The day my Honda died....

[D-Mac]

Hi everyone,

I am sad to report at that 1:10pm today, my 1970 Honda CL-350 Scrambler died. Cause? Some sort of catastrophic engine failure.

I hadn't ridden it in about a year (focused on getting the new BMW prepped for the rally and such), but this morning I decided to get the Honda running again. I was thinking about selling it to make room for a different bike, but I was unsure. When I put it away last year (after one 30-mile ride), the right-side was misfiring. It looked to be a bad coil, so I was planning to order a replacement set. Unfortunately the only cheap replacement is out of stock until September due to the Japanese parts shortage, so I tinkered around instead.

Upon pulling the resistor caps of the plug wires, I discovered the wires were really loose and badly corroded! A little trimming of the wires and SPARK! YEAH! Put in a freshly-charged battery, filled the tank, checked the timing/oil/valve clearances and hit the starter.

She came to life IMMEDIATELY. YES! I got my gear and headed out.

It's taken 3 years, but the scrambler was running BETTER than new. Pulls smoothly, shifts like butter, new tires turn-in amazingly well. I took it easy and didn't rev it up too hard, but it was still an absolute HOOT. No wonder Honda sold so many CL/CB350s. They are really a great bike.

Anyway, not wanting to push it, I headed for home. As I turned the corner and came down my street the engine died. The bike jerked forward a little and kept rolling (I quickly pulled in the clutch). I coasted into my driveway.

Then smoke started rolling off the engine. I also noticed oil POURING down the outside of the cylinders. Oh oh. I thumbed the starter. Nothing. Not even a hint that the engine was thinking about turning over.

I rolled the bike into the garage and put the drain pan under it. I checked the oil and there is still plenty in there.

I'm thinking blown head gasket or perhaps a cam chain catastrophe of some sort (the latter is common on these twins). I will try and find a compression gauge later today, but I think I already know what I'm gonna find.

Now the question is......rebuild her bigger and better or part her out. A rebuild makes zero economic sense, but it might be fun. Parting her out would be logical and profitable, but I'm not sure I can bring myself to tear her apart and sell her bones over the internet. What's funny is that a neighbor saw me wheel her out and fire her up and asked "how much?" I said we'd talk when I got home. I don't think he's interested now!! The oil trail down the street and pooling in my driveway are a bad omen.

Thoughts?

[wibornz]

It is always a sad day when a bike gives up its ghost.

[bubba zanetti]

The CL 350 is a wonderful motorcycle. I love the looks and I would think a rebuild would be in order, be fun and in the end keep a classic on the road.  

[greench440]

Rebuild it.

[Pfloydgad]

I don't recal anything bad about the cam chains on just about any Honda bike. I did the sales thing in a couple of Honda dealerships a nd never saw any 350 model wht a cc gone. But, the head gasket is notrious for drying out, and pissing all over like an old Norton. If this bike is in even just decent shape, it could be an easy fix, just time and blood, and a true classic.
Good luck on your decision.
Everybody ride safe out there.
Greg

[CLAY]

As you can probably guess, I'm in the "save it" column.  These things are getting more and more rare, and they are a real head turner.  I'll be picking up a couple XS650's in a few weeks from the east side of the state with the same plans.

[Mr.Black]

 

[D-Mac]

Actually, the cam chain was prone to failing on the 350 twins. The problem is with the crappy tensioner Honda designed for these bikes. I have the last generation tensioner (a manual one - earlier ones were hydraulic), and even it isn't very good. The rubber wheels on the tensioner wear off, debris goes everywhere, chain gets loose and starts slapping around, and then the chain fails in short-order. Many seem to fail at between 10 and 20K. Mine has 10,900 miles on it.

I'm now 99.9% sure the cam chain broke. The pistons move up and down nicely (I can see them through the spark plug holes), but the cam shaft no longer spins as the engine is turned over (so no spark is generated, which makes sense because the point aren't opening and closing anymore). The valves also appear to be closed "permanently" (rockers are loose no where where the engine is turned to). That can't be good.

I'm currently draining the tank to remove it in order to finish taking the tensioner off. Once it's off, I think I should be able to see what's going on with the tensioner wheel and possibly the chain (or lack thereof). I adjusted the tensioner when I first bought the bike, and I thought there might be a little noise coming from there, but without a reference point I figured it was fine.

In any case, it's gonna need a major overhaul. I just hope the valves aren't screwed. I also don't know if the massive oil leak happened first or whether it resulted from a broken cam chain. I don't have a good feeling about it though. I suspect I may have a crack/hole somewhere in the case because the oil absolutely gushed out when the bike died. There are a lot of nooks and crannies in the head and I haven't had a chance to really look things over carefully yet.

The good news (?) is that you can now buy a trick tensioner that never fails and needs no adjustment. Of course it costs about $250 and you need to split the cases to install it.....

[Mr.Black]

The good news (?) is that you can now buy a trick tensioner that never fails and needs no adjustment. Of course it costs about $250 and you need to split the cases to install it.....

Something do keep you busy this winter?

[D-Mac]

Fooling around a little, it looks like I have the following issues.....


Broken cam chain

Bent/broken valves (I think I can see one of the intake valves when I pulled the carbs and it looks like it's broken in half!?)

Cam sprocket bolts are probably sheered off and broke the cam box (seems like a good explanation for the major oil leak)

Possibly a damaged piston(s) and valve guides.

Looks like I need a completely new top end.

[xsPain]

Think about how awesome you will feel when you fix all that and fire the bike back up next spring. And when your neighbor asks how much you can just laugh at him.

I wonder if there are complete motors on ebay...?(Which there probably are)

[VintageAmor]

Funny (not ha ha), your truly sad story    brought this song to mind:



Funny (ha ha), Paper Lace is of similar vintage.  

Anyone out there write alternative song lyrics??    "The night Mac's Honda died"

[D-Mac]

Think about how awesome you will feel when you fix all that and fire the bike back up next spring. And when your neighbor asks how much you can just laugh at him.

I wonder if there are complete motors on ebay...?(Which there probably are)

There are generally lots of motors out there. I'm pretty sure that CB350s (more common) from 1970-72 have an identical top-end as my bike, so I can probably use one of those as well.

I'm gonna take it over to my local Honda expert and see what he thinks. He rebuilt a CL350 last year so he's pretty familiar with them. If I do keep the bike I'll be tempted to do a re-bore, get new valves, new tensioner, and maybe even throw an electronic ignition setup on it. Might as well go all in or not at all I suppose. Lots of folks race CB/CL350s so there are plenty of trick parts available for them.

[D-Mac]

Cam chain DIDN'T break. I can clearly see and feel it with the tensioner off. Cam shaft doesn't move with the crank.  

Bent valves for sure and a new hole somewhere in my engine. I'm going to pull the motor and open her up for a complete diagnosis.

Complete rebuild, new engine, or part it out are my choices. I'm going to wait a week. As much as I'd like to rebuild, it'll cost more than the bike was worth when it ran well.

[veefer800canuck]

It ain't investment banking. It's a labour of love.

You cannot justify it in dollars and cents no matter which way you look at it.

Either you want a rider, or you sell a basket case.

Depends on whether the bike speaks to you or not.


If you really wanted to do it on the cheap, swapping in another whole known good used motor would be best.

[veefer800canuck]

???


http://cgi.ebay.com/ebaymotors/Honda-1972-CB350-Motor-No-Carburetor-_W0QQcmdZViewItemQQhashZitem4aad062535QQitemZ320730441013QQptZMotorcyclesQ5fPartsQ5fAccessories

[scottzilla]

Somethings not right.  Hondas don't die.

[FJRmgm]

I had a 1970 SL-350 Honda when I was a senior in high school and I and my friends rode the crap out of it for about 40k miles then I handed it down to my younger brother who rode it for several years.

At one point in our small SE Iowa town we had: two SL-350's, one CL-350, one CB-350 and one XL-350 (single cyl).

We were some bad dudes when all five of us were together.

So, for sentimental reasons I vote REBUILD!!

BTW - for a long time Honda sold more CB/CL/SL 350 motorcycles than any other models.