timming belt keeps walking on me

[imported_raymond2688]

threw the timing belt last weekend. it did not come all the way off so no internal damage occured. I put the new on back on just as the volvo mannual told me and as I am turning the engine over a couple of times with a ratchet the belt is slowly moving off the gears. I did not put the pulley back on for the water pump but it should stay in line without that I would think.
I checked the tensioner and there is very little play in it but there is some. is this what is causing my problem????

the boat is a 1989 bayliner trophy with a 230 B volvo engine

Thanks

 

[Don S]

Re: timming belt keeps walking on me

Yes, replace the tensionser.

 

[imported_raymond2688]

Re: timming belt keeps walking on me

thanks don I greatly appriciat the input