1986 Merc 75 ELPTO dies when going into gear

[rwtimm]

I have a 86' Merc 75HP that runs fine when on the water wings, goes into gear and runs. When in water it idles fine, but dies when put into gear . I have had a new switch box & trigger put on. Stator is good. Fire to all 4 cyl's. Ideas?????

 

[Texasmark]

Idling too low. Should be around 700 rpm in the water in F gear...like the way you would be heading out from the launch to the no wake markers. Fast enough to keep it running but not so fast as to cause unnecessary "clunking" and gearbox wear and tear. If that doesn't do it open your low speed idle screws 1/8 of a turn at a time till it will stay running and take throttle when you punch out in the hole shot.

 

[Faztbullet]

whats the compression???

 

[rwtimm]

compression is 140 in all 4 cyl. I thought the motor was idling high. When I dropped it into gear it clunked a little. Could this be carbs as the motor sat for a while and they have not been rebuilt in several years?

 

[Texasmark]

compression is 140 in all 4 cyl. I thought the motor was idling high. When I dropped it into gear it clunked a little. Could this be carbs as the motor sat for a while and they have not been rebuilt in several years?

140 is great. Manual says below 120 start to think about a problem. If you clinked, as said, idle too fast. Go to the archives and look up Decarb. Do it and then keep some SF in your gas. You'd be surprised how many problems that can of dynamite will cure.