cant find vin #'s on my 85 horse Force and no spark to clyinder

[newguy84]

Hello guys, i just bought a 1988 17 ft Sea Sprite with a 85 horse Force OB on it made by U.S Marine. I cant seem to find the vin #'s on it to determine the year of the motor. Maybe it is original and came with the boat and i could get a part number off the flywheel and have it ran at my local marine store? Also i took it out for the first time the other day and it fired right up with teh turn off the key. When i went to give it throttle it wanted to get up on a plane but acted like it didnt have the power. I took off the wires and pulled the plugs. The middle and bottom plug seemed to be firing but the top one was clean and a lil gas soaked. Is the reason the motors not getting spark to that plug and clyinder because of a bad wire and coil?and is this the reason my boat isnt wanting to move like it should?

Thanks for everyone and anyones help and sorry for the newb questions

 

[MWBROWN]

Re: cant find vin #'s on my 85 horse Force and no spark to clyinder

Welcome to IBOATS.

My serial number is on a plate that is under the cowl, near the front right side (starboard) , just to the right side of the carbs. Mine is an 84.

Others will show up to answer your othe issue, as they could be many tough, and or very simple cures. When my #2 went out it was the CDI module. One of the two modules fires #1 and #2 and the other fires #3. I think you can swap them to prove the problem is the CDI module. If it is, I think #3 will not fire. There are a couple other things, like no compression, bad plug, bad wire, bad coil, stator or trigger that could cause the same problem. Not sure how to test the stator or the trigger. Bad wire and coil are obvious and easy to swap.

Good luck,

Mike

 

[newguy84]

Re: cant find vin #'s on my 85 horse Force and no spark to clyinder

Hey thanks MWBROWN glad to be a part of this boating community. This forum has been very useful to me ,as i am new to the boating scene.
The vin # i will check for thanks for the tip,although i didnt see a plate on the entire motor it might be stamped. Today i was told it was prolly the CDI module by a guy who works at a West Marine store ,so i went ahead and got one ordered,it should be here in like a day or two he said. Alright, once again thanks for replying MWBROWN and i will let u know how things go in the days to come. Safe boating to all!


Justin