Reviving a 1973 Honda CL350

OP
OP
MV_Dave
Joined
Nov 6, 2010
Messages
488
Location
Maple Valley, WA
Bike
2001 ST1100
STOC #
8294
I thought this might bring back some memories. It sure did for me.

Between my daughter's birthday, Thanksgiving and that pesky thing called "work", I finally had some time to start into the project. First task was a general cleaning. The good news is that there is little corrosion and the rubber and plastics are in very good condition. A bit of Mother's Back to Black on them made them look like new. The bad news is that the seat, while in great condition, smells like a cat used it for a litterbox. :cus: So its soaking in some antibacterial soap. Any tips on removing the odor would be most welcome. The bottom of the seat still has the original dealer pre-delivery inspection sticker.
IMG_0026.JPG

Everything checks out according to #8. :-D

The sissy bar is appropriate for the bike's era but I wanted a stock look so (nostalgia be damned) it was removed. I hooked up another battery to check out the electrical system. No headlight, turn signals come on but don't flash and taillight doesn't come on when the brake is applied so I've got some troubleshooting to do. The hondatwins.net forum has some good info on these bikes so I'll be doing some research there. The wiring appears to be fine so I'm guessing that I have some stuck relays somewhere. I tried some contact cleaner in the switches but no joy.

Just for grins, I decided to see if it would start so a splash of gas in the tank and hit the starter button and.... the engine turned over nicely and I got good "puh-puh" sounds from the exhast so compression is there, but the engine did not catch. I was hoping to replicate the scene out of Woody Allen's "Sleeper" where they fire up an ancient VW on the first try. It was just as well as I noticed gas leaking from several fuel lines. As I originally suspected, the fuel system will be the major area of work.

I removed the petcock and sure enough it was plugged up with old gas residue. I got most of it out manually then put it into a Pine-sol solution to soak. I had read about this on the Nighthawk forum and even about 10 minutes of soaking shows great improvement.

IMG_0030.JPG

I'll post the "after" picture tomorrow. The fuel lines disintegrated when I disconnected them. They will all be replaced. I'm hoping the carbs aren't as bad as the petcock. I'll pull the bowls off next to check how bad they are.

Also on the agenda is checking the air filters. I gently removed the right side cover but the nut holding the filter cover just spins. I need to look at the parts fiche to see what my options are.

So far it's been enjoyable digging into this bike. Plus it kept me from Black Friday shopping. :yes:. Stay tuned for another installment.
 
OP
OP
MV_Dave
Joined
Nov 6, 2010
Messages
488
Location
Maple Valley, WA
Bike
2001 ST1100
STOC #
8294
Here's another update.

I figured out why the air cleaner nut was spinning. Instead of each side having a nut to hold it one, both sides are connected via a threaded rod so in order to take one air cleaner off, both have to come off. And to take the left side cover off you have to (sadly this it true) take the exhaust pipes off. Really Mr. Honda engineer?!?! Is that the best design you could come up with??? :mad: So the bike got de-Scramblerized and the air cleaners came off. They were not dirty at all so it really wasn't necessary but at least now I know they're clean.

The petcock cleaned up nicely in the Pine-Sol dip. There's crud in the tank including some rust and my brother's attempt at using the Kreeme coating. There's a crossover hose running between the lobes of the tank that must be removed to take the tank off the bike. The hose literally disintegrated in my hands when I took it off. It felt softer than a piece of overcooked pasta.
IMG_0039.JPG
The replacement hose will be served Al Dente. I guess I found the source of the gas leak, ya think? :eek:

They say beauty is only skin deep and this bike proves it. The paint on the tank is almost perfect but the inside is a combination of flaky Kreeme coating and some rusty spots where the coating missed. I've read a lot of techniques for tank cleaning and just thought "Aw screw it!!". So in goes a box of drywall screws for some tumbling action. I had read about a brave soul who wrapped their tank and put it in their clothes dryer, thus making it a giant rock tumbler. That's a cool idea I thought so my tank got wrapped and stuffed into the dryer with enough padding that it couldn't hit the drum. An hour on air fluff mode and a lot of crap came out especially the loose coating.
IMG_0035.JPG

Next up was checking out the carbs. It's pretty easy to pull them on the CL350 so that went quickly. Supposedly the carbs were drained of gas before the bike was put away but I found that not be the case. The bowls looked they had been used to cook maple syrup. :cry: Kids, this is what happens when you leave gas in from the Carter administration.

IMG_0037.JPGIMG_0038.JPG

Into the Pine-Sol they go. Plenty of cleaning in my future methinks.

Stay tuned for the next episode: The Return of the Carburetors. :-D
 
Joined
May 28, 2011
Messages
399
Location
Puyallup, WA
Bike
05 ST1300
STOC #
8563
Hey MVDave, looks like you found something to do over the winter months. One can only imagine the Christmas list that Santa will get when you get your picture taken with him this year!:D

Can't say that I will be having the same kinda fun though. Vicki broke her wrist so I'm learning makeup and hair artistry.:eek:: Well, not really, but this is going to be interesting.

Looking forward to seeing those carbs shiny and new.
 
Joined
Feb 5, 2005
Messages
8,538
Age
77
Location
Kingman, Arizona
Bike
2000 ST1100 ABS TCS
STOC #
004
I think I've mentioned this in other threads, but my ol' Independent mechanic told me they used to throw these bikes in the dumpster after taking them (for minimal $$) on trade. :D

Good luck with the refurb.
 
OP
OP
MV_Dave
Joined
Nov 6, 2010
Messages
488
Location
Maple Valley, WA
Bike
2001 ST1100
STOC #
8294
Hey George,

Go check that dumpster and see if they're still there. Maybe there's some good spare parts in there. :-D
 
OP
OP
MV_Dave
Joined
Nov 6, 2010
Messages
488
Location
Maple Valley, WA
Bike
2001 ST1100
STOC #
8294
Well instead of "The Return of the Carburetors" maybe it should be "Revenge of the Carburetors".

So the carbs came out of the Pine-Sol soak looking light years better. A little toothbrush and Q-tip work and they look pretty good.

IMG_0041.JPG

That's the good news. The bad news is that while I was cleaning one of the floats I could smell old funky gas and could hear a sloshing sound when I shook it. I used a magnifying glass to discover a few pinholes. :mad: First to get the old gas out I used a tip from the Hondatwins.net forum and submerged the offending float in a bowl of hot water, pinhole side down. The heat from the water expands the air in the float and forces the gas out of the hole. Rinse and repeat until the float is empty. Then clean and solder the holes until no bubbles appear when submerged. When I finished, it wasn't pretty but it tested as intact. Now I can add "Float solderer" to my resume. :-D

IMG_0040.JPG

Next up was to remove and clean the jets and nozzles. The jets came out easily and I hit the nozzles with PB-Blaster and let it sit overnight. Unfortunately when I tried to unscrew the main nozzles the slot just sheared off. :censored I think my only option at this point is try to drill it and use an extractor without tearing up the soft metal of the carb body. This is a skill I was hoping to avoid adding to my resume.:doh1:I'll likely end up getting a complete jet kit and replace all of them if I can get them out. Unfortunately the CL350 jet kits are out of stock until January. Oh well, there's always the tank to work on...

Hopefully the next installment will have some good nozzle news. :-D
 
OP
OP
MV_Dave
Joined
Nov 6, 2010
Messages
488
Location
Maple Valley, WA
Bike
2001 ST1100
STOC #
8294
Nozzle News Flash!!!

I am an idiot. Or at least uninformed in the ways of carburetors. Despite having a slot just begging for a screwdriver to turn them, the nozzles are just pressed in. :doh1: After a bit more reading on the hondatwins forums, the trick is to just push them out from the slide side with something that won't deform the nozzle. They recommend using a wooden chopstick, which seems appropriate for a Japanese bike. :-D

So now two of the nozzles are out of the left carb which is good enough for tonight. Will try to finish the rest tomorrow.

So "nozzle driller/extractor" stays off the resume and "chopstick nozzle surgeon" gets added. :-D
 
OP
OP
MV_Dave
Joined
Nov 6, 2010
Messages
488
Location
Maple Valley, WA
Bike
2001 ST1100
STOC #
8294
Here's another update.

Carbs are clean and I am just waiting on new gaskets for all the jets. The rubber o-rings were pretty hard so new ones are on the way.

To remove the rust in the tank, I've plugged the petcock and crossover holes and filled it with vinegar. The acid should dissolve the rust, or at least that's the theory. If that doesn't work I'm going to try an electrolysis process. My motto is "If plain chemistry doesn't work, try electochemistry!" :-D I've read about people using that process and I've always wanted to try it.

I discovered that that vent in the gas cap was completely plugged with the Kreeme coating so that got cleaned up. It had also coated the sealing gasket on the cap so is being replaced. So as soon as those parts are delivered the fuel delivery system should be ready.

Another job was tackling the electrical gremlins. First up was going through all the bullet connectors and cleaning the contact surfaces. Then the same with the light sockets and flasher relay. With a new battery installed I now have working turn signals.:woo A closer examination of the headlight shows the low beam filament is broken but the high beam works. Replacement headlamps for that vintage, 25/35 watt sealed beam, can be found on Ebay but are $40-$50. My plan is to leave it alone for now and investigate a more modern lighting system that would keep the stock look. The electrical systems on these bikes are very marginal so a higher wattage light is not advisable.

A bit of adjustment of the rear brake sensor is what it took to get the brake light to come on. The front is going to be more work as there is a broken wire in the sensor on the brake handle. Getting the sensor switch out to repair the wire means getting the right handlebar switch assembly apart and of course the screw heads (JIS standard) are all stripped out :cus: which turns a 5 minute job into a couple of hours. Just the thing for these long winter nights.

On a brighter note, the chrome is now shiny (See what I did there. :-D) and cosmetically the bike is looking good. So when I get the fuel system parts we'll see the Scrambler comes to life.

Stay tuned...
 
Joined
May 28, 2011
Messages
399
Location
Puyallup, WA
Bike
05 ST1300
STOC #
8563
Good stuff MVD! Been wondering how your progress on this project has been going and if you've been out riding it yet. Keep up the good work, a couple pictures now and again would be nice to see what your up against. Good to know someone can get off the couch this time of year.
 
OP
OP
MV_Dave
Joined
Nov 6, 2010
Messages
488
Location
Maple Valley, WA
Bike
2001 ST1100
STOC #
8294
Time for another update. This episode is named "Better Living Through Electrochemistry". :-D

I let the gas tank sink in vinegar for nearly two week and it only helped marginally. There was some rust dissolved but there was still a lot left in the tank. So it was time to throw some electrons at the problem.

There's plenty of info about the electrolysis process out on the net but the general idea is to reverse the chemical reaction that created the rust by applying voltage. So with memories of oxidation/reduction reactions from college chemistry filling my head, I filled the tank with a washing soda solution as the electrolyte and fashioned some scrap metal as an electrode to go into the tank (but not touch the tank as that would cause a short). Then I hooked up my battery charger to provide the 12 volts for the reaction and sat back to watch the magic happen. Except it didn't. :confused:

IMG_0045.JPG

The charger didn't detect enough resistance so it didn't think it was connected to a battery so no 12V for you. I had to out-smart my smart charger by putting a spare car battery in the loop and then it was Bubble City! I thought I would check it after about an hour to see if anything was happening and I was shocked (not literally). The electrolyte solution had turned bright orange with dark rust colored clumps. The metal electrode was coated with globs of rust. This was after one hour:
IMG_0042.JPG

This was repeated every hour for the next four hours and each time the electrode was covered with the goopy remnants of the rust from the tank. I was very impressed with how fast and effective this process was. After about 6 hours I dumped out the electrolyte and replaced it with a fresh solution. What came out looked like pumpkin soup.
IMG_0047.JPG

I let it run overnight and by morning all the visible rust was gone from the tank. (Note to chemistry majors, yes I know that a lot of the rust was merely transformed into a different oxide but the end result is the same.) So I can scratch the tank off the to-do list. Still waiting on the carb gasket kits. :(
 
Joined
Jul 31, 2012
Messages
929
Age
63
Location
Louisiana
Bike
2019 GL1800
STOC #
8659
Perhaps take it to a good welding/fab shop and they can open tank at weld seams, remove rust and make any necessary repairs, weld the tank back together. Then you chemically treat inside of tank before sealing with a good fuel tank sealer that is compatible with ethanol fuel---whala---paint tank and be happy. I know this sounds costly but it is cheaper than a new tank which you wont find.
 
OP
OP
MV_Dave
Joined
Nov 6, 2010
Messages
488
Location
Maple Valley, WA
Bike
2001 ST1100
STOC #
8294
That's cool. Curious...what will keep it from rerusting?
It will re-rust if not sealed or kept full of gas. From what I understand of the chemistry, the electrolysis creates a different iron oxide (Fe3O4 aka magnetite) which is harder and more chemically stable that red rust (Fe2O3). So it is less prone to flaking off and clogging fuel systems but would eventually continue to rust if left exposed. After I rinsed the electrolyte out I blew out as much water as I could using the shop vac on "blow" rather than "suck" :eek: then I gave the insides a good dose of WD-40 to protect it until it gets installed and filled.

I'll be using in-line fuel filters so I will be curious to see how much crud they catch from the tank.
 

Bones

Your Humble Scribe
Joined
Dec 6, 2004
Messages
4,907
Age
60
Location
western Mass
Bike
2014 BMW R1200RT
STOC #
5575
Thanks for the explanation. I'll keep following your progress...great project bike!
 
OP
OP
MV_Dave
Joined
Nov 6, 2010
Messages
488
Location
Maple Valley, WA
Bike
2001 ST1100
STOC #
8294
Oops, I forgot to keep this thread up to date. I hope nobody has been holding their breath for the latest news on this project. :-D

Clean carbs and new fuel lines went on. New battery installed and she fired up with a bit of coaxing. She didn't want to idle at first, anything under 2000 RPM would die. I decided to try some Seafoam to see if that would help. Running it a bit over several subsequent weekends has improved the idle to the point it will idle OK at around 1100 RPM once its warm.

I cleaned and lubed the chain and did some slow speed runs around the neighborhood to check the running gear. It's on the original, i.e., 40 year old, tires thus the slow speed. Tranny shifts, brakes (front and rear drum:eek:) work and no binding in the chain so that's good.

The next area to be addressed is the higher RPM range. It revs to about 6K but won't go higher. The tach also acts flaky when revved so I don't know if its fuel or spark/timing that is limiting it. It has mechanical points so I'll have to read up on how to check and adjust them. That is not a skill on my current resume.:shrug2:

So the good news is that she runs but need some more work to troubleshoot the higher RPM issue. I still need new tires before I give her too much exercise.
 
Joined
Feb 23, 2007
Messages
1,526
Age
72
Location
Wichita, KS
Bike
'05 ST1300
STOC #
6776
Dave: I have some parts left over from the rebuild of my '73 CL350K5 (just like yours.) E-mail or PM if you need anything; I might have it.
 
Top Bottom