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Discussion Starter · #1 ·
Here's how I found her.



She was was dusty, wouldn't run, had obviously been down a dozen times, all the electricals were dead aside from the starter and the horn, and last, and probably least, there were fist or better-sized holes in the original silencers silencers. On the other hand, she had a title, good tank, good side covers, good paint, and seems to to turn over nicely. I put her in the truck for a mere $300. :D

When I got home, I sat for a while and though about what I wanted to do with the bike. After a painfully reasonable talking-to by that little financially-minded devil that sits on my left shoulder, I decided that a college kid can't afford a full resto. For the time being, I've just the decided to make the best of what I have and only buy parts sparingly. Thankfully, it seems you can take the elbow grease over cash route quite often with these old bikes and end up with pretty good results.

I'm picking up a camera this weekend, so I'll give everyone some pictures of where I am as the journey goes along, but for now I have a couple questions:

1. As I said, my electrical system was DOA, aside from the starter and horn. The PO had an aftermarket ignition switch (or at least relocated the stock one, but think it's aftermarket) installed on the bars, so I thought that would be a good place to start. I pulled down the rubber boot that covers all the wiring below the switch and the problem was immediately apparent. There were four wires: red, black, brown, and brown + white stripe. The br and br+w were melted together and not making contact with he switch. Where should these be connected on the switch? The black and red are both connected to their own solder joints and the there is a brown jumper wire connecting two other joint on the switch, but there's no unused or broken solder joints or anything where the br and br+w went, so I'm scratching my head a bit .There is a large metal clipish thing on the bottom, would they connect to that? (As you can tell, I'm clueless with electrical systems.)

2. Will open exhaust dramatically hurt power on these bikes? While I'm looking for new silencers, I was just planning to up the main jets too 100, 102, or 105, as I've heard all work, and running the headers completely open.

3. What aftermarket exhausts will fit? Am I going to have to go universal with an adapter or is there stuff out there that will mount right up?

Thanks a bunch everyone! I hope to keep this thread pretty active with lots of pics and motivation!
 

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Discussion Starter · #3 ·
So I experienced catastrophic engine failure while trying to work out some kinks over the weekend. When I pulled plugs one was crushed on the end(the electrode was MIA). The crankcase was also full of gas. I assume the latter caused the former somehow, does that sound about right? In light of this horrifying sight I decided to test compression. Cylinder 1 tested well, but I got a big whopping 0psi on #2. Today I pulled the engine apart. I never saw the electrode(it must have made its way out the exhaust valve), the piston was dinged pretty bad and there were marks all over the piston face as well as on the domed area that contains the valves(what's that called?). Cylinder one looks practically new for a bike with 7k miles. I have a couple questions before I start putting in orders on ebay.

1. The #2 side of the head is FUBAR. I know I can repair valves, but can I repair that domed area where they are contained? What about the spark plug threads? The piston nailing the plug appears to have caused some trauma to them and they will need repaired if possible. Mainly, would I be better off just getting a more serviceable head off from ebay or someone on here? PM me if you have a vert head for sale!

2. Since piston 1 is in such fantastic shape, would I be crazy to just re-ring in and call it a day or is it imperative that I replace both at the same time? If I go overbore with the pistons(1mm, probably) will I need different rings or will that stock ones work?
 

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Sensei
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The head COULD be fixed, but replacement is probably the cheaper option....
Get a whole top end or a spare engine and you can possibly use the cylinders and pistons as well
My worry would be the damage that the fuel thinned oil could have caused (rockers, cams and journals)
Was it a "long reach plug"? Some 175's ran short plugs, some long....
 

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Discussion Starter · #5 ·
In all likelihood, I'll just go for 1mm over on both cylinders. A new head and new pistons with freshly bored liners should eliminate any real concerns, no? I understand the bottom end is pretty tough on the 160/175.
 

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Sensei
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I may have a good spare head, I'll check....
Why go 4th over? have a machinest check and go whatever he recommends....
 

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Discussion Starter · #7 ·
I don't know much about this process, so that sounds like a plan. I figured it would just give me like a .1 more HP or so. :D

If you have a spare head I would be ecstatic. Please let me know.
 

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Discussion Starter · #8 ·
One question: How do I remove the rocker arms? I have the points plate and spark advancer removed. The manual says to rest the rocker on the cam lobe heel. Is that just when it drops back down from the height of the cam lobe and all the valves are closed? If so, what's next? To remove the rocker shafts, do I just loosen the screws beneath the spark advancer? Sorry for all the questions, but much of this is still very foreign to me. I'm keeping my head down and making progress though.
 

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catzor said:
One question: How do I remove the rocker arms? I have the points plate and spark advancer removed. The manual says to rest the rocker on the cam lobe heel. Is that just when it drops back down from the height of the cam lobe and all the valves are closed? If so, what's next? To remove the rocker shafts, do I just loosen the screws beneath the spark advancer? Sorry for all the questions, but much of this is still very foreign to me. I'm keeping my head down and making progress though.
As I recall, you can screw a bolt into the open end of the rocker arm shaft, pull it out.
You can't pull them out till you have the cam out and covers off.......
 

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Sensei
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The "heel" is anywhere in the "base circle' of the lobe ( loosest/most clearance)..... You DO have to remove the phillips head screws and then remove the cam bearing journal blocks (housing for advance unit and tach drive respectively).... Then a bolt threaded in the end will act as a "handle" with which to pull the rocker shafts....
 

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Sensei
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I Found a complete spare engine....
It runs, and still is together, but I CAN pull the (presumably) decent head.....
I don't want to tear it down without a commitment as they tend to lock-up left open....
E-mail me as [email protected] or phone 540-525-5199 if you are in a hurry...... (CMSNL has one left, but 235 Euro is about $325 US, plus shipping....)Steve
 

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Discussion Starter · #12 ·
Progress feels very good, especially when you're flying as blind as I am :D Here's a couple pic...

The ol' chicken-hawk at the beginning of the day:


Then after the tear down:



Everything came apart easily, except the shaft that pins the center stand to the frame and serves are the mounting point for the rear brake pedal. It's bent pretty badly. I guess some 300lb bubba stood on the rear break and did it at some point... :?: There's very minimal rust, even on the battery box, so I think I everything will clean up very well with minimal effort.

Okay, now it's Q&A time.
1. How should I prep the frame for paint? Wire wheel+an a LOT of sanding?
2. I read once, I believe it was on this forum even, that you can buy a set of 31mm clip ons from some asian company(Taiwanese, I think). Apparently, they use them for some popular type of tiny-bike racing they have over there. They were literally sub-$10(Ain't the American dollar a beautiful thing?) and a couple folks said they were actually half decent. I'd love to try that out before dropping 100+ on Woodcrafts. Anyone know the link? I've searched like hell.
3. My old head gasket was fully bridged so to speak. That is, the gasket material actually formed three complete circles by having gasket material that bridged the gap on either side of the cam sprocket. My new one, on the other hand is "unbridged" and just strictly follows the mating surface. If anyone understands wtf I'm talking about, can you tell me if this will be a problem?
 

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Before you buy parts on Evilbay, check your local Honda dealer. You can search every part online and see if it is still available. And it's usually cheaper than Evilbay, plus no shipping charges if you're picking the parts up.
 

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As far as frame painting preparation, don't even consider wasting your time with a wire brush! Media blasting is the correct solution if you want to do it right the first time.

I'm not saying it isn't possible to wire brush a frame down, but if you do, trying to "save money"- I bet you'll never do it again!

Good luck with your winter project, I will be looking for progress/updates.
 

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Discussion Starter · #15 ·
Hey everyone! I hope the winter builds are going well.

Progress has been slow and steady. I'm going to for the elbow grease approach, as opposed to the ebay+credit card one, so no task is a simple one. My ready-to-install parts pile keeps growing! :mrgreen: As soon as I'm done painting the frame, I'll start reassembling and I'll have some pics/videos for everyone!

As of now, I'm trying to separate the forks and replace the seals. The manual is a bit confusing on this task so if someone can clarify with a step-by-step, I would be very pleased.

It seems like it's:
1. Remove from bike
2. Remove cap/spring, drain oil
3. Undo bottom bolt that retains the dampener (I can't get mine to budge, any tips?)
4. Yank like hell
Am I missing something? The manual mentions a circlip on top of the seal, but I don't see one on my k7. Do I need to remove the chrome cap over the lowers to separate them apart?
 

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Sensei
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The K7 has essentially the same forks as a CB200.... THERE IS a snapring (under that chrome cover which I THINK grabs like a bayonet light bulb ...Lugs in an "L" shaped slot...Slight turn and pull)... AN impact with the proper long allen bit works best for the damping rod bolt removal, and the tube won't come out until you remove it....You CAN/SHOULD reinstall the spring and cap bolt, it will help keep the damping rod from spinning with the allen...
 

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Discussion Starter · #17 ·
Thanks sprint! I got the forks apart but the seals are STUCK. The forks (and the rest of the bike) are free of corrosion so I think I may be overlooking something. Is there something specific I need to do to get the seals out?
 

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catzor--

I was able to find and download a manual for my CM on this site; have you looked for one? I bet it'll make this work a bunch easier for you, especially if you're in a rush and don't want to waste time waiting for a response.

I have fond memories of the CB175...it was the first bike I rode on the street AND I got cuffed by the police one day...I was joy riding it in town, no tags, no inspection. Only reason I wasn't "arrested" was because it was the day before my 17th b-day. Cop took me directly to the judge. Didn't know at the time that he and my dad were friends (the judge). That judge read me the riot act, threatening to throw the book at me, put the fear of God into me, and then released me to my dad. Dad didn't say a word...apparently he was outside the judge's chambers listening in.

Ah...growing up...
 

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Sensei
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Right beneath the chrome cover is a dust wiper,... then the circlip,... then the seal... If the wiper and circlip are out, pry out the seal (carefully) and put the new parts back in.... a little heat might help...
 

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Discussion Starter · #20 ·
I have downloaded the manual. It doesn't apply to my K7 model specifically, but I imagine the vast majority of things are similar. I don't mean to be overzealous with my question asking, I'm just a bit of a mechanical loner. No one in my family is into wrenching, nor are my friends. I'm loving every second of learning and loving the progress even more, but I do have a tendency to get stuck without many options besides the almighty hondatwins forums. :lol:

In related news, I freed up and replaced my fork seals. Long story short, I boiled them and pried the outer edge rather than the inner ones and they came out. It took A LOT of force, but they came out cleanly. Another day, another part ready to ride on. I'm like a giddy little kid here. :D
 
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