1989 85hp force not staring after impeller replacement

[forced out]

i have a 1989 force 85hp,replaced the impeller,housing,insert,gaskets.engine ran fine before i replced it. original impeller vanes were all torn off.everything goes back together very simply but when i put the lower half of motor on it sounds like the battery is dead(engine barely turns).i did lube the insert and turned the impeller in counter clock wise and tried to torque the nuts on the housing to the specs printed on it(40-50 ft lbs on 1/4" nuts and 15lbs on #10 nut) but it seems too tight for a plastic housing and im afraid of breaking it.when the lower 1/2 of motor is removed engine turns fast and will probably start but i wont let it.gear case is full of oil(dark in color but not milky, should be ok)and prop turns fairly easy by hand.can the pump housing be too tight,causing drag on impeller?i got the impeller off of amazon.gaskets are right and impeller fits shaft and key way but is it possible the vanes are too long(possibly wrong size)?i have had this thing apart 10 times and cant figure it out.I am starting the motor with it submerged in a trash can with water level above the pump.ready to set fire to this thing and bury the remains.

 

[pnwboat]

Re: 1989 85hp force not staring after impeller replacement

Sure sounds like it's the wrong impeller. I've had some problems in the past in getting the correct one. Sounds like the one you have is too tall. Length of the fins doesn't have much impact as they will just bend around. If the impeller is too tall, which is what I've run into at times, it'll bind up real tight. When you insert the impeller into the pump housing, it should not stick out past the bottom of the housing. Another problem that I've seen is the slot or cut into the inside of the hole in impeller for the keyway on the drive shaft is too wide. A lot of slop. You can check by sliding the impeller down on the shaft by itself. It should fit snug on the keyway, no slop.

 

[stubtail]

Re: 1989 85hp force not staring after impeller replacement

40-50 foot-pounds is way too much for 1/4-20 or 1/4-28 nuts or bolts. You mention that that is the torque "specs printed on it" - read again - it is more likely inch-pounds. 70-95 in.lb. is a more reasonable torque value than 480-600!

 

[Jiggz]

Re: 1989 85hp force not staring after impeller replacement

I'm surprised you didn't snap off the 1/4-20 bolts with 50 FT# of torque. And yes the standard torque is 70 inch#. I say remove the lower unit again and with the gear disengaged you should be able to easily turn the drive shaft by hand with little effort. You can engage it also but will need two hands to turn it. but the bottom line is with everything properly torqued you can still turn the drive shaft by hands.

 

[forced out]

Re: 1989 85hp force not staring after impeller replacement

thank you all.i am going out to tear this thing apart again.guess im too used to workin on cars(this is my first boat-2 months of work and havent been near the water yet)i should have realized torque would be in inches,dont worry i stopped before i got it that tight cause i knew it would break.i do know that the impeller does stick out of the metal cup a little bit so i guess i will have to buy another 1 from the local shop. it sucks though because everything takes 4 days to get.this is probably a stupid question but since i have to buy another impeller anyway can i trim the end of it flush with the cup and try turnin it over to see if it will start?i appreciate all the info.The waves call but my boat just laughs!!!