timing problem

[Michael Madriaga]

i found the timing belt broken on a 95 marathon. i replaced it and it ran fine at first. then it lost power and i found oil in the breather cover. any ideas what the problem is?

[Gearhead1956]

How long did it run fine, min, days or mo's ?

Have you checked the idler pully is still holding belt tight?

Did it loose power all at once or gradually?

Could the oil in air box have been there for some time, or do you know for a fact its new?

Will it start and run?

[Michael Madriaga]

i had it running good with the rear tires off the ground for testing. i ran it for about 10 to 15 min. to make sure it was firing good and the drive clutches worked all the way to full speed. i then drove it about a block down the road and it started to loose power. i got it back to the barn and thats when i found the oil in the carb breather.

[CP241]

Sounds like it may have slipped a tooth, any chance the tensioner came loose? Might be worth double checking the timing marks.

Do you know why the timing belt broke to begin with? Did the cam gear lock up? Have you checked valve clearances or compression? These motors are known to wear intake valves.

[Gearhead1956]

I'm with CP on this one.

need to check timing and idler.

Sounds like it may have had this condition from the get go. An engine some times may seem to run fine in a unloaded condition ( on jack stands ) but you don't know if its making power till you drive it. If timing is off just a little an engine will act this way.

There are other things, but since you just done timing belt I would start there.
Wouldn't hurt to run the valves.

From there you can address the concerns I think CP was implying that maybe the cam was locking up and that's what caused the belt to brake.