Lawn Care Forum banner
1 - 5 of 5 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter · #1 ·
Hi, i'm having issues with the valves on my ztrak 920a. After replacing one of the cylinder heads because one of the valve guides had moved and one of the push rods was bent. I fitted new push rods and set the gap between valves and rocker guides at .05mm to .10mm. The machine ran well for about an hour and a half and then i heard a ping and the engine lost power. It was only firing on one cylinder. After taking off the rocker cover i noticed one push rod had come out of place. I noticed that the gap between valve and rocker was very big and measured at .15mm. All the bolts on the rockers were tight. I did notice that the rocker arms seem to have wear (refer attached photos). I assume that the rocker where the push rod came out could have had the same gap. I set everything up previously to the JD technical manual. Any ideas why i could habe got such big gaps after only an hour and half of running. PS i am going to check the gaps on the good cylinder to see if they are ok or are excessive the same as the bad side.
Gas Auto part Fixture Metal Machine
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #3 ·
Kawasaki fx730v. Replaced one cylinder head with new one. 1300 hrs on machine. Cylinder head replaced becaise valve guide on exhaust side had moved causing push rod to bend.
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #5 ·
Thanks. I just noticed that i put in my first report that the valve where the push rod did not pop out was 0.15mm but it actually was around 1.5mm (.059"). My concern is why the gap went from around what i set at .08mm (.003") to 1.5mm (.059"). The rocker bolts were tight when i took it apart.
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #9 ·
Hi, just to update. I put the push rods back in and set the valve clearances. Checked very carefully that i was at tdc on compression stroke. As suggested, i rotated the engine 10 cycles and there was a massive valve clearance. I re-set the valve clearance and rotated the engine again and this time it was ok. I am thinking that the push rod was not seating properly into the cam followers. Probably, this is why the push rod popped out the first time. I will try mowing the lawn tomorrow.
 
1 - 5 of 5 Posts
Top