[Mc69]

Well I am putting my motor back together tonight and I've run into a problem. I have a 69 cb350 motor that I put TH pistons, megacyle 123.20 cam, refaced valves...ect. Everything seemed to be going fine until I went to adjust the the valves for clearance and found out that I couldn't get any clearance between the rocker and the valve. Double checked timing and everything seems to be fine.

I found out while doing this build that between 69 and 70 there was a change in the rocker arms. My 69 rockers (286) have a lot more lift than a 70 (312). I have a set of 71 rockers that are in good shape but all my 69's are NOS. Has anybody else run into this problem before?

 

[monkey]

you may want to consider checking the valve clearances again... then you will probably have to machine the valve stems to achieve proper valve adjustment.

matt

latered

 

[joe c]

put the 71s in and send me your nos type1's! did you check your valve to piston clearance also? im not sure that they grind those 123's for the type rockers. that could very easily be your problem. im not sure that grinding the valve stem will work because it may not open the valve enough. but them im not thinking about it. plus, as the valve seats, its going to require more adjustment. so how much to grind. plus, are you running ti vlaves? wait, those valves have lash caps right? i seem to remember this happening once before.

craig?!



jc


aaron, send my wheel.

 

[monkey]

joe is right

when you send a cam to megacycle... they specify what rocker arms to use... they also reccommend that you have the rocker arms refaced when getting a cam

matt

latered

 

[Mc69]

Nope I'm running the stock valve caps (budget thing) but the megacycle package states that they grind them for the early cb's (mine) and the later.
Oh and ya gotta love that Honda charges $93 for a rocker that is 40 years old.

 

[Mc69]

I let megacyle know what year my bike and the package states it is for the early models.

 

[joe c]

are you running stock valves? stock valves dont use lash caps. i mean, i dont know, but its possible that if youre using lash caps on your stock valves, they aren't supposed to be there. i know they come with the ti valves and even the 5.5mm valves. if its too tight now, its going to tighten up even more after everything seats. i forgot that i have had valves reground on my bonneville. after one mushroomed. but i dont think you need to do that. at least ive never heard of it.

jc


aaron, send my wheel.

 

[joe c]

yeah, you can have type1 followers resurfaced for less.

93 bucks is pretty steep. but for something they only made for a year or 2, 40 years ago, to get it new, thats pretty amazing. if you really think about it. i mean, what else are you going to do?

jc


aaron, send my wheel.

 

[Mc69]

I dunno, I'm still running the stock valve retainers and there is no room. I dunno, new valve? grind off the old ones? different rockers? Help?

 

[joe c]

i wouldnt go grinding the valve just yet. what valves are you using? im guessing not stock.


jc


aaron, send my wheel.

 

[Mc69]

Thanks for the reply Joe, Yeah I'm using the stock valves

 

[joe c]

dude, i dunno. none of the motors ive seen go together or have helped put together have used both valves stock. i just know the aftermarket ones have lash caps. which im assuming come with the valve. but if they came with the cam, then i could see that youd try and fit them on and maybe they shouldnt go there. but i have no idea. other than maybe the valve stems are different lengths from the early model head to the later. sorry. i was just thinking of all of the different scenarios. if i find anything out, ill pass it on. the keepers dont matter.

jc


aaron, send my wheel.

 

[jbranson]

Many aftermarket SS valves come with lash caps because the stems tips are not hardened.
Actually...according to Pete T. SS valve tips will work harden so fast that you don't really need them. But don't pull them off on my advice...I've never built a 350.
When I order valves I specify hardened tips. I don't use lash caps and have never had a problem. But then the 350 has some pretty strange valve train geometery from what I've heard.
JohnnyB

 

[Mc69]

Well after further pursuit of an explanation I've found it was stairing me straight in the face....Wait for it...I think I have the wrong cam. Comparing old with new and comparing the forms that megacyle sent shows that this is for the later year cb's. Sending it back. Hope it doesn't take another 3 months to get another one. Thanks for all the help.

 

[joe c]

also, you may neda slotted cam gear. you didnt mention it, and forgot. the timing will be so out because of the grind that you need to have the gear slotted to get the timing correct.


jc

aaron sent my wheel!

 

[parks61]

glad i race a 2 stroke.
parks

AARON SENT JOE'S WHEEL!!!!

p.s. hope aaron doesn't give me a black eye for shouting.

 

[Mc69]

well sent the cam back to M3 last thurs and Mark is going to try to get me another...hopefully quicker than the 3 months the last one took. But Mark is a good guy so I've got faith in him. I don't know much about that slotted cam gear. This will only be the stage 2 cam from megacycle so it shouldn't be too radical to throw the timing off that much.

 

[Mc69]

well sent the cam back to M3 last thurs and Mark is going to try to get me another...hopefully quicker than the 3 months the last one took. But Mark is a good guy so I've got faith in him. I don't know much about that slotted cam gear. This will only be the stage 2 cam from megacycle so it shouldn't be too radical to throw the timing off that much.