Briggs 15.5 intek

Shakeandbake · Feb 28, 2023

Hello guys. I inherited a riding mower with a 15.5 Briggs intel engine. It wasn t running so I replaced carb. Replaced blown. Head gasket. Adjusted valves. Replaced battery. Replaced mower deck pulleys. Fuel filter and lines. It fires right up no problem. Idles perfect, no surging etc. the problem I noticed when I used it for the first time under load, to mow the lawn this weekend is that once the blades are engaged and cutting the engine seems to slow down and it almost feels like it s loosing a good amount of power and sounds different. When I disengage the blades it goes back to sounding perfect and idling as it should. Never had one of these mowers so I don t know if it s normal for it loose that much power under load or is there something o need to adjust. Thanks in advance.

This post was edited by Shakeandbake on 02/28/2023 at 05:37 pm.

J Hamilton · Feb 28, 2023

First of all, what kind of mower? Tractor type or zero turn? Also, I would take the belts off the deck and spin all pulleys and blade spindles by hand to be sure they all turn free and smooth.

Shakeandbake · Feb 28, 2023

hello, it s a mTD 42 inch riding mower. All the pulleys for the cutting deck have been replaced and spin good. Not sure if I might have adjust the carb to make up for under load condition?

J Hamilton · Feb 28, 2023

Did you also check the blade spindles to be sure they spin free and there isn't something wrapped around the bottom of the shaft around the blades? Most MTD mowers had a small brake on the spindle pulleys, if they aren't broken off or worn out, be sure they are released when blades are engaged.

Shakeandbake · Feb 28, 2023

it s my first time ruining it since I rebuke the deck. I took blades off and replaced the spindles whiskies I was at it. I know what small brake pads your talking about. I ll have to double check to make sure they release when the blades are engaged. You might be on to something. I ll give it a look.

Steve@Advance · Mar 2, 2023

When you engage the blades, watch the action of the throttle linkage on the carb.

It should instantly go to full open throttle until the engine comes up to speed.

If the throttle plate does not fully open, there is an adjustment problem with the governor linkage.

If the throttle does fully open, but the engine does not respond, there may be a jetting problem, or something is binding in the mower deck. If something is binding it will show as a overheating spindle, a slipping, smoking belt, etc.

Replacement carbs are commonly not exactly right as far as linkage or jetting, Compare it closely to the original as for physical similarity, especially the throttle linkage. If there is a performance problem, compare the jet size. A properly jetted carb will go from slow idle to quickly applied full throttle without hesitation.

Shakeandbake · Mar 2, 2023

so I started it up and it was idling perfect. As soon as I engage the blades I noticed the governor arm starts going crazy. It s flip flops like crazy and starts running rough. As soon as I disengage the blades it idles perfect again and the governed arm doesn t spaz out, it remains steady. As soon as I try to put any kind of load I d starts making the governor go crazy side to side again.

Briggs 15.5 intek

Shakeandbake

New User

J Hamilton

Well-known Member

Shakeandbake

New User

J Hamilton

Well-known Member

Shakeandbake

New User

Steve@Advance

Well-known Member

Shakeandbake

New User

Similar threads