[DaveW]

Hello everyone!

I recently found this forum and have a question concerning the cam gear on a 425.

I replaced the plastic gear on my 1994 425 with 1077hrs as it needed the cover gasket replaced. I replaced the cam shaft , water pump , tappets. Adjusted valve clearance to .010.

I didn't change out the valve springs as I didn't think it would be a problem using original springs.

It now runs with a slight hiccup at any engine speed. Should I have replaced the springs with new ones designed for the steel gear as I believe it is a valve train issue?

Also, it ran very quiet with the plastic cam gear and now it has a tinging metallic sound coming from the cam area. I'm hoping this is normal with the metal gear.

Thanks Everyone!

 

[dieselshadow]

:wgtt:

Did you set the cam timing correctly?


Sent from my iPhone using Tapatalk.

 

[DaveW]

I aligned the dot on the crank with the mark on the cam gear. I'm sure it's timed correctly as I was able to set valve lash with the procedure from the JD service manual and I followed it correctly making sure flywheel marks lined up correctly with TDC of each piston while valves were closed.

Thanks for the help as this is really turning into a head scratcher.

Next step will be to perform a cylinder leak test, hopefully it isn't a burnt valve.

 

[dieselshadow]

Spray some WD-40 around the carb and intake manifold (use the straw and not too liberal) while the engine is running. If the engine changes how its running when you hit certain area, you found an air leak.

The new noise along with the hiccup sounds like a timing issue. That's why I asked about your cam timing. You might want to check the valve lash settings again too.

 

[DaveW]

Thanks Dieselshadow.

I will confirm lash setting and perform a leak down test also.

I will return with my findings as soon as possible.