[doode]

I picked up this bike several months ago. Was over priced, but cheaper than all the others, and for good reason. Had tons of mechanical and electrical issues. The engine had been rebuilt, poorly, cylinders spray painted black, and had a head gasket leak that the PO masked with rtv. Rode it as is, but had trouble shifting out of 5th when hot. Finally the leaks got bad enough and I pulled the engine and threw another in. As luck would have it, I seized that engine a few weeks ago when the pushrod seal popped. So here we are.

Couple things I noticed:
- cam chain had been replaced, clip master link installed backwards
- kickstart spring seems to be sitting just on the edge of the case, and appears to have slipped off previously
- a deformed spacer on the rt side of the countershaft. Is this out of place? It's certainly not supposed to be bent.

That's all for now.

 

[Yendor]

In your 3rd Pic' the one with the cases still together.
You can see where the alignment PIN for the Shifter Drum Shaft Bearing end cap was not installed correctly and broke a CHHIP out of the case.

This will allow the shifter shaft to move sideways and cause all sorts of shifting problems.
That spacer may have been an attempt to fix the issue.

 

[doode]

Wow, great eye!
I wonder what other surprises I've got coming.

 

[doode]

Got my seals today. I had a set of cases living in my backyard for a couple years, and hosed down the upper with degreaser. Now it's gorgeous!
Honda powersports has my piston clips and kick shaft snap ring. Will finish cleaning the cases and then focus on inspecting the transmission.

 

[BildoNC]

I dig your pics background

 

[doode]

Thanks! It's a rug my wife got at ikea. The first year we had it I kept all dirty projects outside, but, as you can see, the engine project has moved indoors since we've had it a while.

 

[doode]

My wife is very patient with me, sometimes.

I don't have a dedicated covered space for these projects, but that doesn't stop me.

 

[doode]

I've managed to get an hour or two for the past 3 nights to disassemble, inspect and clean the transmission. One of the shafts was not placed correctly on it's alignment pin and was sitting crooked leading to uneven wear. Fortunately I had parts from the upper case that I'm using, but like a squirrel, scattered them across my property and lost track of their whereabouts. Finally found them, along with the kick shaft and bits, which, after cleaning and inspecting side by side, turned out to be in better shape than the current set.
So, with everything assembled, cam chain reoriented, seals in place, I'm ready to glue the halves back together tomorrow night. One bit of disappointment is the kick shaft snap ring I purchased from the local honda powersports shop. The metal doesnt seem to be too resilient and was all sloppy and loose when I installed it. I took it off and it was a couple millimeters wider at the opening than the clip I removed. I squeezed the ends back together fairly easily, and decided not to use it. I had 2 used spares and decided to go with the one which had less wear, both seemed to be more springy and held their shape better than the new one. Let's hope I don't regret this later on.
Last note, I thought to myself tonight, why bother posting this up and documenting it. It's certainly lacks detail and isn't informative for those who are looking to rebuild, but I figured it shows that it can be done by someone who has a full time job, 2 kids and no covered garage space to work in. I have a plastic tub, a dining room table and a milk crate with some wood to keep the engine from falling in.

 

[doode]

Got some time to finish reassembling and now can flip over and start the top.
Other than the incorrectly installed transmission, one bearing guide was missing and another was broken.
The oil slinger lock washer was missing and the shift spring with the straight nub was missing the nub. Totally could've been worse, but I really want to contact the PO and ask for the info of the dude who built this thing.

 

[doode]

Some of the gasket surfaces look like they've been attacked by an impatient person with a butter knife.

Head gasket had a leak when I got it, but was masked by black rtv. Didn't see it initially, but I noticed it on closer inspection.

 

[doode]

E2 stamped on the head.

Primary difference between the E2 and this M7 are the height of the cooling fins. See finger.

 

[doode]

E2 head is from mid/late 68, apparently. It has early construction but 8mm studs.

So... I've got some funky cylinders I considered using. 73mm bore with large dia sleeves. Piston measures 73.5 at the skirt and 73.0 at the top. I decided against it for this build, but will start another soon and try and work out those details.

With the rings on and pistons installed, I noticed the crank didn't turn at all, and there was a lot of resistance with a wrench. Utoh. I didn't work on it this past week, but thought it was spinning smoothly after joining the cases, but don't remember testing it after I installed the clutch and oil slinger. Maybe the primary gears were binding with the clutch? So, off things came, until I remembered seeing uneven wear on the stator... Like the generator was rubbing on it. Removed the stator cover and now all spins smoothly. I'll check it now to see what's up with that.

 

[misterguitar]

Hopefully no Guinnea pigs were harmed rebuilding this engine.

 

[Colorado Pablo]

Hey Doode,

Keep up the good work!

I'm doing essentially the same thing...working from 2 CB350 (a '70 and '72 I think)engines in an attempt to get one decent engine. It's totally amazing what you can find in there! You would have thought at stripped screw number 10 or 15 the guy would have figured that he needed a different screw driver but not this guy. He even stripped out the windage plate screws. Not one bolt or screw un-molested.

What did you use to get the pistons installed? I've seen some fancy Honda tools (on the vid series Saturdays Wrench on YouTube) but was hoping for something less elaborate. I've worked on smaller chain saw engines and I just use my fingers but I'm not sure that will work with these rings.

Good Luck!

Paul

 

[Lefty]

Hey Doode,

Keep up the good work!

I'm doing essentially the same thing...working from 2 CB350 (a '70 and '72 I think)engines in an attempt to get one decent engine. It's totally amazing what you can find in there! You would have thought at stripped screw number 10 or 15 the guy would have figured that he needed a different screw driver but not this guy. He even stripped out the windage plate screws. Not one bolt or screw un-molested.

What did you use to get the pistons installed? I've seen some fancy Honda tools (on the vid series Saturdays Wrench on YouTube) but was hoping for something less elaborate. I've worked on smaller chain saw engines and I just use my fingers but I'm not sure that will work with these rings.

Good Luck!

Paul

How about some of those big tie straps you can remove with a little flat screwdriver.

Enjoying the build doode!

 

[doode]

Hopefully no Guinnea pigs were harmed rebuilding this engine.

The family rabbit did occasionally have to give up her indoor cage for me to put stuff on... it was one of the few spots that didn't have little bunny hairs on it! She would hop around and lay by me as I worked.

 

[doode]

Haha, too funny about the stripped fasteners!

For the cylinders, I eases then on gently. Not the best idea... and hands down my least favorite task. I should invest in some ring compressors. It's not worth it to break a ring...

Hey Doode,

Keep up the good work!

I'm doing essentially the same thing...working from 2 CB350 (a '70 and '72 I think)engines in an attempt to get one decent engine. It's totally amazing what you can find in there! You would have thought at stripped screw number 10 or 15 the guy would have figured that he needed a different screw driver but not this guy. He even stripped out the windage plate screws. Not one bolt or screw un-molested.

What did you use to get the pistons installed? I've seen some fancy Honda tools (on the vid series Saturdays Wrench on YouTube) but was hoping for something less elaborate. I've worked on smaller chain saw engines and I just use my fingers but I'm not sure that will work with these rings.

Good Luck!

Paul

 

[doode]

Thanks! You know, this last part is the easiest... But I've been getting my balls busted at work and I haven't been in the mood to finish.

How about some of those big tie straps you can remove with a little flat screwdriver.

Enjoying the build doode!

 

[Yendor]

Typically these 350 motors don't require Ring compressors to get the Pistons into the cylinders.

The TAPER at the bottom of the Cylinder Sleeve is more then sufficient to gently push the piston into place with the rings compressing naturally as the taper narrows.

BUT... with the cylinders you show that were bored out to 73 mm that may not work since it looks like the taper has been bored away leaving a straight edge.
For those you will likely have to use a ring compressor or some other method to get the rings to seat into the piston grooves before inserting them into the cylinders.

Good luck let us know how it goes.

 

[doode]

Spent some time tonight being confused and thinking I misplaced parts.
In the end, my cam and rockers were next to the engine, but I had already gone through the trouble of grabbing all the skinny cam parts. Since I have the two together, might as well document the differences.

Rocker pins- threaded end is slightly different construction, but diameter is the same.
Rockers- fat version has square pads and a notch. Skinny version has more robust construction and higher lift.
Cam shaft- skinny cam has taller lobes
Sprocket- fat sprocket won't fit on skinny cam, lobes too tall. Skinny sprocket fits on fat cam but there is play when not bolted. I guess the diameter is larger on the skinny cam.
Rocker box- skinny cam won't fit in the fat cam box- lobes too tall.

Since I've gone through the trouble of pulling the skinny setup, I'll install it and set the fat setup aside for something else. Maybe for the 73mm pistons...