# Briggs and Stratton 18HP V Twin overheating



## tm48827 (Oct 20, 2015)

I just swapped out a blown 19HP for a used 18HP that I was told ran strong. It does run well, but after 20 minutes it overheats. I am assuming it has something to do with the fact that this 18HP engine has a carb from a 20HP engine. The guy who sold me the engine said it was adjusted to the 18HP to maximize mid range power (at governed mowing RPMs). I hadnt heard of this, but he says he has done it many times for those tractors that need a little extra push... for tall grass or to use for pushing snow. He's had only good results. 

But wouldn't the potential problem of this combination be too much fuel? Iv'e read somewhere on this forum that overheating is caused by running lean fuel. The combustion from a lean fuel condition runs hot. Too much fuel usually causes engine to run cool. If I am not getting enough fuel, I considered that the carb solinoid might be going bad, restricting fuel. When I went looking for it, I didn't see it at the bottom of carb where I expected it to be. Instead the carb seems to tie directly into the exhaust. Im not familiar with this. Any ideas where I should start?


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## tm48827 (Oct 20, 2015)

I just found a reference to the soliniod: Briggs & Stratton P/N = 499809. Apparently this type doesnt screw into the bottom of carb like Im used to, but is the rectangular plate on front of carb. My plan tomorrow is to see if it is restricting my fuel.


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## TominDallas (Aug 4, 2015)

My personal experience with those solenoids is sometimes they get gunked up. A little gum can get inside the tube where the plunger slides back and forth, causing less than full travel and free movement. I've had them become so dirty the engine wouldn't run until it was cleaned. Cleaning it by soaking or spraying with carb cleaner would probably work. I've always disassembled them to clean. On engines I've had this problem with, they have always run better after it's clean.


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