73 Cl350 shoestring scrambler

[minibike69]

Picked up a 1973 cl350 last fall, got her running just in time for winter storage. lack of quality photos was holding me back from posting a thread, but if you squint real hard maybe you get the picture.

The previous owners had some great vision, coupled with less than great execution. When I got the bike it was running on one cylinder, had cool reverse cone mufflers, some gnarly red grips, a woodshop project as a speedo bracket, and brand new avons.

Work so far:
Ran 'new' wiring harness from the salvage yard
new points and condenser
timing/valves
cut rear frame/detabbed partially
Dime city seat
Vm30's - used
radio shack rectifier
finned stator cover

Work to be done:
Tie Shock Mounts together
Compact battery?
Carb tuning
Mount tail light/license plate
take real photos

Inspiration is Woody's brat tracker and Matt Machine's XS650

Fist pic is the day i got it. Last two are today in the basement of my house. (no garages in my campus neighborhood)

 

[minibike69]

New phone so some quick update pics

New Oury Grips, really class up the bike.

Also to fit the seat I cut the rear subframe. To add back structural support, my friend and I welded in a piece of tube steel to tie the shock mounts together. I then painted over with some rustoleum high performance enamel to prevent rusting. It's not an exact color match (or should I say the color is very close but the gloss differs), but it will get me through until a complete repaint.

Riding season is practically here in Wisconsin.

Things left to do before fully road Tuning ready:

Run Fuel Lines and New Petcock
Mount Fender and Brake Light
Mount and Wire Blinkers

 

[Barnburner]

The Dime City seat will look great with those grips! On a side note, did you check the tire clearance before welding the crossmember between the shock mounts? I think about 3+" of clearance is the standard.

 

[Rich Ard]

The Dime City seat will look great with those grips! On a side note, did you check the tire clearance before welding the crossmember between the shock mounts? I think about 3+" of clearance is the standard.

+1 - that's going to hit the tire, guaranteed.

 

[minibike69]

awwww dammit guys. i just measured at two and a quarter when the swing arm is at the full extension of the shocks.

here's a picture with the seat on (but not the shocks)

 

[Rich Ard]

Since you have welding equipment at your disposal - there are a couple of dudes on this board (check the selling section) who will put a frame loop together for you pretty cheap.

 

[Rich Ard]

Also - nice to see someone using real handlebars, and I'm a sucker for those grips. Keep it up man!

 

[minibike69]

A quick photo of a mock up salvaging the original hoop in a position that works with the seat (and clearance ).

 

[Coaltrain]

What bars are those?

 

[Rich Ard]

Did you save the brown seat that it came with? I bet I'm not the only one who would rock that thing.

 

[minibike69]

Pulled her out of the basement for the first time this year!

The bars are pretty much superbike or tracker bars, idk for sure they came with the bike.

I do have the original seat, It's cool and on the original pan, just not super well executed. Shoot me a PM if your interested i guess.

She fired on the second kick and started idling real high, idles real burbly with the chokes on. Checked the boots with starter fluid and they were fine, so my guess is just too small a pilot. Moved the needle clips down a notch and the idle settled down a bit but bogged around 1/4 throttle. I have 20's for pilots in the vm30s right now, going to try 25s or 30s to see if that makes her happy.

Here's some eye candy, my buddy max is the one holding the gas can.

 

[minibike69]

Put 25 pilots in, Was still idling high. I checked for air leaks in and around the carb boots. I started messing with the throttle cable and found that it wasn't allowing the slides to come all the way down. Started her up, noticeably better but still high. I checked for air leaks. Took the throttle housing apart and used a rotary tool to trim down the throttle cable in to prevent hang ups in the throttle housing. Started her up, Perfect! well maybe not perfect but definitely in a respectable idle range. Turned it off, went inside and grabbed my helmet, she started right up, idling nicely, and I rode it around the block for the first time since I tore her down. Everything went smoothly, a little boggy in the midrange but I'll cross that bridge when we come to it. Then as i pull into my driveway, clutch in, the Idle goes to shit again and is really high. I check for air leaks.

Intermittent high idle seems to me like an air leak, but damn if i cant find one using starter fluid or carb cleaner!

In related news my lights work in auxiliary mode on the key switch, but now while the key is in the On position. Time to start tracing wires...

 

[minibike69]

All Right I've tracked down the culprit to the 2 into 1 throttle cable that came with the kit. Cut it to length and soldered the ends on, filed the end to fit in the high exit dirtbike style throttle assembly I got, also lined the throttle assembly with some graphite. This thing is just a piece though. The idle on the bike is fine, and the throttle works as it should from 1/4 open and on, but the initial throttle opening and off idle response is horrible and sticky.

Any ideas on making it work better? or should I go for the "bought not built" solution and get a cable from Speedmotoco and a throttle housing from Dime City?

 

[minibike69]

It seems with continued finagling that the throttle cable might work out as is. It's not great feeling right now but it has stopped sticking, and i'm getting a cable luber to help ameliorate some of the drag.

In other news the headlight and tail light are back to functional (just loose connectors) and the slight oil weep from the stator cover has been fixed (fingers crossed on that one).

However all the tuning I did over the weekend in sub 50 degree weather is good for nought when in crested over 60 in Wisconsin today. Idles beautifully but off idle response is way too rich, tomorrow i'll move the needle clips back up a notch or two (currently second from bottom). Took a picture of the plug after it died when I opened the throttle.

 

[teazer]

Off idle is typically pilot jet/air screw setting and/or slide cutaway. Your doing a great job of trouble shooting in a logical manner, so kudos there. What slides are in at the moment? and what needles and needle jets. It may also be a needle jet that's too large. That would make it proportionately more rich at small openings than large.

 

[crazypj]

Fuel level too high, re-set floats +2mm

 

[minibike69]

Went to the engine shop of a friend of a friend (http://www.maxrpms.net/shop/index.php/) walked out with a motion pro cable designed to fit VMs on an xs650 but had the right ends i needed for the VM30s and the high exit dirtbike throttle I'm running. Put it on today, So Stoked!!! a night and day difference!!! It feels like a real bike!!! that cut to length 2 into 1 that DCC mails with the kits is a real piece of garbage!

bought some new plugs and the bike is much happier

Here's Where I am right now with the carbs, but as always with wisconsin weather, this could change this weekend (when we break 70!!)

Pilots 25
Needles 6F5 Middle Clip
Slides 2.5
Needle Jets 159 P2
Mains 150

Haven't measured the float height.

Now that all throttle sticking problems have been fixed (fourth throttle cable is the charm) some real tuning/troubleshooting can begin. Currently I'm chasing wiring gremlins through my ignition system, as one cylinder seems to not want to fire all the time (connectors, coils that are sensitive to moisture?, timing gremlins?). Since the bike was running on one cylinder when I bought it I did a compression check last fall. My notes say 150 and 170, but apparently in my wisdom I neglected to assign a value to each cylinder. Static timing has been set, advance mechanism seems to work.

Both pipes get hot, but when pulling the plug wires off one at a time (not great for the motor but a quick and dirty check) the bike thunders along with only the right cylinder, but when the right is unplugged the bike wants to die. For additional check that's a little less hard on the engine, when the choke is engaged on L cylinder there is almost no change in Idle speed, but when the R cylinder choke is engaged, the idle lopes to very low.

Any thoughts engine gurus of DTT?