1971 cl100

benroloff

Member
Some of you may have seen my posts in the engine section of the forum asking for help but I thought it might be kind of fun to make a build thread too. I don’t know how much I’ll actually update it, and I’m sure most won’t really care as this won’t be a special or high cost build, but it might be cool for me to look back at one day. The bike: it’s a 71 cl100, build date of 4/70, so it already celebrated its 50th this year, which is kinda cool to me. This is my first bike, and I bought it from a friend who got it for free and didn’t know how to work on it so i got it for a whopping $20! I cleaned the points, got a new coil and some new floats, cleaned the tank with a vinegar treatment, and it now runs good enough to drive. Probably gonna do a carb rebuild here soon too. Planning on this bike being just an off roader for now as I don’t have the money to register, insure, and buy all of the gear I need as I am going off to college soon. So since I have the off road gear, for the near future I’ll just have some good (although I imagine slow and uncompetitive) fun on the trails. Thanks for looking!
 

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ridesolo

You only bear responsibility for your own actions
... and I’m sure most won’t really care as this won’t be a special or high cost build, but it might be cool for me to look back at one day.
Fear not, every build on here is special in it's own right and many aren't high cost, your bike will be interesting and anything you do might help or inspire somebody else in the future.

That's a great looking little ride you have there! Pretty good looking for a 50 year old.
 

Jimbonaut

Well-Known Member
DTT SUPPORTER
Fear not, every build on here is special in it's own right and many aren't high cost, your bike will be interesting and anything you do might help or inspire somebody else in the future.

That's a great looking little ride you have there! Pretty good looking for a 50 year old.
My thoughts exactly - you're in good company here mate
 

benroloff

Member
I appreciate everyone’s kind words and I’m super excited about this bike. I got it to a running and riding condition but there is a bog off of idle when you go full throttle. I did the carb floats, but I have yet to rebuild the carb. I’m sure the rebuild will help but I also considered a timing issue, and I came across the “governor” behind the points. The manual calls it a governor, but it looks to me like an automatic spark advancer that varies by rpm, which if it was non-functional, and it seems like it is not working (very sticky), it could cause running issues. So my question is, is it actually a automatic spark advanced or is it just a governor?
 

benroloff

Member
Yep, that's your spark advancer. If it's sticky, try cleaning and lubing it.
Thanks for confirming. I did some more research (probably should’ve done that before posting a question) and found my answer. I think I should be able to get it working again. Do you think this could cause my running issues?
 

whynot

~~~If it ain't raining, I'm riding~~{iii}?~~prost~
Welcome from Georgia......nice bike for that price.

Mine cost me a whopping 50 bux to get it home, but far more than I want to admit to get it where it is now.

Mine did that too, till I updated the rectifier.

Now, it kicks over on first try, even after sitting a coupla weeks.

Mines also a back yard fun toy for now, til I get brave enough to tag it.
 

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benroloff

Member
Welcome from Georgia......nice bike for that price.

Mine cost me a whopping 50 bux to get it home, but far more than I want to admit to get it where it is now.

Mine did that too, till I updated the rectifier.

Now, it kicks over on first try, even after sitting a coupla weeks.

Mines also a back yard fun toy for now, til I get brave enough to tag it.
That’s a great looking bike! Where’d you get that seat in kind of like that? I updated the rectifier a couple of days ago and it definitely helped
 

benroloff

Member
Thanks! Is the seat comfortable? Mine is kinda ripped I wouldn’t mind a new one and that’s a pretty cool one.
I originally didn’t like the look of the high scrambler pipe but it’s grown on me so much. Mine is not in the greatest of condition though. Big hole where the guard used to be, which I imagine is not helping the performance.
Before I got it home I was coming up with all sorts of ideas to make it look cooler, and now I love it so much the way it is I don’t think I could bear to change much! Has anyone ever tried to make custom side covers for one of these? I’m thinking of fabbing up some sheet metals ones because I’m afraid of buying plastic ones and bouncing it off of a tree
 

whynot

~~~If it ain't raining, I'm riding~~{iii}?~~prost~
Thanks! Is the seat comfortable? Mine is kinda ripped I wouldn’t mind a new one and that’s a pretty cool one.
I originally didn’t like the look of the high scrambler pipe but it’s grown on me so much. Mine is not in the greatest of condition though. Big hole where the guard used to be, which I imagine is not helping the performance.
Before I got it home I was coming up with all sorts of ideas to make it look cooler, and now I love it so much the way it is I don’t think I could bear to change much! Has anyone ever tried to make custom side covers for one of these? I’m thinking of fabbing up some sheet metals ones because I’m afraid of buying plastic ones and bouncing it off of a tree
Haven't really ridden any distance to say how comfortable.
Playing in the back yard on it is ok.
 
I'd like to see what you come up with for the side covers. Besides being different from those on the CB and SL bikes, the right side cover gets baked by the pipe a little. It's not easy to score a good used one.
 

benroloff

Member
Ok small update after carb rebuild. Bike revs out a million times better now. No bog off of idle, and it seems to just run better all together. Still a few small issues. I can’t seem to get the idle dialed in. Sometimes it idles fine with a certain screw position, other times it wants to die or just randomly idle up. I am going to chock this down as a sealing issue somewhere between carb and head causing extra air to get in sometimes and causing higher idle. I will probably pull the spacer between the head and the carb and clean the mating surfaces and if all else fails put some sealant on it, but I’d really rather not do that. Also the throttle gets stuck sometimes. Cable seems fine and I lined the throttle mech, but the slide is a little sticky in the carb body so I think sometimes it isn’t returning all the way. Not really sure how to remedy this?
On a different note does anyone know off the top of their head the operating temps for these engines. Temps around the spark plug hole, exhaust side of the head, header temp, etc?
 
Nice work!

Check for cracks on the carb insulator. I wouldn't use gasket sealer. Just cut or buy new paper gaskets (one on each side of the insulator), and tighten each side evenly when you reinstall the carb.

Also make sure the manifold surfaces aren't nicked. I think I read some people will use fine grit sandpaper on a glass plate to smooth out any surface irregularities. I haven't tried this myself.

Hopefully nothing is warped. If the slide and carb are clean, I'm not sure what else would cause the stickiness you're experiencing. Maybe someone more experienced will know.
 

whynot

~~~If it ain't raining, I'm riding~~{iii}?~~prost~
Yes, make sure you don't over tighten the carb bolts, that will make it run like crap.
 

benroloff

Member
Nice work!

Check for cracks on the carb insulator. I wouldn't use gasket sealer. Just cut or buy new paper gaskets (one on each side of the insulator), and tighten each side evenly when you reinstall the carb.
There should be a paper gasket between the carb body and the insulator? I assumed that the o-ring on the carb did all of the sealing there. I don’t recall seeing a gasket there so if there is one needed, that could definitely cause a problem
 

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