New kid on the block, 1971 CT90 survivor.

[Fletcher Wayne Carter]

Hi gang, Wayne in Callahan FL 32011, next to Jacksonville FL.
Got about 10 hours into the initial clean up and sorting things out. It's Alive! runs good with a little over 12,000 miles. Here are a couple of Pic's for you, will be hitting you up for some questions as I go.
First off I'm 170 pounds but the bike will only do about 22 to 24 MPH have not checked the points yet if my memory is correct these should do about 40 MPH? I'm 63 so I remember these guys!

 

[NWMissouriCT90K1]

Hi gang, Wayne in Callahan FL 32011, next to Jacksonville FL.
Got about 10 hours into the initial clean up and sorting things out. It's Alive! runs good with a little over 12,000 miles. Here are a couple of Pic's for you, will be hitting you up for some questions as I go.
First off I'm 170 pounds but the bike will only do about 22 to 24 MPH have not checked the points yet if my memory is correct these should do about 40 MPH? I'm 63 so I remember these guys!

Welcome aboard!! Great looking machine there!!

 

[kirrbby]

That 90 looks like a nice one!
Welcome to lilHonda.

 

[b52bombardier1]

Nice looking and very clean. If it is not smoking, I will bet you that the spark advancer mechanism behind the points plate is stuck . . . rusty. But use caution here before you take it apart to clean it because there is a 50-50 chance you will put it back together wrong - spark will occur but will be 180 degrees out of phase with the combustion cycle.

Use a sharpie marker to put some orienting marks on it so that you can put it back together correctly.

Rick

 

[joel1234567]

Yeah you should be able to get 40mph out of it. Make sure your high/low gearing selector is not in the "low" setting.

 

[Clayton]

Very nice bike!!! I weigh 200 pounds and both of my CT90’s will cruse at 45 easily and both are 100% stock. Welcome to the forums and don’t be afraid to ask any questions here.

 

[-Nate]

Before anything else ;

Tune it properly beginning with a valve adjustment, then points gap and ignition timing to the "F" mark, this is critical ~ many (? most ?) use the 'T' mark, that's for Top Dead Center, not timing .

Once all that is done, remove the carby and inspect the main jet ~ msny still have the smaller # 62 or #65 main jet and it should be a #72 unless you're in the mountains .

The order in which you proceed will define how well it runs and how much you like it .

 

[Fletcher Wayne Carter]

Hi everyone! Been a long time sorting out life and projects, but I'm back to to the CT90.
Have not addresses the speed issue yet but she still fired right back up with no smoke or rattles.
Still 21 MPH in the high range and 16 in the low range.
Going to try my hand at the ignition advance with the help of a close friend that seems to be able to fix anything!
Question, the two fuel lines that go to the carb, looking at the carb from the right side, how do you know which is the "on position?" and which is the "reserve position"
One is of course higher than the other, I'm guessing the lower is reserve?
One more thing, the button along side the choke " pull above 6000 ALT?" I assume it richens the carb at high altitudes?
Thx for all the help.
Wayne

 

[-Nate]

Actually, the high altitude button leans out the mixture as there's less oxygen at higher altitudes .

You'll normally find the button won't stay out due to a weak spring .

Looking at the alternator rotor you'll see three marks :

"T" for Top Dead Center, used to set the valves and make sure the cam is properly timed when you replace the (usually worn out and stretched) timing chain .

"F" for Firing point, this is the static ignition timing mark .

Many use the "T" mark and have slightly retarded ignition timing this will make the engine so easy to start but robs power above idle .

The third timing mark is a pair of parallel hash mars, this is the full advance timing point and should be used to set the ignition timing with the engine running about 3,000 RPM .

Typically if you set the timing at idle the "F" mark will drift around a little bit, this is okay, getting the engine to idle below 700 RPM will settle it enough to adjust, when done the engine should idle when hot right at 1,000 RPM .

The next time the carby is off, take a look at the main jet, it should be at least a #70 .

I've forgotten the hose marks on the carby, I *think* the "O" mark is the reserve one .

 

[Fletcher Wayne Carter]

Actually, the high altitude button leans out the mixture as there's less oxygen at higher altitudes .

You'll normally find the button won't stay out due to a weak spring .

Looking at the alternator rotor you'll see three marks :

"T" for Top Dead Center, used to set the valves and make sure the cam is properly timed when you replace the (usually worn out and stretched) timing chain .

"F" for Firing point, this is the static ignition timing mark .

Many use the "T" mark and have slightly retarded ignition timing this will make the engine so easy to start but robs power above idle .

The third timing mark is a pair of parallel hash mars, this is the full advance timing point and should be used to set the ignition timing with the engine running about 3,000 RPM .

Typically if you set the timing at idle the "F" mark will drift around a little bit, this is okay, getting the engine to idle below 700 RPM will settle it enough to adjust, when done the engine should idle when hot right at 1,000 RPM .

The next time the carby is off, take a look at the main jet, it should be at least a #70 .

I've forgotten the hose marks on the carby, I *think* the "O" mark is the reserve one .

Hi Nate thank you for all the info, it will be put to good use.
BTW my high-altitude button stays out on its own, must have a good spring.
Talk to you soon, can't wait to get the CT up to speed!
Wayne

 

[-Nate]

Hang in there Wayne ~ that altitude valve is pretty simple, I'd dribble some light machine oil on the shaft and let it soak a bit then *gently* wiggle and work it in .

It can be taken apart but rarely fails so I'd not mess with it .

ALWAYS do the basics first then go back and re check ~ more than once I discover I've dynamically timed the ignition to the "T" mark....

 

[-Nate]

O.B.T.W. :

If the altitude knob remains out, that will reduce the power in normal operation.....