All-Terrain Lawn Tractor Forum
Would you like to react to this message? Create an account in a few clicks or log in to continue.

All-Terrain Lawn Tractor Forum

Like riding lawn tractors through mud, woods, rocks, and snow? Then this is the place for you! Share your ideas, Post your projects and more!
 
PortalHomeSite RulesEventsFAQSearchRegisterLog inBuild-Off

 

 15.5hp OHV Compression Issues

Go down 
+2
TheRainbowBoxer
BlackMountian88
6 posters
AuthorMessage
BlackMountian88
Member
BlackMountian88
Member


Age : 25
Join date : 2012-09-08
Points : 4845
Posts : 399
Location : NH

15.5hp OHV Compression Issues Empty
PostSubject: 15.5hp OHV Compression Issues   15.5hp OHV Compression Issues Icon_minitimeFebruary 14th 2013, 2:02 pm

Hello.
I need some quick help with my 15.5hp OHV Briggs&Stratton "Turbo Cool" (like me Cool ) Lawn mower engine that has excessive compression. My electric start wouldn't turn the thing over, so I tried it by hand an I couldn't spin it.
I read something about ACR, and valve clearance, but I have no idea how that relates to OHVs.
I'm about to take it apart, so I'll update you guys with what I find.

Thanks a lot!
Back to top Go down
TheRainbowBoxer
Moderator
TheRainbowBoxer
Moderator

1000+ Posts
1000+ Posts!

Age : 49
Join date : 2012-04-23
Points : 5653
Posts : 1091
Location : Galion, OH

15.5hp OHV Compression Issues Empty
PostSubject: Re: 15.5hp OHV Compression Issues   15.5hp OHV Compression Issues Icon_minitimeFebruary 14th 2013, 2:48 pm

Does it turn hard with the plugs out? If so, there is some bottom end issues.


Proud member of the Mower Cycle Gang... aka the "Mowrons!"

My build (Chaos is one of 3 built like this)
Chaos Build

The Mower Cycle Gang visited 1puglife in May 2014
Check out the pics and vids!

Haspin 2021 was a blast!  Check out pics and vids here
Haspin 2021 thread

Join us for the annual Mowron-fest at Haspin Acres!
Haspin Acres Rally 2022!

Check out my YouTube for more tractor action, my vlog, and my bus build!
TheRainbowBoxer on YouTube
Back to top Go down
BlackMountian88
Member
BlackMountian88
Member


Age : 25
Join date : 2012-09-08
Points : 4845
Posts : 399
Location : NH

15.5hp OHV Compression Issues Empty
PostSubject: Re: 15.5hp OHV Compression Issues   15.5hp OHV Compression Issues Icon_minitimeFebruary 14th 2013, 3:26 pm

Ah ha, see I didn't check. I took the head assembly off without taking the plug out! Stupid.
I do need a new head gasket, a whole load of oil poured out of the cylinder when I opened it.
Anything I should check?
Back to top Go down
TheRainbowBoxer
Moderator
TheRainbowBoxer
Moderator

1000+ Posts
1000+ Posts!

Age : 49
Join date : 2012-04-23
Points : 5653
Posts : 1091
Location : Galion, OH

15.5hp OHV Compression Issues Empty
PostSubject: Re: 15.5hp OHV Compression Issues   15.5hp OHV Compression Issues Icon_minitimeFebruary 14th 2013, 3:27 pm

If it was sitting upside down for a while oil may have just seeped in. Otherwise you might need rings. Oil in the cylinder would definitely make it hard/impossible to turn over.


Proud member of the Mower Cycle Gang... aka the "Mowrons!"

My build (Chaos is one of 3 built like this)
Chaos Build

The Mower Cycle Gang visited 1puglife in May 2014
Check out the pics and vids!

Haspin 2021 was a blast!  Check out pics and vids here
Haspin 2021 thread

Join us for the annual Mowron-fest at Haspin Acres!
Haspin Acres Rally 2022!

Check out my YouTube for more tractor action, my vlog, and my bus build!
TheRainbowBoxer on YouTube
Back to top Go down
BlackMountian88
Member
BlackMountian88
Member


Age : 25
Join date : 2012-09-08
Points : 4845
Posts : 399
Location : NH

15.5hp OHV Compression Issues Empty
PostSubject: Re: 15.5hp OHV Compression Issues   15.5hp OHV Compression Issues Icon_minitimeFebruary 14th 2013, 3:31 pm

No It's been in the mower all the time.

It's OHV so I can see the gasket part between the push rod hole thingy and the cylinder, and It's corroded.
Back to top Go down
BlackMountian88
Member
BlackMountian88
Member


Age : 25
Join date : 2012-09-08
Points : 4845
Posts : 399
Location : NH

15.5hp OHV Compression Issues Empty
PostSubject: Re: 15.5hp OHV Compression Issues   15.5hp OHV Compression Issues Icon_minitimeFebruary 14th 2013, 5:06 pm

Would that solve high compression? An oil leak?
Back to top Go down
Chopperhed
Moderator
Chopperhed
Moderator

500+ Posts
500+ Posts

Age : 58
Join date : 2012-10-14
Points : 5206
Posts : 801
Location : Edmonton, Alberta, Canada Eh!

15.5hp OHV Compression Issues Empty
PostSubject: Re: 15.5hp OHV Compression Issues   15.5hp OHV Compression Issues Icon_minitimeFebruary 14th 2013, 5:43 pm

BlackMountian88 wrote:
Would that solve high compression? An oil leak?

all lot of extra oil in the cylinder will usually cause the engine to lock up completely.

A slight amount of extra oil will increase compression briefly, especially in a worn engine.

One of the procedures when doing a compression test is to squirt some oil in the plug hole and see if the compression increases.

If it does, the rings are shot. If compression does not increase valves are toast.
Back to top Go down
http://http:\\members.shaw.ca\ducksgarage
BlackMountian88
Member
BlackMountian88
Member


Age : 25
Join date : 2012-09-08
Points : 4845
Posts : 399
Location : NH

15.5hp OHV Compression Issues Empty
PostSubject: Re: 15.5hp OHV Compression Issues   15.5hp OHV Compression Issues Icon_minitimeFebruary 14th 2013, 5:58 pm

Ok, so weather the pressure increases, or decreases when oil was added there is something wrong?

But I will probably blame the acess pressure on the oil. I'm going to put it back together tomorrow (If I can salvage the head gaske) and see what happens. Thanks!
Back to top Go down
Chopperhed
Moderator
Chopperhed
Moderator

500+ Posts
500+ Posts

Age : 58
Join date : 2012-10-14
Points : 5206
Posts : 801
Location : Edmonton, Alberta, Canada Eh!

15.5hp OHV Compression Issues Empty
PostSubject: Re: 15.5hp OHV Compression Issues   15.5hp OHV Compression Issues Icon_minitimeFebruary 14th 2013, 7:26 pm

The procedure for a proper compression test
Warm up the engine if possible

Remove all spark plugs and ground the coil(s)

Open the throttle wide open (no choke), fuel off

Install a compression gauge in a plug hole and crank the engine untill the gauge needle stops climbing.

This is your dry compression reading.

If the compression is low, then add a bit of oil to the cylinder, and re check compression,

If compression increases, the rings are shot.
If no increase in compression, valves are shot.

This is your wet compression reading,

Back to top Go down
http://http:\\members.shaw.ca\ducksgarage
Marines2621
Member
Marines2621
Member


Age : 27
Join date : 2012-12-31
Points : 4535
Posts : 215
Location : Mountainburg, Arkansas

15.5hp OHV Compression Issues Empty
PostSubject: Re: 15.5hp OHV Compression Issues   15.5hp OHV Compression Issues Icon_minitimeFebruary 14th 2013, 8:13 pm

Dont forget. You can also back the valves off alittle to start easier
Back to top Go down
BlackMountian88
Member
BlackMountian88
Member


Age : 25
Join date : 2012-09-08
Points : 4845
Posts : 399
Location : NH

15.5hp OHV Compression Issues Empty
PostSubject: Re: 15.5hp OHV Compression Issues   15.5hp OHV Compression Issues Icon_minitimeFebruary 15th 2013, 8:23 am

Ok I kinda get it. Thanks.

I've never taken an OHV apart so I don't know how to back the valves out. Razz
Back to top Go down
ibdalovely1
Member
ibdalovely1
Member

2014 Build-Off Entrant
2014 Build-Off Entrant

Age : 45
Join date : 2012-12-27
Points : 4419
Posts : 92
Location : dayton ohio

15.5hp OHV Compression Issues Empty
PostSubject: Re: 15.5hp OHV Compression Issues   15.5hp OHV Compression Issues Icon_minitimeFebruary 15th 2013, 8:33 am

the murray i just got had a similar issue its a 15.5 ohv the valves were not adjusted correctly and would not let it turnover fast enough to start ive got a vid up on my channel on how to adjust them
Back to top Go down
BlackMountian88
Member
BlackMountian88
Member


Age : 25
Join date : 2012-09-08
Points : 4845
Posts : 399
Location : NH

15.5hp OHV Compression Issues Empty
PostSubject: Re: 15.5hp OHV Compression Issues   15.5hp OHV Compression Issues Icon_minitimeFebruary 15th 2013, 8:43 am

Excellent vid, what size gap did you use?
Back to top Go down
ibdalovely1
Member
ibdalovely1
Member

2014 Build-Off Entrant
2014 Build-Off Entrant

Age : 45
Join date : 2012-12-27
Points : 4419
Posts : 92
Location : dayton ohio

15.5hp OHV Compression Issues Empty
PostSubject: Re: 15.5hp OHV Compression Issues   15.5hp OHV Compression Issues Icon_minitimeFebruary 15th 2013, 10:15 am

.004 i didnt put it in the vid because different motors are different gaps usually they are set at 2 different sizes but all the vids i have watched set them at the .004 gap for both i/e
Back to top Go down
Chopperhed
Moderator
Chopperhed
Moderator

500+ Posts
500+ Posts

Age : 58
Join date : 2012-10-14
Points : 5206
Posts : 801
Location : Edmonton, Alberta, Canada Eh!

15.5hp OHV Compression Issues Empty
PostSubject: Re: 15.5hp OHV Compression Issues   15.5hp OHV Compression Issues Icon_minitimeFebruary 15th 2013, 11:15 am

normally exhaust valves are set a little wider to allow for extra expansion
Back to top Go down
http://http:\\members.shaw.ca\ducksgarage
BlackMountian88
Member
BlackMountian88
Member


Age : 25
Join date : 2012-09-08
Points : 4845
Posts : 399
Location : NH

15.5hp OHV Compression Issues Empty
PostSubject: Re: 15.5hp OHV Compression Issues   15.5hp OHV Compression Issues Icon_minitimeFebruary 15th 2013, 11:33 am

Ok. I can probably google the factory specs.

I did check and the rockers where no where near that wobbley. I will check the gapping tho.
Back to top Go down
crafsmankiller
Member

Member


Age : 26
Join date : 2012-10-18
Points : 4845
Posts : 412
Location : livingston texas

15.5hp OHV Compression Issues Empty
PostSubject: Re: 15.5hp OHV Compression Issues   15.5hp OHV Compression Issues Icon_minitimeFebruary 15th 2013, 12:56 pm

did it run before you had the problem? what i did to re-seat my valves is, loosen up the nuts holding the rockers and re-tighten them down just enough to were the rockers dont easily move by hand. i did this and it fixed my problem, but, like evry1 else said, it could be the rings.
Back to top Go down
BlackMountian88
Member
BlackMountian88
Member


Age : 25
Join date : 2012-09-08
Points : 4845
Posts : 399
Location : NH

15.5hp OHV Compression Issues Empty
PostSubject: Re: 15.5hp OHV Compression Issues   15.5hp OHV Compression Issues Icon_minitimeFebruary 15th 2013, 1:39 pm

WHOO Just ran it! Felt so good to be out again!

Yes it ran before, but it sat for almost a month.

I took the whole head apart aside from taking the valves out. Cleaned oil out of the cylinder, and Re-gapped the rockers, and put it all together.
Started first turn!

Now I just have to clean the carb (it only runs full choke).
Back to top Go down
ibdalovely1
Member
ibdalovely1
Member

2014 Build-Off Entrant
2014 Build-Off Entrant

Age : 45
Join date : 2012-12-27
Points : 4419
Posts : 92
Location : dayton ohio

15.5hp OHV Compression Issues Empty
PostSubject: Re: 15.5hp OHV Compression Issues   15.5hp OHV Compression Issues Icon_minitimeFebruary 15th 2013, 1:47 pm

good stuff glad you got it running again
Back to top Go down
BlackMountian88
Member
BlackMountian88
Member


Age : 25
Join date : 2012-09-08
Points : 4845
Posts : 399
Location : NH

15.5hp OHV Compression Issues Empty
PostSubject: Re: 15.5hp OHV Compression Issues   15.5hp OHV Compression Issues Icon_minitimeFebruary 15th 2013, 1:50 pm

Thanks for the help!

I'll have to post a pic of it now: stuck in a snowbank. Smile
Back to top Go down
BlackMountian88
Member
BlackMountian88
Member


Age : 25
Join date : 2012-09-08
Points : 4845
Posts : 399
Location : NH

15.5hp OHV Compression Issues Empty
PostSubject: Re: 15.5hp OHV Compression Issues   15.5hp OHV Compression Issues Icon_minitimeFebruary 23rd 2013, 2:10 pm

AHHHH! It did it again. It ran out of gas, so I took like a minute to fill it up again, flipped the switch, and the motor whined and didn't run over. Probably needs a new head gasket and rings. Such a new engine tho. Now I'm considering selling the tractor to pay for my 4 cyl project. Humph. Sad
Back to top Go down
Sponsored content





15.5hp OHV Compression Issues Empty
PostSubject: Re: 15.5hp OHV Compression Issues   15.5hp OHV Compression Issues Icon_minitime

Back to top Go down
 
15.5hp OHV Compression Issues
Back to top 
Page 1 of 1
 Similar topics
-
» got bad compression?
» Raising Compression Briggs 12.5 HP
» Briggs 14.5 high compression problems
» Briggs 12HP Compression Leak?
» Has anyone removed compression release on their lawnmower engines?

Permissions in this forum:You cannot reply to topics in this forum
All-Terrain Lawn Tractor Forum :: Technical Forum :: Engine Tech :: Briggs and Stratton-
Jump to: