Export thread

14.5HP Briggs...sounds like starter but it isn't

#1

S

Smokeeater

I have a 14.5hp briggs (31R607-0011-G1) and it wants to start to turn over but it isn't completely. Well it did run a couple times but stalls or not at all now. The flywheel starts to turn but stops
-I thought starter but had it off and tested it and it's working fine.
-I isolated everything from battery (new) to starter and they're all working good
- I noticed when I try to turn the flywheel by hand it's a little hard at one point...so I took off the valve cover and made sure the valves were in adjustment right. I adjusted them to 0.004 intake and 0.006 exhaust, put it back together and nothing has changed.

Any thoughts?

Thanks!


#2

I

ILENGINE

Does the engine crank normally if you remove the spark plug. Also with the valve cover and spark plug removed rotate the engine by hand while watching the valves. the bottom valve should bump off seat shortly BTDC and then close which would indicate that the compression release is working. No bump would indicate that the release mechanism is broke and most likely laying in the sump of the engine.


#3

S

Smokeeater

What's bump off seat BTDC?


#4

Scrubcadet10

Scrubcadet10

The valve should open slightly just before the piston reaches the top of the bore. (Top Dead Center or TDC)
What's bump off seat BTDC?


#5

S

Smokeeater

The valve should open slightly just before the piston reaches the top of the bore. (Top Dead Center or TDC)
I know Top dead center...is the B for before?


#6

Scrubcadet10

Scrubcadet10

I know Top dead center...is the B for before?
yes


#7

S

Smokeeater

So after checking theses things...
-I removed spark plug and it cranks over no problem
-With cover off this is the sequence I see... Top intake valve opens and closes, as its closing the bottom exhaust moves, then there's a delay until that top valve starts to move again. In that delay time is where I find TDC and anywhere around that point of TDC no valve moves what so ever. Only valve movement is the intake, then right after the exhaust, delay (while turning by hand still) then the sequence starts again


#8

S

Smokeeater

Actually now that I look at what I did, I don't think I was on compression stroke when I found TDC.
I was just after Exhaust when it was up high showing through the spark plug hole...shoot maybe that's why
Intake/Compression/Power/Exhaust...I'll look for TDC after the Compression one and let you know


#9

S

Smokeeater

I adjusted them to spec after compression and at top but no change.
Here's an icloud link to a video of the valves moving. I got through 2 cycles and at the end I go back and forth. Does anyone see anything weird or missing? Like the "bump"
Valve Movement Link Here


#10

I

ILENGINE

I don't see the compression release bump, but it also looks like there may be too much clearance in the valves. May just be an illusion but just seems loose especially the intake/bottom valve


#11

T

Tinkerer200

I adjusted them to spec after compression and at top but no change.
Here's an icloud link to a video of the valves moving. I got through 2 cycles and at the end I go back and forth. Does anyone see anything weird or missing? Like the "bump"
Valve Movement Link Here

I am not able to access that link but if you don't see or feel that additional movement then the compression release is bad, quite common with this series engine.
Walt Conner


#12

S

Smokeeater

The lower rocker arm is really loose when closed and intake is moving. When I'm after compression stroke both aren't too bad and seem adjusted (see video)
I've seen where some people have found TDC on compression stroke and moved 1/4" in and others who have set the feeler guages to when say intake is all the way in and they set exhaust clearance. If I did it that way it is way off now
Video 2


#13

S

Smokeeater

I am not able to access that link but if you don't see or feel that additional movement then the compression release is bad, quite common with this series engine.
Walt Conner
Any videos of this "bump"? I'm trying to fond one on youtube to see what it is I'm missing


#14

S

Smokeeater

Ok I think I saw the bump on the lower valve, don't see it on mine. I adjusted the valves by fully closing one and adjusting other method and it didn't change.
Here's a video of a noise I'm hearing inside when I believe I'm supposed to see the bump
Bump Noise here


#15

S

Smokeeater

SOLVED

So I decided to drain the oil to see if anything came out...I put my telescoping magnet pen inside and cam out with these pieces that look like the compression pieces on cam and when you look inside the tube this piece was too big to come out

Anyone replaced a cam in one of these? (No oil filter)

Attachments







#16

I

ILENGINE

Changing the cam is no different without the oil filter than with one. Just without the oil filter you may not have to deal with the oil pump and driver even though they may use the same camshaft. Or some engines were set up with the pump but have a recirculating cap instead of the normal oil filter.


Top