This is an old unit that was sitting outside that I am trying to repo. I got the gas tank all cleaned out and replaced carb with one off unit that was working. The carb was ultrosonic cleaned. I got the unit to start and run for a little bit a couple times. I was not getting gas and I am waiting for parts. In the meantime I thought I would check and adjust valve clearance before I proceed but.......according to the manual there doesn't seem to be any adjustment except grinding the tappet? So if I take the little cover off behind the carb and find that the clearance are out of spec I will have to pull the Head?
Kawaski FB460V Starting Problem
ed2hess
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This is an old unit that was sitting outside that I am trying to repo. I got the gas tank all cleaned out and replaced carb with one off unit that was working. The carb was ultrosonic cleaned. I got the unit to start and run for a little bit a couple times. I was not getting gas and I am waiting for parts. In the meantime I thought I would check and adjust valve clearance before I proceed but.......according to the manual there doesn't seem to be any adjustment except grinding the tappet? So if I take the little cover off behind the carb and find that the clearance are out of spec I will have to pull the Head?
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10 4.....just like a 5 hp briggs...only bigger....
Take a good look at the valve guides...they like to slip on high hour engines..
If so...tap them back in place...or get a long 1/4 bolt ..nut..and washers..and pull it back into place..
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Take a good look at the valve guides...they like to slip on high hour engines..
If so...tap them back in place...or get a long 1/4 bolt ..nut..and washers..and pull it back into place..
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Ok I can check that if I pull the head off. So your experience says to forget about valve clearance because that isn't usually a problem? The final attempt to start the unit with quick start resulted in a backfire. That damaged one of the recoil pawls so... I am getting parts for that but don't think I want to retry if I got a valve problem. So you recommend to pull it apart!
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Ed,
Sounds like you do have a valve issue be it bad/carboned valve faces/seats or a guide as Slapper mentioned.
You can check valve specs without pulling the head but to adjust the valves you have to pull the head and remove the valves, At this point you can check the guides and valve/seats for wear and carbon.
Never grind the tappets to adjust valves, That is wrong and would require the sump/pan and cam removal. Always grind the valve stems to adjust clearances.....
I'd be willing to bet, Since the engine has set up the carbon on the head/piston dried out. Soon as you put fuel through it the dried carbon broke loose and got stuck under the valves, Seen this many many times......
Sounds like you do have a valve issue be it bad/carboned valve faces/seats or a guide as Slapper mentioned.
You can check valve specs without pulling the head but to adjust the valves you have to pull the head and remove the valves, At this point you can check the guides and valve/seats for wear and carbon.
Never grind the tappets to adjust valves, That is wrong and would require the sump/pan and cam removal. Always grind the valve stems to adjust clearances.....
I'd be willing to bet, Since the engine has set up the carbon on the head/piston dried out. Soon as you put fuel through it the dried carbon broke loose and got stuck under the valves, Seen this many many times......
Thanks Slapper and Rob I will just go ahead and pull the head. I bought this unit for $40 from a lawn business. It was in his back yard with weeds so high you could hardly see the unit. I robbed one of the spindles to put in my Wright Sentar and that worked fine after I did some grinding.
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Ed...remove the carb and the sidecover and check your clearances..
With any engine that's been sitting out in the weather for years...its always a good idea to pull the head to get an idea of how it was running before it was parked..
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With any engine that's been sitting out in the weather for years...its always a good idea to pull the head to get an idea of how it was running before it was parked..
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I took the valve cover off and the intake measured at least .002" and I can almost get a .0015" in the exhaust but not sure. I don't have smaller gage.
I guess I was expecting the exhaust to be wider because I was assuming there was debris on the seat.
Now what next? I got a leak tester.
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The valves are too tight....the valve faces are worn into the seats...
Pull the heads and do a valve job...see if you can pick up a cheap set of feeler gauges...you're gonna need them...
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Pull the heads and do a valve job...see if you can pick up a cheap set of feeler gauges...you're gonna need them...
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I got the head off and the exhaust valve has a pretty big cup shape on it the intake looks better. Probably will have to get new valve.
And there is a bad looking mark on the cyclinder where that head was parked for months or years. It isn't rough to touch but will need to be addressed. Probably means new rings.
I think it is time to pull the engine off the mower. If it was a Kohler I would lap those valves and try it but this seems to be a more complicated setup.
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Take the valves to your local automotive machine shop, They can be re-faced then extra taken off the stems to get back to proper valve clearance specs....
My local NAPA only charges us 2 bux each....
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Ed...the FB460 is the toughest engine ever put on a mower...
The piston rings are thicker than any other mower engine...
Try this...grind the valve stems to get the right clearances...
Lap the valves to reseat them...without grinding the valves or seats.
Clean up the mark in the cylinder...and reassemble...
It'll run good...maybe another 300 to 500 hours...
Those engines are very forgiving...
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The piston rings are thicker than any other mower engine...
Try this...grind the valve stems to get the right clearances...
Lap the valves to reseat them...without grinding the valves or seats.
Clean up the mark in the cylinder...and reassemble...
It'll run good...maybe another 300 to 500 hours...
Those engines are very forgiving...
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Everything on this engine looks like a quality engine. If you grind the stems and check witout the spring on how close is that? I am saying if I grind it and the clearance checks .003 how much does it change with spring on?
I will do exactly what you suggest.....Thanks.....
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The clearance should be the same with or without the spring...
Here's how I do it....
I lap the valves first...you have to have some clearance between the valve and the tappet or the tappet will hold the valve off the seat...it won't lap in..
Once they are lapped in..the valves should be hard to turn when pushing it against the seat...after you wipe the lapping compound off..of coarse...
If they spin easy...lap them again...
Get the right feeler gauge and turn on your bench grinder..
Grind a little at a time off the stem...checking clearance between each grind.
When the clearance is right..the valve will not spin when pushed against the seat..Be patient...you can't put back on...what you grind off..
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Here's how I do it....
I lap the valves first...you have to have some clearance between the valve and the tappet or the tappet will hold the valve off the seat...it won't lap in..
Once they are lapped in..the valves should be hard to turn when pushing it against the seat...after you wipe the lapping compound off..of coarse...
If they spin easy...lap them again...
Get the right feeler gauge and turn on your bench grinder..
Grind a little at a time off the stem...checking clearance between each grind.
When the clearance is right..the valve will not spin when pushed against the seat..Be patient...you can't put back on...what you grind off..
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Got the valves out and the exhaust is worn into a cup shape so I will have to replace it. With the springs off the exhaust had no clearance so that was one problem. So when I get the new valve I will lap it against the seat. Is there any chance in hell that there could be too much wear on that exhaust tappet and with the new valve the clearnce would be wide?
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Hate to see what they want for a new valve...
Don't worry...you're gonna have to grind a little to get your clearance..
Just for kicks...grind a little off the ex valve stem and see if you can get it to seat.
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Don't worry...you're gonna have to grind a little to get your clearance..
Just for kicks...grind a little off the ex valve stem and see if you can get it to seat.
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Another great idea........$44 for exhaust valve. And if nothing else it give me some practive. By the way what is your opinion on putting on a new head gasket and replacing the bolts? The gasket came off like it was almost new.
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Ed...let me qualify this...The procedures I am describing in this thread are for the purpose of spending as little time and money to get an engine with unknown problems running...once you get it running you can determine how much work needs to be done...for all you know it could have a knocking rod or synchro...
Re use the head gasket and fire it up....
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Re use the head gasket and fire it up....
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Ok I understand what you mean.
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The rotator rotates the exh valve to prevent the valve from overheating.
If it doesn't turn..the side of the valve face closest to the exhaust port will get hotter and warp or burn up the valve..
Just find a bolt long enough to go through the guide and some washers...
Tighten the bolt to draw the guide back into place..
Make sure to de burr the guide so the valve moves freely...
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If it doesn't turn..the side of the valve face closest to the exhaust port will get hotter and warp or burn up the valve..
Just find a bolt long enough to go through the guide and some washers...
Tighten the bolt to draw the guide back into place..
Make sure to de burr the guide so the valve moves freely...
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