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CL175 cool guy build

5K views 22 replies 8 participants last post by  CarolinaBoy 
#1 · (Edited)
My name is Thomas and I live in Dallas, I work out of a little one car garage. I'm new to this forum but not to motorcycles. I picked up a lot of good information so I figured I'd share what I'm working on for those of you interested in a 1971 CL175. In the past I've built an XS650 chopper and a very fast SR500 tracker, but these days mostly focus on harleys.

I decided to build a 175 as a starter bike for my cool guy brother in brooklyn. I've spent less than $2200 all in on two titled bikes (including purchase price) to get where I'm currently at with the project. It's more or less finished aside from break in and tuning.

I found an ad on CL for 2 CLs with titles for $900 - one was ab 70% complete and the other was a basket in boxes. The seller seemed to have just lost steam with the projects, which is a bummer, because he was definitely on the right track:









I have to give a ton of credit to the seller for his elegant idea for a seatpan base. He made a lovely transition piece to cover the gap between the tank and seat as well as a nice looptail mod.
 
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#2 · (Edited)
I quickly sold the basket bike after hand picking the parts I would use and set out tearing the other apart.

Found a set of tracker bars I had kicking around in the garage and decided to run them after lopping off a few inches off the ends:







Here's a clearer pic of the seatpan detail. I added the wings, they looked cool. It was an old tank emblem.

 
#3 · (Edited)
I went ahead and pulled the front end to rebuild. I had two different sets and decided to go w the basket case front end as it had unpainted lowers and a nice polished top tree. The tubes were in much better shape too.



Tore them down for a deep cleaning and new seals. I also some preload spacers to stiffen them up:



And a quick fender tab shave and sand:





I also knocked the old ball bearing races out and replaced the steering bearings with caged timkens.

Oh, and I painted the frame. For budget purposes I used appliance epoxy. It really kicks ass:



So nice...



Original owner added the sweet rubber and painted the rims a gunmetal color. Looks good with the black:



I also painted the seatpan with the epoxy. Here it is:



Roller mode. I'll be ditching that cheesy gas tank:

 
#5 · (Edited)
Biltwell 7/8" whiskey throttle. I had Barnett make a 2-1 throttle cable for the carbs as all the aftermarket options are absolute garbage. A nice cable will eliminate so much synching headache with multiple carb motors.





Stainless loop for cable guide:



Rad little 4.75" headlight:

 
#7 · (Edited)
It's easy to mount a headlight with a small piece of 1/8" and the steering lock cylinder. Pull the guts out the cylinder, mock up your piece, weld it up, reinstall everything and the lock still works.







I also added a neutral light into the heatlight bucket:



Also, here's the tail light. It's a running and brake light in LED:

 
#9 · (Edited)
I used the stock scrambler exhaust pipes, heavily massaged.

I trimmed off all the unnecessary heat shield and mount tabs, gave the chrome finish a rough sand, and rubbed them down with boiled linseed oil:



Then I made a rear support bracket out of a shaft collar, 1/2" rod, and a mild tab:





SCRAMBLY

 
#11 · (Edited)
I moved on to wiring and engine work next.

All of the electronics are held in place with an aluminum tray. I used a simple 2 position switch, a centech AP-1 fuse block, a sealed on-off-on hi/low switch for the headlight, a sealed on-off for kill switch, a brake light switch, tag light, a green neutral indicator, starter solenoid, and a micro sealed starter button. The kill switch, headlight switch, and starter button are all hidden under the seat. I'm using stock points and condenser and an accel coil and plug wires. I am also using a Kohler reg/rec and an antigravity 4 cell lithium battery that is affixed to the underside of the electrics tray with double stick tape.









 
#13 ·
I rebuilt the carbs, here they are. I had about 4 pair and selected the best bits out of the lot and sent the bag along with the basket case bike. I suggest getting the no swell bowl gaskets; I had an overflowing carb and the cheap gasket swelled and prevented the float from moving. I added some tygon fuel line and the tank is getting an NOS petcock. Filters are cheapo pods - I had to modify the factory air box elbows to use in conjunction with these to make them work.



 
#14 · (Edited)
I had a bit of a saga with the engine. When I purchased the bikes the seller told me he thought something was up with the cylinder head. Motor was making compression so I decided to give it a whirl with a simple valve adjustment, oil change, and carb rebuild.

The motor fired but ran like dog**** and wouldn't really want to idle. I did a compression check and sure enough compression was low, at ~120 psi for both sides. I got a huge box of parts when I bought the bike, and inside was a load of gaskets and some fresh rings, so I decided to do a simple top end job and see if that would fix the trouble.

Motor apart:



Cylinder walls in good shape....stock bore. One broken fin..whatever:



Let's take a look at the head...



Exhaust valves look kinda weird....

oh.



I suppose the previous owner put the engine back together a tooth or two off because there was definitely some tag going on.

Since I had free gaskets and rings, and I didn't have the right valve spring compressor, and since the witness marks looked to be from bench roll over before the seller fixed the cam timing, I decided to take my chances and give the cylinders a light hone and rering and run it.

That did not work, motor only improved in compression numbers by about 10psi a side.
 
#15 · (Edited)
I decided to send my cylinder out for an overbore and get some 1 over pistons:





I put the motor back together, stuck it in the frame, and womp womp. SAME STORY.

Since the fresh slugs and bore didn't cure my woes, I made the right valve spring compressor tool, pulled the motor out, again, and took the head apart.

Years of gunk caked the seats. Surprisingly, the valves were not bent. The exhaust stem seals were old and hard as a rock, but the secondary guide seals are still soft and usable, which is good because they're impossible to find. I bought a spare head on ebay and used the springs and valves from that part. I lapped the valves and reassembled the head with new viton exhaust seals and put the motor back together.







That seems to have worked because it's purring now. Don't be like me guys do a leakdown test before anything. What a waste of time. Here's a video I made for my brother:



And another after first start:

 
#16 · (Edited)
Here's a little walk around vid. I started this build last summer and set it aside for a good while working on other projects - I literally got it going again last night.



I'll post up some completed pics and some vid after I heat cycle the motor.

Few more pics:

Modified the kickstarter so it isn't hanging in the wind:



Made a license plate bracket. I used a shaft collar matched to the OD of the shock so it mounts directly to the shock itself.





 
#19 ·
Nice build, personally id put the front fork brace back on ( its the strap under the front fender) and extend the exhaust (till the rear axle) and get better pods.
The brace will help with the stanchion flexing and the longer exhaust and bigger pods will allow the engine to breathe and make power ( what little the 175 makes shouldnt be choked out of it)
 
#20 ·
That, and maybe reconsider those tires if he's a beginner tooling around NYC...

And I dunno about laws in NYC (or if cops care to enforce it) but some states have laws against sideways mounted plates.

Just FYIs...
 
#21 ·
Nice build! Looks great.
 
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