omc lower unit will not drop down

[dormond]

I purchased a 21ft mitch craft 6 months ago used<br />it has twin 1993 omc 1.6ltr 140hp engines on it. both motors run good last time went out one engine overheating buzzer came on very little water coming out of pee tube. tried to take lower unit off and it will not drop down but about 1/2 inch and no more. have taken off 4 bolts on outside of motor, trim tab and bolt underneath, bolt by anode, and shift lever bolt under carbuetor. still will not come down using wedges. model# 16AMRJAS SERIAL# 1518200 <br />any help appreciated.

 

[Laddies]

Re: omc lower unit will not drop down

The water pump is under the rear cover not in the lower unit if you didn't screw up a seal or o-ring put it back up and ck under the cover

 

[tommays]

Re: omc lower unit will not drop down

kinda sounds like and outboard but i may well be wrong<br /><br />tommays

 

[dormond]

Re: omc lower unit will not drop down

yes this is an outboard engine. i need to drop the lower unit in order to install new water impeller. but it will not drop. can not find manual in my area to look at the motor schematics.

 

[DHPMARINE]

Re: omc lower unit will not drop down

dormond,I think you have OMC SeaDrives.<br /><br />I didn't realize they continued into 1993.<br /><br />If it is 1993,you should be removing a hitch pin from the shaft that moves the shift rod under the carb.<br /><br />If it is older and I think it is... did you remove the wrong bolt under the carb?<br /><br />The bolt to remove is situated port to starboard or visversa and is accessable from the port or starboard side of the engine.<br /><br />If you removed a bolt that is accessable from the front of the engine,and runs fore to aft,it's not the right bolt.<br /><br />DHP

 

[Laddies]

Re: omc lower unit will not drop down

DHPMARINE you are sure right I just looked at the 140hp and assumed they were Cobras not SeaDrives on this site I goofed---Bob

 

[dormond]

Re: omc lower unit will not drop down

yes these are seadrives. what i removed was a bolt that ran from port to starboard about 1 1/2 inches long with threads about half way this ran through the hole on top of shift shaft. even with this diconnected and all bolts out lower unit will not drop down. i know the boat is a 1993 model and the previous owner told me the motors were also 1993 but i cant find a manual for these motors.

 

[DHPMARINE]

Re: omc lower unit will not drop down

dormond,<br /><br />Sounds like you have all the main bolts out.(the lower unit drops 1/2 inch.Otherwise it would still be snug to the upper exhaust housing.)<br /><br />1 1/2 bolt you removed is the correct shift one.<br /><br />Time to pry firmly down,with 2 screwdrivers one on each side of the case.<br /><br />DHP

 

[dormond]

Re: omc lower unit will not drop down

have tried screwdrivers, wedges, crowbar and a 5-lb slide hammer. any other suggestions?

 

[rodbolt]

Re: omc lower unit will not drop down

have the engines had a 5" spacer added? there were some kits to lengthen a 20" motor to a 25". the kit uses a splined stub shaft that will stick to the shaft. or the drive shaft is stuck in the crank spines.

 

[dormond]

Re: omc lower unit will not drop down

not sure if spacer has been added. if the shaft is stuck in the crank spines what is the best way to get these apart? motors run good but if i cant change the water impellers then eventually they will overheat and blow.

 

[rodbolt]

Re: omc lower unit will not drop down

hello<br /> the last one I had that was stuck I had to cut the drive shaft just below the crank and replace the shaft and the crank. we tried for 7 hours to remove the splines from the crank. we even drilled and tapped the shaft to use a pusher bolot. then we welded a slide hammer to it. never did come out. was on a pair of 225 loopers from 1995. goes back to maint. if done everyother year they never stick. sometimes heat on the shaft at the crank will help. sometimes they never come apart.<br /> sorry