D160 not cutting very well

[Deleted member 97405]

Quality of cut is all about air flow. Gator blades don't create enough lift in certain grass types because the wing tips are serrated, which decreases air flow. The discharge chute is also choking the air flow. Put a new chute on it, OEM side discharge blades (or OEM mulch blades if running a mulch kit), set your high rpm at/about 3300, level the deck, and you should be good. I've seen this issue many times over the years, and this has 100% fixed everyone of them.

 

[PTmowerMech]

I can understand liking the Gator type blades for leaves. A deck leveling adjustment and raising the RPMs will help some.

3100 RPM (fast idle) is too low for a Briggs V twin?

 

[MParr]

3100 RPM (fast idle) is too low for a Briggs V twin?

Exactly. At 3600 they develop peak horsepower. Peak torque comes in around 3100. This is according to Briggs and Stratton. However, try 3300 RPMs and see how it cuts. You certainly don’t want to have your customer blow an engine straight out of your shop.
What @Will1988 said about the Gator type blades is true. The only time adequate lift is achieved with Gator type blades is when running the G6 commercial blades. The JohnDeere GX21786 mulching blades would perform better than the Gator type blades. Just add the JD composite chute blocker.
By all means fix the discharge chute.

 

[slomo]

If you are trying to bag or on leaf patrol, max revs is the ticket. Crank her up to 3600 and never look back.

 

[PTmowerMech]

something kept bugging me about the way the engine ran on PTO start up. It just sounded a little off. So while turning the idle screw in to get higher RPM's, I got to noticing the springs on the back side of the linkage bracket, At fast idle, the bottle spring (the smaller one) was loose, regardless of fast or slow idle. So I put the idle screw back to it's original position, and tweaked the governor bracket, to increase RPM's to 3350. The spring tightened up at fast idle.

So I mowed another round, and it seems that fixed the problem. I'm going to leave it at 3350, at least until spring when I put the high lift blades on it. 3600 scares me. LoL..

BTW, the deck chute, to get it up higher, will have to rigger nigged to get it up any higher. Maybe some sort of plate screwed onto the deck where the chute rests, to get it up some more. It's stock. So it's where it's supposed to be, minus what little wear there is.

 

[slomo]

Plasma cutter and a TIG welder. Good to go.

 

[Deleted member 97405]

yes, DO NOT raise the rpms to 3600. I will debate anyone who recommends this! You will blow your engine. That rpm is too fast for the oil to provide adequate lubrication on the aluminum connecting rods against a steel crankshaft, not to mention cam lobes, pushrods, and valve spring abuse from over-revving. Ask me how I know! Something about zinc, but I digress. I'm glad you decided to keep it around 3350. Good luck. I hope that fixes it for you.

 

[PTmowerMech]

yes, DO NOT raise the rpms to 3600. I will debate anyone who recommends this! You will blow your engine. That rpm is too fast for the oil to provide adequate lubrication on the aluminum connecting rods against a steel crankshaft, not to mention cam lobes, pushrods, and valve spring abuse from over-revving. Ask me how I know! Something about zinc, but I digress. I'm glad you decided to keep it around 3350. Good luck. I hope that fixes it for you.

According to this, the 875 series is to be ran at 3600 RPM's. But I'm not sure what series this Briggs 44S977-0026G1 is.

 

[Scrubcadet10]

blades not upside down are they?

 

[MParr]

This link takes a little long to load. Look on page #23. Your particular engine is not listed. The reason for that is John Deere has a special model number for their Briggs supplied engines.

https://www.briggsandstratton.com/content/dam/briggsandstratton/na/en_us/Files/FAQs/2016_RepowerEngineSpecs.pdf