Hard to Start 16.5 hp Briggs V-TWIN

[Dave5264]

Hi guys, this past year the lawn Tractor has been getting harder and harder to start.

It will Crank over fine, but wont fire up very easily. IT can take 15-20 seconds or MORE of cranking to get it to fire up. (not good for the starter either)

Cranking it in shorter bursts-- it never starts

Once Running its fine.

I changed the Plugs,
cleaned the Air - Filter etc.
choke works fine
Fuel always has had stabil in it over the winter

its a 12 year old tractor with a "Commercial" 16.5 hp Briggs & Stratton V-TWIN

any ideas?

 

[Gator6x4]

Low compression? Check the engine compression when cold and hot. Some of the newer engines have a compression release feature that almost makes it impossible to get a accurate compression check. I don't know if your B/S engine is one of them.

 

[Dave5264]

Ill check it out.

no compression release on this one



thanks

 

[oldnslo]

Does it have the electronic ignition. For the age you are talking I would suspect it does. Check for good spark first.

If it has good spark then the compression test is next. Sounds like you may have some valves getting tight which will make engines harder to start.

NOTE: IF you have electronic ignition be sure that at least one of the plugs is always grounded. If not you may damage the ignition module.

Roy

 

[jinman]

I don't think your problem is electrical because electrical problems don't go away after 15 or 20 seconds of cranking. I think your problem is probably fuel related. I'd check:

1. Fuel filter for clogging
2. Fuel pump (remove hose at outlet and see if it flows when starting is attempted)
3. Carb varnished up and in need of cleaning internally
4. Flooding (This would be accompanied by the smell of fuel and vapors out the exhaust, maybe even white smoke when it finally starts.)

To check for fuel starvation, put a little gas into a hand-pump sprayer set for a solid stream. Take off the air cleaner and try to start the engine while spraying a small stream of fuel right into the intake throat of the carb. If the engine fires off, it's probably not getting fuel and the carb, fuel pump, or fuel filter need attention.

 

[oldnslo]

Low compession will also cause fuel starvation. I.e the motor does not create enough vacuum to draw the fuel mix into the engine.

Good thing to also check the fuel flow. Simplest check. Pull the fuel ine off at the carb. Hold over a contaner and turn the engine over.

If gravity feed do thesame thing to confirm the hose isn't partially plugged.

Roy

 

[biggerten]

Hi guys, this past year the lawn Tractor has been getting harder and harder to start.

It will Crank over fine, but wont fire up very easily. IT can take 15-20 seconds or MORE of cranking to get it to fire up. (not good for the starter either)

Cranking it in shorter bursts-- it never starts

Once Running its fine.

I changed the Plugs,
cleaned the Air - Filter etc.
choke works fine
Fuel always has had stabil in it over the winter

its a 12 year old tractor with a "Commercial" 16.5 hp Briggs & Stratton V-TWIN

any ideas?

They have a very good support site, lots of good info - Frequently Asked Questions | Briggs & Stratton

Look under "What would prevent an engine from starting". Scroll down to the bottom of that page for compression check and valve servicing info. Pretty cool site, better than the usual stuff manufacturers usually make available.

 

[b33b]

While it could be all of the above, I would try Jinman's suggestions first.

I have a 18hp Briggs that is hard to start if left too long (1-2 weeks). Cranks fine but no hint of firing until I add gas or ether to the carb intake. Then it runs fine and will restart until it sits a week or so.

Over the years I have replaced cracked fuel line sections, not enough to leak but leaking enough air to keep the weak carb fuel pump from pulling fuel from the rear tank. Also cleaned some crud on the pump's rubber diaphragm that helped starting for awhile. Now thinking of adding a pressure bulb, like you have on an outboard, to prime the line before cranking.

Good luck.

 

[zmaker]

Hi, We have a 35HP Briggs Vanguard that was next to impossible to start if left for more than a few days. After many discussions with mechanics, engineers, motorheads, and one really good Briggs and Stratton person, we put on an electric fuel pump. Solved the problem immediately. Seems our gas tank mounted under the engine was too low for the mechanical fuel pump to draw gas, if lines drained back from sitting. Shouldn't be too far, according to literature, but it is. (We used to solve hard starting problems back in the 60's by replacing mechanical fuel pump with Stewart Warner electric ones. Figured it should work today. It does.) Just our experience. Hope it helps someone.

 

[Dave5264]

It seems to be Fuel, spark and compression are good. Im told the fule pumps on these crp out frequently.

so ill clean the carb, put on new fuel lines and filter, and get a Fuel pump or a kit for it.

thanks guys