aka rotten
Member
- Joined
- Mar 21, 2012
- Threads
- 20
- Messages
- 44
Could someone give me specks on valve adj.on briggs 17.5 H.P.ohv.engine?And do i need to have engine cool to adj.or does it matter?This is single cly. Intek engine.Thanks
Valve adj.?
- Thread starter aka rotten
- Start date
pugaltitude
Lawn Addict
- Joined
- Jan 11, 2012
- Threads
- 7
- Messages
- 1,142
aka rotten
Member
- Joined
- Mar 21, 2012
- Threads
- 20
- Messages
- 44
Thanks for the repleys gents.Could someone chime in and tell me should engine be cool or does it matter.Thanks again.
pugaltitude
Lawn Addict
- Joined
- Jan 11, 2012
- Threads
- 7
- Messages
- 1,142
Yes engine cold.
Also you have to be 1/4 past TDC on the power stroke so that the decompressor is not on or you will have wrong clearances.
aka rotten
Member
- Joined
- Mar 21, 2012
- Threads
- 20
- Messages
- 44
Thanks guy.If ya would you or someone tell me how to be sure its 1\4 in past top dead center,i think i know but im old and forgetfull.Again Thanks.
SeniorCitizen
Lawn Addict
- Joined
- Aug 28, 2010
- Threads
- 129
- Messages
- 2,140
There are mechanics that will swear by inserting a screwdriver into the spark plug hole so they can tell when the piston has traveled down a 1/4" from top dead center on the power stroke. This may work very well on some engines.
After setting valves on a Briggs single cylinder ( don't remember the horse power or numbers ) I can safely say that is not a good idea on some engines because of the geometry of the cylinder bore and the spark plug hole angle relation to each other. I used a wooden dowel rod and hearing it crack as the piston neared TDC is how I know this isn't a real good plan. I've resorted to using a drink straw.
Oh, by the way, the 1/4" after TDC isn't critical just a long as it is at least 1/4". After you reach TDC on the compression stroke with the straw inserted put a mark on the straw about a 1/4- 1/2 inch above the head with a felt tip pen etc. and with a little pressure make the straw follow the piston on the power stroke as you rotate the flywheel / crank shaft in normal direction of engine operation. The pen mark on the straw will tell you about when to stop and adjust the valves.
pugaltitude
Lawn Addict
- Joined
- Jan 11, 2012
- Threads
- 7
- Messages
- 1,142
Plug out and valve cover off. screwdriver down plug hole.
Turn engine. Inlet valve open (should be bottom valve) piston down.
Inlet valve shuts piston coming up (compression).
Piston going back down (power).
On the power stroke just move piston down 1/4. Use the screwdriver to guess 1/4.
Set valves then turn engine 4 revolutions and check again.
Turn engine. Inlet valve open (should be bottom valve) piston down.
Inlet valve shuts piston coming up (compression).
Piston going back down (power).
On the power stroke just move piston down 1/4. Use the screwdriver to guess 1/4.
Set valves then turn engine 4 revolutions and check again.
EngineMan
Lawn Addict
- Joined
- Jun 12, 2012
- Threads
- 9
- Messages
- 2,275
In the first post he said..."Could someone give me specks on valve adj.on briggs 17.5 H.P.ohv.engine?"
I looked at B&S manual on 17.5hp and that is what it said....! if we had engine munber all the better....we all do cockup's..:confused2: and this one was mine.
He now has the right one's..........so that even better..:smile: