Topic: 72 CB350 Build For The Wife

[Harsh]

Well here I go again.  A little history before we begin down the road.  For years I have teased the wife about getting a scooter or one of those three wheel jobs.  Mostly it was just to poke at her, but I have always hloped that she would take me up on it.  Then one day she said that if I got her something like my CB that she would.  As luck would have it I had a buddy that was wanting to get rid of two 1972 CB350's.  The price was right so I bought them.  The wife can't back out now.  It took me a while to get up to PA to pick them up, but I did so last weekend.

The wife is pretty excited and scared sine she has never ridden before.  I can get her through the MSF courses for free through the Navy so she will take those.

The condition of the bikes are much better than my 750 was.  I am going to focus on the burgundy one since it is in better condition and I know it ran a couple years ago.  The red one I am not sure what I am going to do with it yet.  Right now it is a parts bike, but hopefully I can either fix it up for the boy or fix it up enough to sell.

On with the build.  This is the starting platform.



and the parts bike



Since I know it ran a couple years back I wanted to see if I could get it started and running before I tear everything down.  The bike kicked over just fine and seemed to have compression based on the sound coming from the exhaust.  I checked the petcock bowl and screen and they looked nice and clean so I put some fuel in the tank.  Opened the petcock and then cracked open the float bowl drain screws.  I allowed gas to flow until it came out clean.  Since fuel was getting to the carbs I hoped that it was getting through the carbs.  The spark plugs look damn near brand new. 

I don't have a battery for it yet so I used the one from my truck.  Hooked everything up, but got nothing but a tail light.  Absolutely nothing happened when I thumbed the starter.  I looked around a bit and found a couple of wires just twisted together underneath some electrical tape.  The wiring diagram shows that there should be a 15amp fuse there.  I happened to have a single ATC blade fuse holder in my electrical parts bin so I temporarily used wire nuts to hold things together.  Tried it again knowing nothing would  happen and I was correct.  Looked around some more and didn't see anything glaringly wrong so I decided to jump the solenoid.  The bike started to turn over.  Unfortunately, no matter what I did I couldn't get it to do anything other than turn over.  It never even attempted to start.

The weather is turning to crap so I decided to put everything away.  I guess tomorrow I will try and pull the plugs to see if they are firing.  If they are all I guess is left is that the crabs aren't providing fuel.

Hello tomorrow:  It bothered me that no lights other than the tail light come on.  So I wondered if the ignition switch and or the handlebar switch are routing power through them.  Or if the starter solenoid is routing power off of the additional leads.  Only having the tail light on had me scratching my head until I realized I must have turned the key past the run position into the park position.  Sure enough that is what I had done, but it didn't help the no start condition.  I checked the wiring and I had continuity and subsequently power where needed.  I decided to pull the plugs and check for spark.  Right side check.  Left side...Houston we have a problem.  I got spark, but it looked like the plug had never been used.  It looked brand new.  It was then I realized there was something wrong with the left side carb or fuel delivery.

I checked for fuel flow to that carb again and I wasn't getting any.  I scratched my head a bit since I got some yesterday.  I decided to check the other carb and I wasn't getting any out of that carb either.  Just to try things I switched the petcock from normal to reserve.  At that point I only got flow out of the right side fuel line.  I looked in the tank and sure enough the supply tube was not there so I was only getting fuel in the reserve position which only feeds the right carb.  Hooked everything back up, switched the petcock to reserve, and within a few seconds she roared to life.  Only running on one cylinder, but she did so beautifully.

Now that I know it will run I will commence with the tear down.  Let the fun begin.

[MoMo]

two things to check out:  carb diaphragms and cam tensioner roller.  Diaphragms have a tendency to dry rot and the tensioners disintegrate-at least those are the problems I incurred with the last two 350s I redid...Larry

[70CB750]

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[Harsh]

I don't think I am going to rebuild this one to the extent I did my 750, but it will be thoroughly gone through and new paint.  The wife does not like the color and it is obvious it was painted while the parts were still on the bike.  There is overspray in a number of places.  Hopefully this one won't take me nearly as long.  I would like to have it done and her comfortable riding it intime for my trip to Deals Gap in June of 2015.  That gives me less than a year to get everything done.  This bike is in much better condition than my 750 was so hopefully it will be easier.

[Harsh]

Johnie...only one of the bikes had a tool kit and it isn't 100% complete.  A quick look revealed that the spark plug wrench was missing.

[SOHC4 Cafe Racer Fan]

Sounds like a great project. Those 350s are perfect learn ears bikes - lightweight and manageable.

[MoMo]

I have most of a spare motor if you need any motor parts...Larry

[Harsh]

Thanks for offer Larry.  I may have to take you up on that especially for the second one.

[Harsh]

I know I said that since I had it running I was going to start the tear down, but I wanted to figure out the issue as to why the left side doesn't run first in the hopes it will stave off any issues when I put everything back together.  I took the petcock out and found that only one of the tubes was there.  The reserve tube/screen was gone but was allowing flow even though there was a lot of crud built up around it.  The main tube was clogged which obviously didn't allow fuel to flow.  I cleaned everything out, but decided to pull the petcock out of the other bike since I could see it had both tubes.  Cleaned that one just to be on the safe side and installed it.  I now had fuel flowing evenly through and to both carbs.

Started the bike but the left side still didn't work.  Checked for spark again just to make sure nothing strange happened and that was good to go.  So I guess tomorrow I will drop the bowl and check to see if I get flwo through the float valve.  In the meantime I will be reading up tonight in the manual on how to take apart the carb so I can check and make sure nothing is clogged and that the everything else is working as it should.  There were some carb parts in the box of spare parts Mags provided so hopefully I can get away with just using those, but I suspect that the diaphragm (not in the spare parts) might be dry rotted.

[rtbmrgl]

Sounds like a great project. Those 350s are perfect learn ears bikes - lightweight and manageable.

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Boy times have changed, a learner bike way back when would be a 50-100cc, you where bad a#@ if you had a 305, stripped for dirt of coarse.

[Harsh]

My first bike was an Indian 100 enduro.  That thing did not like to start.

So I dropped the bowl on the left side then turned on the petcock.  Fuel flowed out of the float valve, but it wasn't as fast as I thought it should have.  However, unsure as to how fast it should flow I thought it was good.  At first fuel was very limited coming out so thought that maybe it was just a little clogged and that everything would be good do go so I put the bowl back on.  I took off the bowl drain screw so I could visually see if the bowl was filling up.  Cracked open the petcock and nothing.  A big fat plate of nothing.

I took the bowl back off and took a good look at the float valve and float level tang.  There wasn't very much movement of the valve from fully open to fully closed.  Just a tiny bit of movement of the float caused the flow to stop.  I decided to adjust the tang a little bit to see if that made a difference.  Well it made a world of difference.  Flow increased a lot and it took a bit more movement of the float before fuel stopped flowing.  I buttoned everything up and gave it another whirl.  When I opened the petcock I could hear the fuel flowing into the bowl.

I decided to see what happened when I started it.  The bike roared to life and I could see some white smoke coming out of the left tailpipe.  The exhaust gasses were warm and the header pipe started to heat up nicely.  So I think I have that part semi licked.  the carb will obviously need to come back off so I can go through it and replace/adjust what is necessary.

So I guess NOW I can start the tear down.  I will say it may be a bit slow since I have a lot of things to do at the house.  My daughter graduates high school in a couple of weeks.  As such there will be a number of people at the house so I have a pretty good hunny do list.

[Harsh]

Well it looks like progress might be a bit slower than I had originally hoped for.  It seems my neck issues have creeped up again.  If anyone remembers I had issues during my 750 build with my neck and posted pics of the x-rays.  Well it now looks like they want to do surgery for a multi level herniation.  The doc want to remove the bad discs and replace them with some metal and plastic ones.  Oh joy.

[calj737]

Had the same option for my back. Saw a different spine specialist here in Richmond, Bruce Mathern. He advised against it as those replacements weren't approved for multi-level at the time. Was not in favor of them for single level replacement in multi situations either (something about stress to adjoining discs).

I know of no other injury that is more debilitating than nerve damage in the spine. The prospect of eating .45 slugs entered my mind more than once. Luckily, I couldn't even raise my arms to get to the damn thing.

I've since moved to acupuncture and am a lot happier. Not cured, but generally far less effected by it.

Whichever way you turn, sending you good, healthy thoughts-

[Harsh]

One of the options I am looking at is approved for multi level, Mobi-C.  I am also looking at the ProDisc-C.  I actually found a forum that is for spines.  I have been able to do a lot of reading and info gathering about what other people had done and why, isssues, suggestions, and positives.  I still need to do a decent amount more research, but I am really tired of walking around like I am on eggshells and I want the feeling back in my left arm and hand.

[grcamna2]

How's she coming along Harsh ?

[Harsh]

How's she coming along Harsh ?

Funny you should ask.

Well I guess the build begins in earnest today.  I pulled the engine.  What a pain that proved to be.  Getting the cotter pin out of the brake rod was probably the worst part.  I have no clue how I am going to get it back in when the time comes.  When I took off the cover for the front sprocket it looked like a mouse tried to make a little home in there.  I don't think it succeeded, but you could see some of the stuffing it had brought in.  When I took off the left exhaust there was a fair amount of oil inside the pipe.  I figure it was because the engine had been only running on one cylinder for a while.  The right header was an absolute pain in the arse to remove.  The collars were rusted in.  A lot of WD-40, cussing, twisting, and bumping and I finally got it to come out.
I think tomorrow I will give it a good scrub down to get rid of the grit and grime before I start taking it apart.

So this is where we stand right now.

[grcamna2]

Allright  ,are you going to start on the engine or the chassis to begin with ?

[dusterdude]

Harsh,i have an sl350 engine in a rigid frame ill let you have for free,if you want to come get it


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[Harsh]

Allright  ,are you going to start on the engine or the chassis to begin with ?

I will start on the tear down of the engine.  However, while I am waiting on parts or money for the parts I will work on the chassis.

[Harsh]

Harsh,i have an sl350 engine in a rigid frame ill let you have for free,if you want to come get it


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I might be down for that.  Is there any other info you can provide?  Feel free to PM me.

[Harsh]

Got the engine cleaned up a bit before I proceeded with the tear down.  Wow was the grit and grime thick.  I didn't really notice it last night when I took the pic, but the grime was so thick it covered half of the shift shaft.  I thought something was a bit odd when I took off the alternator cover yesterday since the screws were replaced with hex head bolts.  It didn't really dawn on me until today when I took off the points and tack covers that someone has been in the engine.  The screws that hold on the head covers were completely chewed up.  It took me a while to cut some grooves into them so that my flat head impact driver would remove them.  After I saw that I figured no one had been in the engine since they couldn't get the screws out, but I think I might have been wrong.  When I looked at the right head cover I noticed a little marring to the surface that rides against the cam shaft.  It wasn't until I got the cam shaft out that I realized the spacer was on the wrong side.  So it was either initially assembled wrong or someone along the way messed up.  However, a closer look at the head cover shows that there might have been a spacer there.  If you look in the lower right hand corner you can see a chunk of something.  I picked at a corner of it and a little piece flaked off.  I didn't notice any wear on the cam shaft though.






Here you can see how the left cylinder wasn't firing.




Head looks good.  There was lots of clean oil at the top so that is definitely a good sign.

[Harsh]

Today was a hit to the old wallet.  I purchased new steering bearings, oil seal kit, gasket kit, piston rings, cam chain tensioner, and a polished stainless steel bolt kit.

[dusterdude]

Harsh,replied to your pm,sorry i didnt see your reply in this thread,project is looking good


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[Harsh]

Well it looks like I need to get hot and heavy on the build.  I just got a call from my doc and he wants to do neck surgery on the 29th of July.  Looks like I will have two discs removed that are pinching nerves on my spinal column and replaced with this handy little device.

[SOHC4 Cafe Racer Fan]

Well it looks like I need to get hot and heavy on the build.  I just got a call from my doc and he wants to do neck surgery on the 29th of July.  Looks like I will have two discs removed that are pinching nerves on my spinal column and replaced with this handy little device.

That looks like something Devin at Cognitomoto might be able to mill you.  (Kidding)

Yikes.  Good luck going under the knife and with the recovery.  I have a couple of herniated discs that I have to go easy on.  Thankfully, no surgery required.

Do you have an estimated time of recovery?