Bought a CT90!

Is that OEM? I've never pulled copper out of one.

Why is copper used on just about every 2-stroke I've split, whereas I've never found it in a four-stroke?
 
Yeah... the copper is OEM on the CT90.

As for the two stroke / four stroke difference, I assume it has to do with heat dissipation. Not 100% sure though.
 
Redliner said:
If you're not separating the top-end, just crack the head nuts one half-turn, then torque them back down in sequence. Then do your chain adjustment then valve adjustment, ignition timing, a/f mixture and idle setting.

These bikes define bullet-proof. Just keep it clean and it won't stop.
Click to expand...

I'll probably just do this for now, plus an oil change. Probably just gonna use the 15w-40 rotella I have on hand.

Unfortunately this year model doesn't have an external cam chain adjustment bolt.

Also this year (1969) has unique carbs that were only made this one year if I'm not mistaken.

Picking up the mounted wheels/tires from the Triumph shop after work!
 
Pull the bowl off and use the end of a red carby cleaner straw to lift the floats manually. Turn the fuel on and see if fuel drips down while you hold it shut.

Have you cleaned the float valve seat and removed the paper gasket? Show us what it looks like inside when you remove the bowl.
 
4upu8ana.jpg
ave6ehes.jpg
 
Float needle and seat are new. Float is airtight. I've set float everywhere from 20 to 24 to see if it works... Nothin doin
 
I'm sure the PO did SOMETHING stupid. I've already found a few silly things

I know he rebuilt the carb with a kit for a later model ct90, so I'm trying to figure out if that could be the issue
 
Naw man, won't get a chance to until tomorrow morning. Brought the carb home with me, left the bike

Also, the petcock is built into the bowl side, so that makes that kinda impossible
a5uhara6.jpg
 
I believe I found the culprit. This tiny O-ring was left out during the rebuild. I went through my little baggy of carb parts and found it... Hope it stops the leak come tomorrow.
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Erg. Still have a leak. I've got the thing starting on first kick though, so that's good. Just can't really ride it until I get this leak sorted.
 
Took it for a couple rides today, she handles pretty great. I switches out for 15w-40 rotella synthetic and it seems to have helped. The gunk that came out was black.

The front wheel needs balancing and the exhaust needs patching and I'm going to return it to stock jetting (PO replaced jets with ones for a 1970 and on CT90)

I can't get it to idle properly, but I've been pooting around a good bit.
 
Welp, that didn't work. I think I'll try cutting a little off the corner to give more clearance to the floats... It might be keeping it from rising fully.

I really could use a new float bowl o-ring and fuel passage o-ring as they're both kind of dry, but they're kind of expensive because these carbs weren't made very long...
 
I got it registered and insured today, and it seems the more I ride it the better the transmission behaves.

Insurance is $14 a month... Please don't hate me Canadian folk :)
 
A weird clunk and sometimes a missed gear between 1st and second, sometimes reluctant to downshift. Looking forward to splitting her open, but gotta get the 360 running first
 
Do you guys think JB weld is suitable for patching a hole in the exhaust manifold? It's about 12 inches from the exhaust port... I formed a piece of sheet metal around the pipe and JB welded that.
 
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