CB200 Camshaft Modification to prevent wear/seizing

Ah ok, so thats why you drilled the other hole in the upper case..
Yeah its strange and got me puzzled when i worked on it. There's an oilcanal going all the way up to the left rod, but then they just stopped and did not drill the last little 1mm hole. Stupid if you ask me. Might be they just forgot it and nobody thought about it.

Since i'm going to machine new ears with roller bearings i guess the 175 ears mod is no use to me, but the knowledge is appreciated!
 
I've done some reading about the ballbearing cam upgrade, but can't seem to find any info other then 'its been done'. Is there anybody with info about how to do it? I could figure it out myself, but why invent the wheel again..
 
The concept is easy, it's the execution that is difficult. It takes some precision machining to get right.

The basic idea is that you remove enough metal from the cam journals and fit roller bearings in their place. Along the way, you don't want to disturb any of the oil passages.
 
I know, i already did a needle bearing conversion on the points-side. I was looking for some pictures ideally.
I want to do a ball-bearing conversion on both sides because is more reliable then needle bearing.
And it will look badass on the little scoot aswell haha

There is not enough material for ball-bearings so i would have to make new ears from scratch btw..
 
For a cam, the needle bearings will have more surface area and wear longer.

Balls are better for thrust (axial) loads. For heavy radial loads, the roller is better.

Since a cam does not have large thrust loads, needles or rollers would be the preferred bearing.
 
Sonreir said:
What's the reason for preferring ball bearings over the rollers?
Click to expand...

The workable area on the points side is so small, i had to buy a needle bearing without an inner boss. The needles are toucing the cam directly, and since there's is a oil-hole right where the needle surface is, i think it's not a superb solution. I would like to use a needle bearing with an inner boss, but then i'd have to make new ears. When i'm doing that, i'll upgrade to ball-bearings, because i think they'll outlive a small needle bearing. I'm going to do that on both sides btw.

http://www.dotheton.com/forum/index.php?topic=32298.10
page 2, about halfway down...
 
I just walked out to the shop and checked out a CB175 head that was sitting on the bench, & the ball bearing conversion looks to be very simple. The bearings are fitted over the (soft) cam core as you would expect. The outer race of the bearings does not go into the end towers though. The head is machined to take the outer race as a light press fit. The end towers would be shortened so that all they do is to feed oil into the end of the cam. That makes it similar to a CB77 which used 4 small ball bearings.

If the cam mounted points are retained I could see some issues over sealing if both sides were fed oil. It may be necessary to fit a seal to get oil into the cam end - same as a CB77 again.
 
What do you mean with 'soft' cam? Me no habla english that good.
I was not planning on machining the head to take the bearing, i was planning on making new ears out of scrap aluminium. Reason is simple, the whole head does not fit in my mill :)
Using a reamer (is that the right word) could help, but then i would not have the hole where i want it. Precisely center that is... Problem is the holes in the head are already that big... No room for error. ;)
Do you think i sould give the outer race a boss on the inside? or will the fact they're both locked from the outside (by the ears) be enough? Ofcourse i'll put the cam on the lathe to take a little off where the bearing's inner race goes - making bosses on that sort of speak. I'll make a new topic when i get to it.
Got a complete 200 engine for cheap with broken rings, so i can fuck up once hehe

I'm also working on a plate to accomodate cb400f carbs :)
 
Hello all,

A few months ago I bought a CB200 for 200 Euro's. It was not running well and had low pressure on the right cylinder. So I took of the head and cylinder to check things.
The pistons were okay but the valves where not. I 'grinded' the valves and cleaned the head.
I also sandblasted the side covers and cylinder head (now I know…stupid!) and tried to clean it afterwards…
Everything was put back together with new gaskets. I put fresh oil in the engine and everything looked ok. The engine started

But… after a few km the engine stopped. I could not use the starter to turn it around anymore. It looked like one or two of the pistons were stuck in the cylinder.

Again I opened the engine and to my surprise it was something else: the camshaft was stuck (melted) in the left aluminium ‘bearing’. It looked like it was not provided with (enough) oil.

The engine is on the workbench again. Head and right cover are of, camshaft / bearing been repaired.

Can someone give me tips how to check or improve the oil circulation? Pictures are welcome!

Thanks

Anton
 
Hey Anton! Welcome to the site. Toevallig nederlands?
You can check out my girlfriends build of her cb200 tracker. Her username is Bons.
I'm on my phone right now - cant link the page.

We did a needle bearing conversion on the cam, also hydraulic clutch, hydraulic disc brake and a external oil feed line.

Cheers!

edit, on my laptop now. here ya go: http://www.dotheton.com/forum/index.php?topic=32298.0
 
Bert Jan said:
Hey Anton! Welcome to the site. Toevallig nederlands?
You can check out my girlfriends build of her cb200 tracker. Her username is Bons.
I'm on my phone right now - cant link the page.

We did a needle bearing conversion on the cam, also hydraulic clutch, hydraulic disc brake and a external oil feed line.

Cheers!

edit, on my laptop now. here ya go: http://www.dotheton.com/forum/index.php?topic=32298.0
Click to expand...
^+1 Welcome Anton! You hit the jackpot...Bert has done the conversion and several others in this thread!
 
Hello and thanks for your replies!

Indeed I am from the Netherlands, pardon my French.

Before thinking of the bearing conversion I would like to know how the oil is supposed to flow and how to check it. Are there perhaps more simple mods than converting to needle / roller bearings?

Pictures are welcome!!

With kind regards,

Anton
 

Attachments

  • 2012-08-12 12.49.13.jpg
    2012-08-12 12.49.13.jpg
    583.1 KB · Views: 207
Wow that is one clean shiny bike. Very nice.

Any CB1160/175/200 end caps (ears) will fit a CB200 but you have to clean out any debris and check all the oilways for flow. You could also drill the left side for an oil feed like earlier motors.
 
FUCK YES.

foto-1_zps30480c2c.jpg


Anton mailed me his worn cam and housing and i did that ^^
It was one hellofajob.

Because i needed the lathe-pointteeth (dont know how you call it) to go in on the side i had to clamp it in the lathe, i had to come up with something. I had another ear lying around (same one) and i bolted the 2 together by 4 m6 bolts thru the holes already in them. I then put a rear axle with right diameters thru both and tightened the 4 m6 bolts. the axle was now stuck because the 2 points covers aligned. i clamped the axle in the lathe and took a bit of the extra one's conical shape (the part going in the head) off so i could fit that in the lathe. I then removed the axle and used the lathe to take out the material to fit the bearings.

aye?
 
Bert Jan said:
FUCK YES.

foto-1_zps30480c2c.jpg


Anton mailed me his worn cam and housing and i did that ^^
It was one hellofajob.

Because i needed the lathe-pointteeth (dont know how you call it) to go in on the side i had to clamp it in the lathe, i had to come up with something. I had another ear lying around (same one) and i bolted the 2 together by 4 m6 bolts thru the holes already in them. I then put a rear axle with right diameters thru both and tightened the 4 m6 bolts. the axle was now stuck because the 2 points covers aligned. i clamped the axle in the lathe and took a bit of the extra one's conical shape (the part going in the head) off so i could fit that in the lathe. I then removed the axle and used the lathe to take out the material to fit the bearings.

aye?
Click to expand...
is the notch I see on the ear holding the bearing in place?
 
im not so sure which not you're referring to? The bearings can not go all the way trhu, and the camshaft prevents them to go the other way.
 
Bert Jan said:
im not so sure which not you're referring to? The bearings can not go all the way trhu, and the camshaft prevents them to go the other way.
Click to expand...
that is cool Bert! I am excited to see how it works!
 
The cam mod is working perfectly.

The tacho oil leak is also gone now thanks to the new oil seal.

Just rode a few Km in Rijswijk and Delft.... it's a slow slow bike but fun to drive.

Thanks Bert Jan!
 
You must log in or register to reply here.

DTT Light or Dark

  • DTT Light
    • www.jadusmotorcycleparts.com
    www.lostapostle.ca/
    www.sparckmoto.com

    Spread the Love

    Back
    Top Bottom