KC Powersports KC70cc HELP

[TopCatGr58]

Hey Tony,

Thanks for the info, wasn't sure how HOT to take it, the thread I had read said 200. Will 350 damage the OTHER valve seal? I don't know what temps it gets up to during normal operation, plus there's a fresh flow of oil helping to keep it cooler up there?

The rocker arm shaft wasn't bent after all, there was just a slight deformation of the slot/hole that it fits into, but I was able to get it out without much effort, so hopefully it'll be okay. I may need to take a drill bit to gently ream out that hole a few thou to allow the pin to spin freely so the the oil will be able to flow around it to keep it and the rocker arm lubed!?

I ordered the parts today, about $45.00 worth, and the kid WILL be paying me for them, he has a job! And perhaps after hitting his pocket/wallet with this he'll learn how and when to shift gears, he said he knew how, but apparently he didn't do it!

The valve guide has two levels for the springs, the inner spring sits higher than the outer spring, so which one did you shim, and how, did you just take some washers and stick them under the springs?

The Forum only allows 5 minutes to edit your posts, so it's kinda tough for regular members to do so. I was able to remove the previous error laden post!

Thanks for the info, I'll post when I get it done and back running again!
T.C.

[Geezer]

You're better off not repairing the damage to the hole where the rocker pin goes. The last thing you want is the rocker pin rattling around in its bore. Since the little twit is working, I would have thought long and hard about making him pay for a new cylinder head casting.

I've replaced a lot of valve guides over the years and I always heat to 350 degrees. Yep, it'll probably cook the other guild seal but I always replace them all when I have it down that far.

If the outer spring binds, don't worry about the inner spring. The idea behind dual springs is that when one spring hits its flutter frequency, the other isn't and will pull the valve back and reduce float. I shim between the head and the lower spring seat and between the lower spring seat and the large spring. The problem is finding just the right washers for the job. If you have access to a lath, you can bore a washer of the right OD to have the right ID.

I probably spent more than 5 minutes editing out the spelling and grammar problems before I decided I needed to add more technical info. I’m dyslexic as hell and if I didn’t cut and paste my posts from MS word, I’d look even more stupid here than I do. You can tell the posts here I don’t spell check, they’re often a mess.

[TopCatGr58]

Dayam....I'm pissed!!!

Well, I finally got the parts in from the local dealer! I heated the head to 300 degrees for a good 45 minutes, and was able to tap out the old guide fairly easily!

I then proceeded to take the new one out of the freezer where it had been for the last 24 hours, afixed the rubber O-ring seal, and proceeded to put it into the head. I met some resistance, so I had a socket that I "thought" fit it fairly well, and was using it to tap....then hammer the guide in. It was going but with a fair amount of hammering force. Finally felt it seat, and pulled out the socket to see a 'piece' of the valve guide rattling around inside the head!

Apparently the socket had slipped some and struck the portion that the valve seal fits onto at an angle and BROKE the thing off! I didn't know these things were CAST IRON?!?!? Brittle crap!!!!!

So...my repairs have come to a standstill again, as I have to order ANOTHER valve guide. I got the busted NEW one out, and I found a much better fitting socket for tapping in the NEXT new one once it comes in!! Live and learn I guess!
T.C......grumble, grumble!

[Geezer]

If you have access to a lathe, turn a brass rod down for a more precise guide punch. The effort will be worth it.

Geezer

[TopCatGr58]

Hey Geezer,

I have a lathe, but no brass!! I was just thinking, I've got a large "C" clamp, would that be a safer technique, sorta like a slow PRESS, with the good fitting socket, to PRESS in the Guide instead of trying to hammer it in, after I baked it at 300 degrees of course!!

I stopped by the dealer and ordered another guide, about $9.00, not too bad, the valve was the most expensive part, thankfully I haven't messed it up......yet!
T.C.

[Geezer]

Do you have any mild steel bar? So long as it's softer than iron, it should do. Turn it so that there is a rod the same diameter at the valve stem and leave a shoulder that matches the shape of the end of the guide.

A C-clamp would be to slow and would wick off heat to fast from the head. You want to tap it in quickly.

Tony

[TopCatGr58]

Getting Reamed, and liking it!

Hey Geezer and Gnepig and others,

Well, the second guide I broke the shoulder/lip off of! So... I ordered a 3rd, and then when I got it, I went to the local Motorcycle Machine shop....McBride(Spiderman), and they told me also about baking the head at 350, BUT to keep the guide at room temp, put some antiseize around it, and then get/make a special tool to drive it in, what I didn't realize was that I was to be hitting on the actual nipple that the oil seal mounts to, not the shoulder/lip!

I then also found out that the guide and valve didn't fit each other, and that they came that way from the parts supply!! After the guide is installed, the guide THEN needs to be REAMED out to match the diameter of the NEW valve!?

Well, I didn't have any BRASS, but I did have some raw aluminum plate, cut a small slice and then lathed the end to match the guide, and was able to heat and tap/hammer the guide in WITHOUT breaking it!!! Went back to the machine shop, and had told them that I was working on this for a neighborhood kid, and so he did the reaming FOR FREE!!!! Only took him a couple of minutes!

Got the head back home, lapped the new valve/seat, and then had to make a special tool to use with my C-clamp to compress the spring to put the keepers back in.






Below is the small dent in the top of the piston, I just used a dremmel sanding disc and smoothed it out to prevent any hot spots and detonation from chips, etc.!


Here is the bike ALL BACK TOGETHER!!


And here I am test riding it, ....I know, NO HELMET!!

SO, again thanks for ALL OF YOUR HELP AND GUIDANCE!!!
Mission Accomplished!!
T.C.

[Geezer]

It's cool that it all came together but not only would I have refused to be seen in plublic on it, I shure as hell wouldn't have posted pix. ;o)

Geezer

[sixtysix]

I like the picture, with Godzilla in the background no less.

[prometheus578]

I have to agree with Geezer!

[GNEPIG]

I have to agree with Geezer!

.. guys that have this kind of opinion about little bikes are the guys that have little peckers and are afraid someone will think they are not a biker, if they are seen near a little bike ..
..those little bikes are a blast to ride!

[Geezer]

Originally posted by GNEPIG
... guys that have this kind of opinion about little bikes are the guys that have little peckers and are afraid someone will think they are not a biker, if they are seen near a little bike ..
..those little bikes are a blast to ride!

I think a big guy on a little bike is just silly and has nothing to do with the size of your Johnson.

I also think all scooters should be crushed and recycled back into beer cans. I may be a radical but I can live with that. ;o)

Geezer

[TopCatGr58]

No need to squabble!

Heck,

I'm so friggin' tall, even Godzilla looks like a minibike when I sit on IT, so I already think I look silly on just about anything! That was actually an action shot, you'll note both feet are on the pegs, I was rolling slowly by, just happened to get Godzilla in the shot!

And as far as "pecker" size, only SWMBO knows for sure! All I can say is that I "Wish" I was "MORE PROPORTIONAL"

Later, I made sure he at least had a helmet and was wearing it properly. Also highly suggested to his MOTHER to get him a decent riding jacket and pants, but at least my conscience is now clear! And he did pay me for ALL of the parts, even the ones I broke! At a professional rate of $69.00 /hour, he got a very good deal!

T.C.

[Geezer]

We were just poking a little fun; don't take it to serious. I'm 6'5" and I have similar problems. Actually biking has made me shorter. I was well over 6" 7' when back injuries from being pasted by a Buick when riding my Guzzi.

When I was working in shops I had a standing rule that I don't ride anything smaller than a 125 or any scooter. I really liked the Kawie and Harley shop I worked at, Kawie didn't have a scooter in 89 and we didn't work on dirt bikes out of warranty.

Geezer

[prometheus578]

"I'm not a "Gifted Mechanic" in the tool department..."

, Kawie didn't have a scooter in 89

Kawi shop I work at just ordered 25 Vespa's! (Damn the new owners!)
Might as well take my "tool" to the bench grinder and shorten it a bit more!
"Oh the pain... the pain..." (Dr. Zachary Smith)