Ain't no body got time fo that.-or- I got the CB-Jeebies. A refresh on a Honda CB650 cafe-rat.

So, with 4 open projects in the works, what's a guy to do but start a 5th one. 

I sold my 'wife's' motorcycle, a 2005 ninja, last month. (she hadn't ridden it since our first child, who's 5) But I wasn't riding much either. 

So I attempted to sell this honda CB650 as well. Surprisingly, no one wants a bike listed as Leaks oil, covered in dirt, doesn't run right. 

Here is the patient.

Several years ago I chopped the rear off, put on straight pipes and cafe handlebars and murdered the paint. 

After that, I didn't ride it much since the ninja was more comfortable and fun so it languished. 

I tried to bring it back about 2 years ago but after cleaning the carbs it still wouldn't run right. Plates came off and it sat in my garage eating cheetos out of the bag and watching TV for 2 years. 

Well, ride or die as they say. I'm gonna fix it and ride it or I'm gonna fix it and sell it, or both. 

Step one is to pull those carbs.

I don't think those jets are supposed to be green...

The sad part is I probably only rode the bike 10 miles since the last time I cleaned the carbs... well that's what I get for not doing it right the first time. 

One old toothbrush, cut bristles in half, torch to melt, re-apply. 

I've cleaned 2 of the 4 carbs...ugh. and found numerous passages that I know I skipped last time, like the accelerator pump.

All of them are hopelessly clogged. 1980's carburetors do not like to be ignored...  

Might I ask what your asking for it?

With Cb’s it’s always the carbs. I have a 77 cb550 that’s been sitting for a decade and the rack is going straight into a pine sol bath 

Stampie said:

Might I ask what your asking for it?

I was asking 800-1000 when it was not running right. If I actually get it properly tuned and not leaking oil I'd hope to get close to 2k but that may or may not be feasible. Market is pretty darn low on these things. 

In reply to BirgerBuilder :

Around here a cb cafe bike goes for 3k +-, your market a lot lower than mine. 

But I like where this is going.  Pinesol does wonders but be careful, it can be aggressive. 

So first thing today, I went over to NAPA to buy a gallon of Chem-dip. Which was already annoying because I know I had a can of it already...somewhere. 

So when he said $47, I said, I'm gonna go to food lion. Pinesol is $3.00 a bottle. 

When I got home, I broke down the Carb rack. I was avoiding doing it, but, this is round two on this thing and I don't want to go at it a third time.

As you can see, someone shoved some granola in between the carbs and that vacuum T is completely dry rotted. 

Already glad I didn't try and half ass this thing just to get it done. 

A quick spray down from the can and in the bath they go. 

I started cleaning number 3 and 4 on the rack and was having a hell of a time getting the tiny holes for the accelerator pump and secondary jets clear. 

Much to my surprise and relief, after just 2-3 hours of soaking (While I hand cleaned the jets and internals) All of the internal passageways seemed to blow clear with just a little extra cleaner and some compressed air. 

They don't come out squeaky clean like they do from a chem-dip. But that's mostly exterior grime and oil. The varnish seems to have broken down and that's all that counts to me. 

So now I have 4 carbs, broken down and cleaned and in desperate need of some fresh rubber. Hopefully I can find all the pieces, and remember how they go back together...

check here they seem to have most of the odd stuff as far as carb guts and other gee gaws go.

akamcfly said:

check here they seem to have most of the odd stuff as far as carb guts and other gee gaws go.

Apparently, I've already been doing business with them. 

Didn't realize it because I ordered this stuff off of E-bay. And what did I order? 

So the carburetor chronicle is wrapped up for now.

All parts cleaned and separated, new gaskets up front, bought some new o-rings from NAPA for way too much money. 

While assembling the #2 and #3 carb first, I put a dab of gasket sealer around the bowls and 'tacked' in the gaskets. When I took them apart last week, one of them was misaligned and I wanted to prevent that from happening again. 

Clothes pins to hold them in while they dry. 

I put the #2 and #3 back on the rack... several times since I kept forgetting little things that go between them. 

There is a little vent tube that is missing from in front of the fuel rail in the above picture.

Getting the little tiny screws back into the choke butterflies, was one of the most annoying parts but by the time I got to the last one, they were going together smoothly.

Finally all back together...

And some added accessories...

#1 and #4 have some clearance issues so I'll need to get some type of short 45 degree tube most likely. I will be very happy to get rid of the stock air box though.

This is making me so excited for the CB650 I'm about to buy. Have you had any problems with the charging system that seems to plague these models?

maschinenbau said:

This is making me so excited for the CB650 I'm about to buy. Have you had any problems with the charging system that seems to plague these models?

I did actually. When I first got it, it wouldn't charge the battery and I had to replace the Stator? I think. Yeah, if I remember correctly, I replaced the rectifier first, but didn't replace the stator, then had to replace the stator and the rectifier again. 

Any way to put a dent in the air filter where they hit? Think exhaust header mods

Justjim75 said:

Any way to put a dent in the air filter where they hit? Think exhaust header mods

Maybe, but I think it would oval them too much and then the rubber boot may not stay seated. I'll likely wait til it's back together to come up with a solution to see what looks/ fits best. 

Just a thought.  Good luck

I'd skip the pod filters and stick with the stock airbox if you want function to be a thing. The engineering in those airboxes even back then were insane, and CV carbs just hate the lack of a shared chamber.

With the Carbs cleaned up and ready to go, It's on to the engine. 

Now, officially, the only thing wrong with it, is that it leaks oil.

Of course it leaks...like everywhere.

According to the forums, there are O-rings in the head gasket and after 30 years, they wear out. So, while I was hoping to just replace the valve cover seals, It's quickly turning into a full top end rebuild. 

This guy again.

First steps are easy enough.

Next, the head comes off without too much trouble. However, this little Berker was under the camshaft in one of the oil passages...

Looks like a chunk from some rubber seal that got sucked into the oil pump. Again, the engine was running fine... I didn't see any real damage to the cam or head so... moving on.

The head gaskets came apart easily, maybe too easily.

The number one cylinder had oil leaking straight into it. The spark plug was noticeably oily and it had far more burnt oil in/ around it. 

Back to the heads for now. Bought this guy for <$20, pulled all the valves out.

And straight into the parts washer...

God, you're filthy.

I stopped by TSC to try and get 'real' parts washer fluid, and they only had the water based, Krud Kutter.  

Honestly, it worked pretty well, though. I used it at full strength, and it washed the grease off straight away. A little soaking and the carbon started coming off too. 

After the first round of cleaning, I rinsed it off and decided to lap the valves. 

They looked pretty ok and just had some carbon and minor pitting in the exhaust valve. 

I didn't take any before pictures apparently.

Well, everything was going great, intake valves were quick and easy. Exhaust took just a bit more polishing, but then...

So looks like I have a bent valve...

If I remember correctly, this is also cylinder number one. So maybe, unburned fuel as well?

Question is, how did this happen? Only one bent, and very subtly, It looks like the engine has been apart before so maybe the PO hit it with a piston on reassembly? 

Man,  I thought I had done more updates on this. Well a little work has been done every week, even though it's been on the back burner.

It's gotten in the way of my other projects enough now that I want to finish it.

I was able to order just one, NOS valve and I got that installed. I also installed more than one of these bad boys. I do think the PO had some berkary going on...

There were also these dents on top of the head.

I made a super-flat aluminum block from two aluminum blocks and some polishing compound and was able to flatten that out with some fine grit wet sanding.

After that I had to wash everything all over again.

Next, I pulled the top of the block and cylinders out, the piston sleeves look nice and fresh so nothing was done to them. (They should look good, the bike only has 40k on it.)

Bottom half of the engine.

I also very nearly missed replacing these O-rings that go around the sleeves. luckily, I saw them in the re-build package and wondered where they go.

I had a hard time getting the last of the head gasket off so I employed my flat-block and some 2000 to finish the job.

Using some hose clamps, I was able to get the pistons back in the cylinders without any help. Only  mildly frustrating.

Now, after this, I placed the cylinder head on top and realized I didn't have an accurate torque wrench around...

So, it sat like that, for about three weeks. And here is where I really screwed the pooch. I had a towel over it to keep dust and debris out. However, on one occasion in particular, I was doing some metal grinding nearby and when I turned around, the engine was uncovered. Apparently, someone else in the family had walked away with the towel... So, I vacuumed it out with a crevasse tool and then used the air compressor to blow it out but... How berked am I?

The current plan is just to fill it with cheap oil, run it up to temp, dump the oil and refill once the bike is back together. I already installed the head studs, cam and timing chain before thinking clearly about how bad this could actually be.

I really don't want to pull the head, remove all the valves clean thoroughly and repeat and I sure ain't gonna do a full bottom end rebuild for a $800 bike.

So, what's the story guys, how dumb am I in all this?

I don't know how smart it is but *I* would do exactly what you're suggesting with a brief run, change oil and filter, and then do a longer change interval like 1k miles.

My friend Ron has one he went all through.  IIRC he lightly blasted the jugs and shot them with a satin silver, beautiful all round bike.  I’ll try to grt photos and info.

Dan

I love Honda CB’s of all sizes as my Dad and Uncle has CB and CL 350’s when I was a kid.  On some summer nights after dinner Dad would take me, my sister, and some of the neighborhood kids for rides around the block.  It was pretty cool!

pres589 (djronnebaum) said:

I don't know how smart it is but *I* would do exactly what you're suggesting with a brief run, change oil and filter, and then do a longer change interval like 1k miles.

That's all I needed to hear!

Watching and waiting for the victory ride and/or for sale price

Approaching Fall is a bad time to sell, but I'm also curious how the CB tax pays off for you.

maschinenbau said:

Approaching Fall is a bad time to sell, but I'm also curious how the CB tax pays off for you.

Yeah, at this point I'll probably get it going, and ride it a few times before draining all the fuel and storing it over the winter. I have a few other things like a fork rebuild and maybe the addition of an oil cooler I can do over the winter.

As i mentioned before, I got the head bolts down and the camshaft installed. I had a bit of a confusing time trying to figure out why the timing chain wouldn't mesh with the lower sprocket. Turns out it works just fine if you hold the bike upright instead of leaning it over on the kickstand.

(also, tiny piece of grass has been removed)

Next up, I washed the cylinder head and valve covers. The former of which has the rocker arms in it. I didn't want them to sit around wet after the cleaning so I fired up the convection setting on my parts drier.

Installed with the help of my apprentice this morning, though it did make him a few minutes late for Pre-K.

I torqued the bolts down using my very old, very cheap and very inaccurate torque wrench. So how can it accurately read 10 ft/lbs? Easy! you just "recalibrate it"

10 pound weight+ one pound of chain, 1 foot breaker bar and you are right there in the 9-12 ft/lbs the manual recommends. How far off is the wrench? It reads 26 at the correct setting...

I would have installed the valve covers as well but the new gaskets are a bit too small. So i added a dab of gasket sealer onto the gaskets and clamped them down to some aluminum. they should hopefully stay put when I install them now.