Impeller service on Honda twin 40hp

Larry H · Posted: Mon Feb 11, 2008 2:59 pm Post subject:

Jay,

Be very careful in removing those lower unit bolts! It is possible to break off the SS bolts if they don't release.

If they have not been removed in seven years they may be well stuck. In the shop, we used a propane or MAP gas torch to heat the housing around the threads to expand the aluminum housing. The heat required is hot enough to smoke the paint. Be careful if you use a MAP gas torch, they get hot enough to MELT the aluminum.

Hunkydory · Posted: Mon Feb 11, 2008 3:12 pm Post subject:

Thanks Larry---Have a gas torch and will use it. If I break one off it will be a pain. With so far to go for preventive maintance or to fix my attempt, I sometimes hesitate to long before doing needed work and those shop manuels leave a lot to be desired. Always easier the 2nd or third time. At times it seems the longer I work the bigger the job grows.

Jay

Captains Cat · Posted: Mon Feb 11, 2008 3:23 pm Post subject:

Big Mac

After finally getting the kits for impellor replacement on the Mary Ellen and the generous offer of a Honda shop manuel from Darrel of Lucky Fin I recently tackled this job.

The Mary Ellen is a 2001 with only 135 hours. I retired recently so that will change. A little background on usage. We use the boat mostly in Puget Sound with about 10% other use in the Columbia or local lakes. I always flush the engine after salt water use and the boat is on the trailer and in a shop when not in use. I have used SaltAway once last year.

When I took the lower units off I had no problems with getting the bolts out, although they were very dry. I use some anti-seize when I re-assembled. The impellors looked OK, but had some very obvious cracking starting on the back side of the set on the blades. I think it was a good idea to have changed them out. I also noticed a stronger pee when I did a run test yesterday on the trailer. The only trouble I had was getting the impellor over the woodrift key that wanted to slip of the slaft. I used a small amount of grease to hold it in place. The second lower unit went easier than the first. How do you others deal with the woodrift key?

I also changed out the Honda / Racor fuel filter water separator filters and they needed it. They were about 2 years old. Now all I need is a little break in the weather and off we go. Hope to see some of you at the SBS, Big Mac.

getzold · Posted: Sat Jan 09, 2010 8:46 am Post subject:

Anyone else have twin Honda's 40's or the like with close to our hours or more with no problems with water pump. If you had water pump problems at what moter hours did it occur.

I have a single Honda 40 (1999). After noticing a reduced stream (no idea of how many hours since last change), replaced impeller with full kit- including wear plates and all gaskets. Now the impeller seems to fail every year-last change was done by Honda service..

Any thoughts on what may be causing the high frequency of failures?

matt_unique