AQ171c Timing Belt change

[AQ171C270SP]

I was cruising at about 3200 RPMS when the motor just stopped. Not knowing what happened my first reaction was to turn the key and try to re-start it.Well when I cranked it over the motor spun way to easy. I stopped cranking and lifted off the engine house cover.I starting looking for water leaking from the head or anywhere for that matter,I inspected the oil it looked fine.Then there they were ,cogs to the timing belt laying in the bildge.I was about to get up and anounce my findings to the other people on the boat but before I got the words out one of the guys began to crank it over again.My question is the AQ171C twin cam motor an interference motor,I believe if it is the damage was already done when I attempted to restart it. Okay 2nd question,where are the line up marks located? I would like to put a new belt on and be on the water for the weekend.Or if I have to take the head off and at a minimum put new valves in it and at least get to use it once or twice before it is time to take it out of the water.If anyone has any shortcuts or other pointers please answer asap. Don, Don whats your input. Thanks to all for all the good info on here

 

[johnscram]

Re: AQ171c Timing Belt change

I have the instructions from my seloc repair manual that i will scan in soon, that will get you going! As far as the interference is concerned if the motor cranked over seemingly easier i would say your ok, seeing that you didnt hear any nasty noises.

 

[johnscram]

Re: AQ171c Timing Belt change

Uhh ohh i just looked in my manual and it says the dual overheads are interference engines, it says if the timing belt brakes you should definitely pull the head to check for damage.

 

[TheKatsass]

Re: AQ171c Timing Belt change

As the last post stated, your motor is an interference motor, the head should be removed. Pick yourself up one of the Seloc manuals and start stripping it down. Just to note:these engines were very similar to the automotive versions except for the valves, cams, headgaskets, intake, carb and the marine equipment. But seals will be the same aswell as belts just to save a buck or two. We just did the SOHC head on our AQ131A and it totalled out around $1100 CAN. with us doing the removal and install. But just the guides and a good cleaning was done. Yours will be considerably more if you have to replace the valves as there are 16. Ill give you an approximate value for each, I know the SOHC valves were $60 a piece.