Help with dp290a lower unit

Rob7Dawg

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Joined
Sep 29, 2010
Messages
26
I am new to boating and i purchased a 215 Imperial and i didn't notice the lower unit was cracked.its a DP290a.
I got it welded and it looks good to the naked eye but i have to do some grinding where the bearing carrier goes in because it shrank a little bit. i put a pile of money into this project so far and im running out of time before the snow flies:(.
should i keep trying to grind and fix it myself or should i get another lower unit (having a hard time finding a cheap enough one) or could i use another lower unit like a 280, dp280, im not sure if there is any difference in these lower units or if i bolt one to the outdrive and go.
Another thing, is there a way to use a homemade tool to get the vertical shaft needle bearing out and back in without buying the special tools? the welding company got small pieces of shavings in the bearing and i am going to replace it.
Thanks Rob
 

captmello

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Jun 30, 2008
Messages
3,848
Re: Help with dp290a lower unit

I'm not an expert, but I'm pretty sure a 280 lower unit would work. You would need a lower with the correct gear ratio for your engine, which you didn't identify. The new/used lower would need to be shimmed to fit your outdrive.

Welcome to Iboats, BTW. Let us know how it works out for you.:)
 

robjen1019

Petty Officer 1st Class
Joined
Apr 18, 2007
Messages
257
Re: Help with dp290a lower unit

you can replace the lower unit with a sp or dp 200 series. The casings are different, but will mount up. You can't take the gears out of dp and put in sp case.
 

Rob7Dawg

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Sep 29, 2010
Messages
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Re: Help with dp290a lower unit

i think the gear ratio is 1.95/1. where would you find the 200 lower unit at and will a sp work on a 21ft boat. i dont need a fast boat but i want to pull tubes around. if i get a 200 series will my shafts and bearing all work in it?

thanks for the info Rob and Mello:)
 

Rob7Dawg

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Sep 29, 2010
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Re: Help with dp290a lower unit

I have sent it back to the shop to get put back together and they are taking forever.
I finished grinding it down and got the gear to fit and the bearing carrier to fit back in snug.
I used a file bit and a sand paper drum for a drill to get it accurate but everything looks great.
It took me five hours all together to get it all to fit but i wont know if it will hold oil until i get it back from the shop.
My friend told me to use 5w90 oil in the outdrive, is this correct?
 

captmello

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Jun 30, 2008
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3,848
Re: Help with dp290a lower unit

80-90 wt gear oil is correct for the DP outdrives.

I hope it works out for you.:)
 

Rob7Dawg

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Sep 29, 2010
Messages
26
Re: Help with dp290a lower unit

i got the lower unit back together and it is working great:)now i ran into another problem. (AQ271).the coolant hoses were all loose and i pulled one off and there was no coolant in the line. there are 2 belts missing that run the alenator and the oil cooling pump i think. how do i get coolant back into the motor? i see the pump on the bottem but i dont know where to add any. i also noticed that when i hooked water to the outdrive using muffs, no water came out of the exhaust. what should i do or look for? where can i get a manual online for this motor? thanks for any help and getting me this far.
 

captmello

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Jun 30, 2008
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Re: Help with dp290a lower unit

If you have fresh water cooling, you should have a tank on top of the motor. Are you sure it has closed cooling?
 

Rob7Dawg

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Sep 29, 2010
Messages
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Re: Help with dp290a lower unit

i didnt see a tank on top of the motor. i can see the thermostat on top and it has 2 big and 2 med size hoses in it. i can see the pump on the front lower part of the motor. i have looked all over this site and didnt see any threads about this issue so i am stumped. its a aq271a motor. the guy i bought it off of hooked muffs to it and the water pumped out but i cant get water to pump through it. the motor started to overheat and it had white smoke coming out the exhaust so i shut it down. thats when i noticed the coolant hoses were loose and it had no coolant. i am going to tighten everything back down but should i prime the raw water pump? where do i add the coolant for the motor, i followed the coolant hoses but it started getting dark and i dont see a resivor for it. would the water cool down the motor to?
 

captmello

Captain
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Jun 30, 2008
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3,848
Re: Help with dp290a lower unit

Your engine is raw water cooled. It uses the same water in which your boating to cool the engine.

Yes, pull the cover off or the raw water pump on front of the harmonic balancer and have a look at the impeller. If you don't know when the impeller was changed last, you may as well change it. every two years on those impellers.

Let us know what you find.:)
 

Rob7Dawg

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Sep 29, 2010
Messages
26
Re: Help with dp290a lower unit

i pulled the hose off because i cant get the cover off without taking out the motor mounts and i put my finger in the port and i felt the nubs on the outer side of the impeller. i looked at one online and it feels like there all there. i used an allen wrench to turn the crank and i felt the whole way around. i ordered belts from grainger.com and i measured with a string and the belts are 42" and 34" by 1/2" wide. im going to try these two and see where that gets me. the belts were alot cheaper than going thru a marina and ordering them. im going to get antifreeze and dump in the lines if i dont get it done before the snow flies and turn the motor over so it circulates. im confident that the belts will be here next week but i never know when they will be here. i looked a little bit more at the motor and everything else looks good. no water in the oil or in the bottom of the engine compartment. i will need to get an oil line from the pump to the back of the motor. not sure what that line is called.
 

captmello

Captain
Joined
Jun 30, 2008
Messages
3,848
Re: Help with dp290a lower unit

You only need to drain your block and manifolds and water pumps to keep it from freezing and being damaged.

One piece of advice, start a new thread for each issue. You'll get better help and info.:)
 

Rob7Dawg

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Joined
Sep 29, 2010
Messages
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Re: Help with dp290a lower unit

i will just drain everything and start a new post when i get the belts and see how everything works out. thanks for all the help mello:)
 
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