.

[Big T]

I'd like to shift on the torque peak at 8200 rpm as I climb through the gears. Right now there's no power gain above 7000 because it progressively misfires as the rpms climb.
I'm going to order 105 main jets today.
As you have your '80 550 CV's currently set up, can it hold an idle at 1100 rpm? Mine will die out if set below 2200 rpm.

Sounds like you have major air leaks - boots, O ring, airbox status please

Your bike should rev effortlessly to redline in the lower 4 gears

[Buffalo Bill]

I don't buy your concept…

Short shifting a 550 at 8,200 will put you into the next gear well below the torque peak, it probably won't pull fifth or sixth any higher, especially in headwind or up a grade, and of course depending on sprocket ratios. Shifting at 10,000 or so, it is already in the torque peak when it gets to the next gear, should be able to pull it on up.

Not ready to argue about your conception of the correct shift point for maximum acceleration. But it sounds like a quick way to blow an engine.
Bill

[mlinder]

Not on a bike with a 9k+ factory redline. 10k is fine, and dropping rpm for next gear to beginning of powerband is how to go fast.

[tkent02]

Not ready to argue about your conception of the correct shift point for maximum acceleration. But it sounds like a quick way to blow an engine.
Bill

No, it's a 550. Blowproof. Mine was proof of this, it withstood well over 100,0000 miles of this type of use. Even then it only leaked a bit, still ran fine. OK, it leaked a lot, but no mechanical part ever broke. It loved it.
But you have to fix the missing or jetting problem or whatever it is, running it hard in that condition would be very bad.

[Buffalo Bill]

Than we agree on my bikes need for 9000 rpm…

Thanks,
Now I know you guys understand I should feel the power climbing all the way to 9400 rpm.
Bill

[mlinder]

Yes you should.

Looking forward to seeing your findings.

[Buffalo Bill]

I finally tracked down an air leak…

Sounds like you have major air leaks - boots, O ring, airbox status please

Your bike should rev effortlessly to redline in the lower 4 gears

Yes, I found a leaky intake pipe today.
I've been hearing a little pfft sound coming from the left side, it only happens about once a minute, but I traced it down by reaching under the carb and intake pipe as I warmed the bike up and finally felt some air blowing out from a crack in the rubber.
I looked for leaks in the intake pipes when I've had the carbs off, but never found any cracks before.
$30 each, anybody got some good ones they want to sell?
Bill

[Big T]

You've found the problem - time to pungle up for the new boots

You'll be rewarded with years of trouble free riding

[tkent02]

You'll be rewarded with years of trouble free riding

Or until the next long neglected gremlin shows it's ugly head.

[Buffalo Bill]

Sam & Ella's Deli…

Or until the next long neglected gremlin shows it's ugly head.

They'll just have to take a number and wait…