OHV briggs hard to turn over - MyTractorForum.com - The Friendliest Tractor Forum and Best Place for Tractor Information

Packrat · 04-13-2012, 01:52 AM

I got a push mower with a 6.5hp ohv briggs. I was told its hard to turn over. I adjusted the valves to specs, easier to pull but still harder than it should be. If I rotate the engine by the blade, it turns easy, but use the pull rope while its on the compression stroke, and it almost feels like its jammed. Sometimes it will pull over normal, but it's unpredictable. Any ideas? The model # is 121601

daytona54 · 04-13-2012, 08:00 AM

did you adjust your valves at top dead center and on compression stroke ?........if so make sure your flywheel to engine shaft 'key' is not sheared,that would be the first thing i would check after valves adjusted.let us know about the key........i will continue to check back on your post to further assist.

38racing · 04-13-2012, 09:15 AM

Quote:

Originally Posted by daytona54

did you adjust your valves at top dead center and on compression stroke ?........if so make sure your flywheel to engine shaft 'key' is not sheared,that would be the first thing i would check after valves adjusted.let us know about the key........i will continue to check back on your post to further assist.

should be 1/4" past top dead centre

daytona54 · 04-13-2012, 10:30 AM

right you are 38racing...........I'd also check to see that the valves are seating properly

RED-85-Z51 · 04-13-2012, 10:47 AM

Make sure the blade is the right length, a short or worn blade lacks the inertia to help pass the engine through compression stroke.

RED-85-Z51 · 04-13-2012, 10:47 AM

Also be sure the brake is fully releasing on the flywheel, if its dragging intermittently, it will make pulling the rope ****.

rscurtis · 04-13-2012, 11:13 AM

Remove the valve cover (and spark plug wire!) and slowly turn the engine over with the blade. Watch the valves on the compression stroke for operation of the compression release. If you don't see it, it may need a new camshaft, or possibly just the spring on the compression release weight reconnected.

I once had a new Ryan LawnAireIV aerator with a 3.5HP Industrial Plus on it, it could rip the starter grip right out of your hand. All it was was the spring on the camshaft was not connected.

Packrat · 04-13-2012, 03:23 PM

Quote:

Originally Posted by daytona54

did you adjust your valves at top dead center and on compression stroke ?........if so make sure your flywheel to engine shaft 'key' is not sheared,that would be the first thing i would check after valves adjusted.let us know about the key........i will continue to check back on your post to further assist.

Yep. I don't think the key is sheared. It will start and run normally, just hard to pull.

Quote:

Originally Posted by 38racing

should be 1/4" past top dead centre

Quote:

Originally Posted by daytona54

right you are 38racing...........I'd also check to see that the valves are seating properly

Valves seem to seat ok. I had the head off to clean off any excess carbon build up. While it was off, I pushed on the valves to make sure they didn't sticking. They move freely and valve seat looks clean.

Quote:

Originally Posted by rscurtis

Remove the valve cover (and spark plug wire!) and slowly turn the engine over with the blade. Watch the valves on the compression stroke for operation of the compression release. If you don't see it, it may need a new camshaft, or possibly just the spring on the compression release weight reconnected.

I once had a new Ryan LawnAireIV aerator with a 3.5HP Industrial Plus on it, it could rip the starter grip right out of your hand. All it was was the spring on the camshaft was not connected.

Yeah looked for that. Didn't see it, but I'm not sure if it has a ACR or not. If it does, its not working. Was the spring damaged?

Fairway · 04-13-2012, 08:10 PM

I would venture to guess that he mechanical compression release is busted.

rscurtis · 04-13-2012, 08:38 PM

The spring was not damaged, just not connected when the engine was assembled. Never had a problem with it again.

04-13-2012, 01:52 AM	#1
Packrat Senior MTF Member Join Date: Aug 2008 Location: IL Posts: 189 MTF Member # 15571	OHV briggs hard to turn over I got a push mower with a 6.5hp ohv briggs. I was told its hard to turn over. I adjusted the valves to specs, easier to pull but still harder than it should be. If I rotate the engine by the blade, it turns easy, but use the pull rope while its on the compression stroke, and it almost feels like its jammed. Sometimes it will pull over normal, but it's unpredictable. Any ideas? The model # is 121601 __________________ 1984 Craftsman GT6000 with snowblower - Got it free 1966 Snowbird S-228 - Got it free 1971 Homelite S-8 - paid $30

04-13-2012, 08:00 AM	#2
daytona54 Senior MTF Member Join Date: Mar 2009 Location: fl. Posts: 157 MTF Member # 22907	Re: OHV briggs hard to turn over did you adjust your valves at top dead center and on compression stroke ?........if so make sure your flywheel to engine shaft 'key' is not sheared,that would be the first thing i would check after valves adjusted.let us know about the key........i will continue to check back on your post to further assist.

04-13-2012, 10:30 AM	#4
daytona54 Senior MTF Member Join Date: Mar 2009 Location: fl. Posts: 157 MTF Member # 22907	Re: OHV briggs hard to turn over right you are 38racing...........I'd also check to see that the valves are seating properly

04-13-2012, 10:47 AM	#5
RED-85-Z51 Certified Technician Join Date: Jul 2006 Location: Florida Posts: 7,637 MTF Member # 2950 Images: 7	Re: OHV briggs hard to turn over Make sure the blade is the right length, a short or worn blade lacks the inertia to help pass the engine through compression stroke. __________________ Owner/Operator of Hagrens Lawnmower Service and Repair Pensacola, FL Visit our site! http://hagrensmower.webs.com/ add us on facebook! https://www.facebook.com/HagrensLawnmowerService 1993 Wheel Horse 416-H Onan P216G 1962 WH702 1997 GMC Sierra C3500 Dually 454 Big Block "Vortec 7400" 4L80E 4.10 gears 1995 GMC Sierra K1500 Z71 350 TBI 4L60E Lifted 3", 33" tires True Duals/Thrush 3 chambers 3.42 gears

04-13-2012, 10:47 AM	#6
RED-85-Z51 Certified Technician Join Date: Jul 2006 Location: Florida Posts: 7,637 MTF Member # 2950 Images: 7	Re: OHV briggs hard to turn over Also be sure the brake is fully releasing on the flywheel, if its dragging intermittently, it will make pulling the rope **. __________________ Owner/Operator of Hagrens Lawnmower Service and Repair** Pensacola, FL Visit our site! http://hagrensmower.webs.com/ add us on facebook! https://www.facebook.com/HagrensLawnmowerService 1993 Wheel Horse 416-H Onan P216G 1962 WH702 1997 GMC Sierra C3500 Dually 454 Big Block "Vortec 7400" 4L80E 4.10 gears 1995 GMC Sierra K1500 Z71 350 TBI 4L60E Lifted 3", 33" tires True Duals/Thrush 3 chambers 3.42 gears

04-13-2012, 11:13 AM	#7
rscurtis 3K Poster!!!! Join Date: Apr 2009 Location: Pennsylvania Posts: 4,228 MTF Member # 25367	Re: OHV briggs hard to turn over Remove the valve cover (and spark plug wire!) and slowly turn the engine over with the blade. Watch the valves on the compression stroke for operation of the compression release. If you don't see it, it may need a new camshaft, or possibly just the spring on the compression release weight reconnected. I once had a new Ryan LawnAireIV aerator with a 3.5HP Industrial Plus on it, it could rip the starter grip right out of your hand. All it was was the spring on the camshaft was not connected.

04-13-2012, 08:10 PM	#9
Fairway Senior MTF Member Join Date: Jul 2011 Location: New Hampshire Posts: 146 MTF Member # 62828	Re: OHV briggs hard to turn over I would venture to guess that he mechanical compression release is busted. __________________ Ariens 924073 Ariens 10M6D 1972 Ariens Fairway 912003 RER. 1986 Toro 11/32 56170 RER. Tecumseh TVM195 Tecumseh LH195SP Tecumseh H60 Tecumseh HSK70 Tecumseh HMSK90 Tecumseh HM100 Tecumseh HMSK100 Briggs & Stratton 130202 Briggs & Stratton 190412 Subaru SP170

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04-13-2012, 08:38 PM	#10
rscurtis 3K Poster!!!! Join Date: Apr 2009 Location: Pennsylvania Posts: 4,228 MTF Member # 25367	Re: OHV briggs hard to turn over The spring was not damaged, just not connected when the engine was assembled. Never had a problem with it again.

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