lawn tractor engine: how do i check to see if the valves are seated properly?

Question

my engine gets loaded easily, like when mowing a lawn while driving up an incline. ive tried all the simple remedies to try and improve the power- swapped out carbs from my old engine, new air filter, new fuel filter, new fresh fuel lines- but nothing seems to be working.

some people have said that the valves may not be seated properly. how to i check to see if this is the problem? what should i look for and how do i correct it?

my engine is a B&S 17.5hp, OHV, single cylinder; Craftsman I/C model

whats driveline and transfer case? i dont have a a lot of mechanical experience, so please speak simple.
i have a gear transmission so there is no fluid in it (i think). should i check the drive belt tension?

i havent messed with the valves. i took the cover off my old engine just to see what it looked like. i dont want to mess around with that kind of stuff unless i know its causing the problem.
not to mention oil would flow everywhere.

Answer 1

Epic,
Check your belts. One may be on the wrong side of a belt guard. (thats a piece of metal designed to keep the belt in a pulley and not jump out) they are located right at the pulleys. It is easy to overlook something like this! It will make the engine 'bog down' quickly. Sometimes the belts will squeal and smoke too.
Hope this helps!
B

Answer 2

Sounds like to me that you may have a fuel problem?..not only that, but you said going up an incline?...check and make sure your oil is properly filled...I have a problem thinking it's your valves not being seated properly, unless you have been working on the engine?...will tell you this..just pulled up a shcematic of the engine and the carb.? Hope you had the same kind of engine as there are two different carbs that can go on this particular engine..with out your model type and code..I don't know.....again, depends on which one you have...
Doesn't sound like your valves aren't properly seated...these are overhead valves...have you been messing with them? I believe the clearance on them is .003-.005..Hope you haven't been messing with them...

Answer 3

This is a long shot but when you changed engines did you use the same pulley on the engine or the one that was on the new engine? Check to see that they are the same size. Changing that pully size would effect the power. As for the valves you have to remove the valve cover and use a feeler guage to check clearance. Most likely .003-.005 inches cold. If this is the same engine that was on the utube video, it still sounded like a fuel issue to me.

Answer 4

I agree with possible driveline issues ( pulleys, belts, transmission fluid) . The tractor should use the stock motor pulley , definitly make sure the trans has fluid in it ( if its the kind you can add- theres screw in plugs in the actual transmission) , belt slippages ( has enough tension on it - or if too worn will just slip). Check those first and see if it improves.
Kidd

Answer 5

id take a look at the driveline,transfer case, etc. make sure they all have the proper fluid levels in them. if the engine seems to run fine when standing still this could be your issue.