Random questions

kirrbby

Well-Known Member
Gaaaarry...
NE51OQGGx4y08a_1_1.jpg

I'll see you in your dreams Gary...
 

kirrbby

Well-Known Member
My engine seems to have an exhaust restriction.
Lol.

My question here is...WTF.
How does this happen. I assume it might just be caused by water getting inside of the exhaust...like a bike left outdoors for many years. It doesn't look good for this, good lookin head.
IMG_20181207_123659618.jpg IMG_20181207_123619469.jpg IMG_20181207_123632003.jpg IMG_20181207_123649872.jpg IMG_20181207_124810750.jpg IMG_20181207_124822724.jpg IMG_20181207_124949080.jpg
 

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kirrbby

Well-Known Member
10 minutes to break thru.
IMG_20181207_130655251.jpg

10 more minutes to be ready for the... Well, blast cabinet I spose.
IMG_20181207_131735581.jpg IMG_20181207_131752541.jpg

...I'm thinking I probably should have worn a dust mask for this.
 

kirrbby

Well-Known Member
Well I paid 60 bucks for this. These pics were the only indication that there might be a problem with it.
s-l400 (15).jpg s-l400 (16).jpg

This is what was under those valves.

IMG_20181207_140343976.jpg IMG_20181207_140355024.jpg IMG_20181207_140425128.jpg IMG_20181207_140412179.jpg IMG_20181207_140402033.jpg
 

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69ST

Well-Known Member
Gonna be close, at best, but IDK that this casting is paperweight/scrap metal...as fugly as it looks. Have to assume that these valve guides are all done, which complicates further evaluation. Only way to know if the valve seats can be recut is to cut them and see if there's still enough solid, uniform, metal remaining to properly restore the valve seats. That will require valve guides that are good-to-go. I'm guessing that the guides can be replaced, based on what I can see, so far. The intake port looks decent, the exhaust port should clean-up acceptably. Nice thing about the exhaust port is that the roughest surfaces look to be concentrated on the short-turn-radius (a.k.a. port floor) side, just where material can be removed to improve exhaust flow without substantially increasing port volume. IMO, it's a question of whether you're willing to throw a set of guides at this casting. You'll need to spend some time with a die grinder, cleaning the EX port, and source a pair of new valves. But, your labor is free, unless you charge yourself for it ;) and, if it really is toast, you'll have other uses for new valves, sooner or later, if you don't already.
 

kirrbby

Well-Known Member
I DO love your optimism Bob.
I'll post up a few more... gooder, closer, pics. Then, if you still think there is hope, I'll put in the time and money's to save it. It would be traumatic for me to have to drop this one into the scrapper, but, to my eye, it looks too far gone.
 

69ST

Well-Known Member
I wouldn't be surprised if it's possible to have 12v style hardened seat inserts installed. There are just the minor issues :whistle: of finding a shop capable of doing the job properly...and...of course... what they'd charge. Given enough time, talent & bucks, it's possible to fix just about anything but a broken heart.
 

69ST

Well-Known Member
IDK, Kirby, this photo group, the first two shots especially, make the casting look like... a victim of the US women's gymnastics program(!):eek:

Seriously, it looks like there's no metal left for a complete, 360-degree, valve seat. The money question, whether it's digital photography artifacts, or a truer representation of actual condition, than the pix shown in #105. I'm not optimistic enough to think that I can cut metal that no longer exists.
 

kirrbby

Well-Known Member
Yes, full of holes. Like cheese, or...toast. lol

Maybe I'll take it to Gary at VHMT. That way I won't have to scrap it.
He'll find someone who only wants one to look at, or who will spend a fortune to have it repaired, or something.

I'll just take it to him and ask him how much it's worth...lolol If you know Gary, that's funny shit.
 

kirrbby

Well-Known Member
Random question.
Why did Honda move the condenser OFF of the stator plate on SOME bikes??
There has to be a reason.
 

allenp42

Well-Known Member
Why did Honda move the condenser OFF of the stator plate on SOME bikes??

SL70 is another one that has the condenser mounted to the ignition coil and it's got the 1/2 wave setup. Don't know enough about the SL70 to even offer up a guess. The XL70 has the condenser on the stator plate.
 

OLD CT

Well-Known Member
:(
Yes, full of holes. Like cheese, or...toast. lol

Maybe I'll take it to Gary at VHMT. That way I won't have to scrap it.
He'll find someone who only wants one to look at, or who will spend a fortune to have it repaired, or something.

I'll just take it to him and ask him how much it's worth...lolol If you know Gary, that's funny shit.
Guess the thinking was, it's a rare part. Now not so much. I sold a nice head that was good to go for $75 a few months back. Not a fancy diamond head though. :(
 
Yes, full of holes. Like cheese, or...toast. lol

Maybe I'll take it to Gary at VHMT. That way I won't have to scrap it.
He'll find someone who only wants one to look at, or who will spend a fortune to have it repaired, or something.

I'll just take it to him and ask him how much it's worth...lolol If you know Gary, that's funny shit.
Is that a special Head?
 

kirrbby

Well-Known Member
The casting has a diamond, and lines. 2 lines on this head, some have 3. But that is typical of a very low vin# CT70...silvertag engine. So...kinda special, but still not worth going crazy trying to save it. You might squeak 150-$180 out of a real nice specimen, from a determined buyer.
 

kirrbby

Well-Known Member
Sorry for this very random bit of info. I plucked it from another thread, and I'm posting it here so I'll be able to find it easier next time.

Here's how I think the kicker works...
When you move the kick lever, the pinion gear slides to the end of the kick shaft, where it meshes with first gear on the countershaft, which is always meshed with first on the mainshaft.
First gear is PART OF the main shaft, so this spins the mainshaft which has the big primary gear splined onto the other end. The big primary is meshed with the small primary, which is splined to the clutch center, which uses the clutch discs (friction) to spin the clutch drive plate, which is splined to the crankshaft...rod...piston...
Simple, right?

So yes, if the kickshaft does what it should, the big primary gear will spin when you kick the lever...
The outer clutch housing will only spin if the clutch pack is strong enough to overcome the pistons compression and spin the crankshaft.
 
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