Welcome Guest [Log In] [Register]
Welcome to CCM MaD. We hope you enjoy your visit.

If it's your first time here please make your first post in either the 'Welcome' or 'Chat' section so we can verify your account quicker, untill verified your posts will need to be manually approved before they show, please be patient.


Join our community!


If you're already a member please log in to access all of our features:

Username:   Password:
Add Reply
604 valve clearance adjustments; adjusting clearance
Topic Started: May 22 2012, 06:38 PM (1,585 Views)
richyrich
Commoner
[ * ]
just enquiring if anyone can give some basics for checking valve clearances on 604 sm. i know its basic stuff- if you've done it before.
i have the engine manual which gives gap sizes. also i have a haynes manual for a virago!! :what:
so i can maybe figure it out- just wondered what i have to get showing through the round window (sounds like playschool) , etc, etc. so that the valves are in correct position.
a few tips appreciated, thanks :chin:
Offline Profile Quote Post Goto Top
 
richyrich
Commoner
[ * ]
in answer to my own post, found some good info on dansmc.com/valveclearence.htm
Offline Profile Quote Post Goto Top
 
Monty
Member Avatar
Charlie Big Banana's
[ *  *  *  *  *  *  *  *  *  * ]
I personally set them to 4 and 6 thou, though manual says 2 in and 2 out

Always worked fine for me.
If it aint sharp I can play with it
My Utube Channel, lots of bike vids here. Subscribe if you likehttp://www.youtube.com/user/choppermark?feature=watch

Posted Image
Offline Profile Quote Post Goto Top
 
richyrich
Commoner
[ * ]
rotax manual i have says 0.05mm for both intakes and exhaust :chin:
i managed to get them set, dansmc.com is good for telling how to get top dead centre, etc.
thanks
Offline Profile Quote Post Goto Top
 
bighit
outta here
[ *  *  *  *  *  *  *  *  *  * ]
id go with monty . 2 thou is way too tight . a page from a news paper is roughly 3 thou.

lowest we go with any engine at work is 6 thou even if they state 4 thou in the auto data books


too tight and you will get a burnt valve and seat as they will not close properly when the engine is hot
Offline Profile Quote Post Goto Top
 
Monty
Member Avatar
Charlie Big Banana's
[ *  *  *  *  *  *  *  *  *  * ]
0.05mm is 2 thou :D

4 and 6 thou has worked well on many engines, 2 thou is a bit tight,

I would rather hear a slight tapping than none at all,

too tight is worse than too loose
If it aint sharp I can play with it
My Utube Channel, lots of bike vids here. Subscribe if you likehttp://www.youtube.com/user/choppermark?feature=watch

Posted Image
Offline Profile Quote Post Goto Top
 
bighit
outta here
[ *  *  *  *  *  *  *  *  *  * ]
Monty
May 23 2012, 08:13 PM
0.05mm is 2 thou :D

4 and 6 thou has worked well on many engines, 2 thou is a bit tight,

I would rather hear a slight tapping than none at all,

too tight is worse than too loose

iwas told its when it stops tapping you should worry lol
Offline Profile Quote Post Goto Top
 
richyrich
Commoner
[ * ]
it did seem a bit tight, not that i have done them before!! :sweat:
Offline Profile Quote Post Goto Top
 
richyrich
Commoner
[ * ]
just read on motorcycleproject.com some info that says its a popular misconception that valve clearance is to compensate for heat expansion. it says this was due to early days of pushrod engines where the valves expanded more than the casings.
it says that on ohc engines that with heat the clearance increases.
no criticism on this matter please- i have just read it, and i'm no mechanic!!! just stating what i read.
:drinks:
Offline Profile Quote Post Goto Top
 
richyrich
Commoner
[ * ]
richyrich
May 23 2012, 10:11 PM
just read on motorcycleproject.com some info that says its a popular misconception that valve clearance is to compensate for heat expansion. it says this was due to early days of pushrod engines where the valves expanded more than the casings.
it says that on ohc engines that with heat the clearance increases.
no criticism on this matter please- i have just read it, and i'm no mechanic!!! just stating what i read.
:drinks:

got that slightly wrong- on the pushrod engines it's to do with other parts expanding more than the valves, thus the valve clearance reduces- best to read the article...

<_<
Offline Profile Quote Post Goto Top
 
bighit
outta here
[ *  *  *  *  *  *  *  *  *  * ]
richyrich
May 23 2012, 11:18 PM
richyrich
May 23 2012, 10:11 PM
just read on motorcycleproject.com some info that says its a popular misconception that valve clearance is to compensate for heat expansion. it says this was due to early days of pushrod engines where the valves expanded more than the casings.
it says that on ohc engines that with heat the clearance increases.
no criticism on this matter please- i have just read it, and i'm no mechanic!!! just stating what i read.
:drinks:

got that slightly wrong- on the pushrod engines it's to do with other parts expanding more than the valves, thus the valve clearance reduces- best to read the article...

<_<

not doubting what you read but in the autodata books we use at work (im an engine reconditioner by the way) they sometimes give you a setting in say the 2006 book but its different in the 2008 book and still the same engine code ,so the engine makers must have decided that the clearance was wrong the first time . more often than not they widen the clearance rather than tighten it .

most engines are an average 8 inlet 16 exhaust -+ 2 thou either side of them values( thats cars by the way not bikes ) . then you get the vauxhalls that are 20thou inlet and exhaust . then you get some that are set when the engine is stone cold and some that are set when the engine is warm


end of the day ,the engine makers spend tens of thousands designing the engine and a guy on the internet then says he is wrong lol who is right ? i dont know
Offline Profile Quote Post Goto Top
 
richyrich
Commoner
[ * ]
thanks for feedback, it's all new stuff to me. one thing with buying a ccm - i am learning more about engines and carbs than i did before!! :drool:
Offline Profile Quote Post Goto Top
 
richyrich
Commoner
[ * ]
whilst i'm on with the valve clearances- i noticed that the covers that are on the ends of the arms- not sure what they are called- look a bit like airgun pellets is best description-
well they look a bit loose/worn- should these be replaced?
thanks :what:
Offline Profile Quote Post Goto Top
 
bighit
outta here
[ *  *  *  *  *  *  *  *  *  * ]
richyrich
May 24 2012, 10:26 PM
whilst i'm on with the valve clearances- i noticed that the covers that are on the ends of the arms- not sure what they are called- look a bit like airgun pellets is best description-
well they look a bit loose/worn- should these be replaced?
thanks :what:

what bits ?Posted Image
Offline Profile Quote Post Goto Top
 
richyrich
Commoner
[ * ]
i just been looking at diagram before you posted it.
i think they are on caps on bottom of adjusting nuts? look like come already fitted as part of screw.
just on my bike one or two of them look bit loose!
Offline Profile Quote Post Goto Top
 
Monty
Member Avatar
Charlie Big Banana's
[ *  *  *  *  *  *  *  *  *  * ]
Thats fine mate, most engines the end of the screw touches the top of the valve, the rotax goes one better and fitted a slipper (for want of a better word) they flop about so no worries its normal
If it aint sharp I can play with it
My Utube Channel, lots of bike vids here. Subscribe if you likehttp://www.youtube.com/user/choppermark?feature=watch

Posted Image
Offline Profile Quote Post Goto Top
 
bighit
outta here
[ *  *  *  *  *  *  *  *  *  * ]
are they like this Posted Image

the white plastic bit? we call them elephants feet( its a ball end on the adjuster and the metal bit inside the plastic bit that touches the valve stem has a socket like an elephants foot does ).
thats a Mitsubishi L200 rocker arm

you can only buy the bottom bit for the L200 with the screw adjuster built in , so as monty says your ones will be fine as they are meant to move . causes less wear on the end of the valve stem
Offline Profile Quote Post Goto Top
 
richyrich
Commoner
[ * ]
yes, thanks to you lot for advice. good job i checked on here!
went to see local mechanic today and he said same regarding clearances.
i have re done them, used my metric gauge and put digital verniers to convert into imperial.
nearest i could get on my metric was a 5 and a 7.
i probably was a bit overcautious and done them a bit loose- they are a bit noisy so will prob have to redo.
on plus side- bike starts with no throttle and is accelerating smoother than it has before ( helps with 45 pilot i put in as well).
off for mot tomorrow so hopefully it ok
:drinks:
Offline Profile Quote Post Goto Top
 
bighit
outta here
[ *  *  *  *  *  *  *  *  *  * ]
richyrich
May 25 2012, 10:31 PM
yes, thanks to you lot for advice. good job i checked on here!
went to see local mechanic today and he said same regarding clearances.
i have re done them, used my metric gauge and put digital verniers to convert into imperial.
nearest i could get on my metric was a 5 and a 7.
i probably was a bit overcautious and done them a bit loose- they are a bit noisy so will prob have to redo.
on plus side- bike starts with no throttle and is accelerating smoother than it has before ( helps with 45 pilot i put in as well).
off for mot tomorrow so hopefully it ok
:drinks:

verniers are called verynears in engineering places , not as acurate as a micrometer but they are pricey . get a set of draper feelers for a few quid and they come either metric or metric/imperial (both on the feelers ) or get the motion pro Posted Image

a few quid each but handy for doing the adjusters on the 644ds .

tip. bend the first half inch of your feeeler blades to 90 or so degrees . if you keep them straight and use one that is fairly thick you can push the valve down a little giving a false clearance . also clean oil off shims and followers if doing a shimmed head Posted Image as a little oil will give a false clearance also as the oil is thick . you get them type tappets on most car heads and some bikes also
Offline Profile Quote Post Goto Top
 
« Previous Topic · Chat · Next Topic »
Add Reply