i've got an older fh500v that started knocking this summer. i didnt have time to open the case so i just ran it, and it didnt really get any worse after a certain point. it seems to only knock when its under a heavy load, worse when cold. theres certain engine speeds where it wont make any noise at all and it sounds perfect. it almost sounds like a really deep pitched rattle and you definitely cant miss it. so i split the case open and i expected to have the problem be really obvious but everything inside seems pretty decent. theres some obvious wear to the governor. the connecting rods seem to be a little loose but i cant imagine their loose enough to make the sound it was making since it was intermittent. the main bearings are tight, but the crankshaft did have a bit of up and down endplay, will a crank bounce up and down under the right conditions and make a knock? any ideas?
A certain amount of endplay is normal, you don't want too much, or the crank can " bounce" around a little. I would be more concerned with the piston to cyl. fit/wear. Did you check it ? Sounds like piston rap/knock/slap, " worse when cold" are the key words here! You need to check everything and compare to the specs.
The rods should be snug. Look for metal transfer on the sides of the rods where they ride against each other on the crank. Also look at the machined rod bearings that ride on the crank. If all looks good. Remove the wristpin and look for any dull spots where it rides in the piston. Posted via Mobile Device
do you think its possible the fork connected to the governer shaft bouncing through those grooves could cause that plate to rattle?
If all the bearing surfaces are good. Look at the gears with a magnifying glass ( if you're old like me) Look for any wear patterns. On the cam it will show up on 3 to 7 teeth in a row if the gears are causing the knock. Posted via Mobile Device
looks as if you are missing snap ring on gov shaft , also looks as if you have abnormal wear on washer should be cln, gov ball plate looks like has dents in it or is that shadows. also pull cone and chk for wear marks where plate touches gov balls
looking at cyl head looks as if you have top end leak. major prob. at my shop will overheat everything
i had someone with a little more knowledge than me look at this engine. crank main bearings are near perfect, we took the caps off the connecting rods and their near perfect, the pistons skirts still have machining marks on them are their tight in the bore. in the picture there's a snap ring and washer removed, they aren't missing. the only thing that seems wrong with this engine is the governor surface where its pitted out. so as of right now it looks like i might get by pretty cheap with a base gasket and some governor parts.
