Impeller change help needed, 175 hp Optimax
Posted: Tue Apr 16, 2013 5:13 am
So last season I started getting a engine buzzer when idling along real slow like for long periods of time, an uptick in speed usually cleared it up right away so I figured it was time for a new impeller. It's a 2008 with just over 100 hours on it, was a test engine when I bought it in 2010, had never been titled but had about 50 hours on it.
I'm mechanically inclined and have pulled lower units before, plus I watched a few youtubes so I figured what the heck, I can handle this. Pick up the impeller kit at the local boat shop, back the boat in the shop and start disassembly. Everything comes apart pretty easily (once I find all of the bolts) and out drops the lower unit. Get the lower unit on the bench, get the impeller swapped out and everything buttoned back up lickety split. Everything looks in great shape, the impeller has a permanant curve to the splines but isn't chunking or anything and no apparant wear on anything else.
Great, I'm on a roll...another 15 minutes and this job wil be done...wrong...
Getting everything lined back up for reinstall has proved to be a challenge. First, when I pulled the unit down, the copper pipe that feeds the water up to the block came with it, is that normal? On all of the videos I watched, that pipe seems to have stayed in the block. Also, are there bushings or seals that are supposed to seal that copper tube to the block? And what about to the impeller housing?
I took the pipe loose from the white plastic tube on the housing and tried to get it to stay up in the block and it just falls out. Doesn't seem like a very tight connection for a water cooling system.
Since giving up and coming in last night, I've learned a few other tricks I wish I knew beforehand, like putting the shifter in forward before disassembly (I left it in neutral). Also the turning of the flywheel to line up the splines...I'll try that next go around.
One more question, there is a small plastic tube hooked to a fitting at the very front of the top of the LU, is this a speedometer pitot? I think the other end of that tube is hanging out the front of my engine not hooked to anything (boat speedo pickup on end of toon). If that is the case, do I need to worry about getting that plastic tube back into the fitting while putting the LU back up into place? I will verify where the other end of that tube goes beforehand but I'm 95% sure that's what this is...again, something I wish I would have know beforehand.
So my main questions are, what do I need to make sure is on the white plastic tube and copper pipe as far as seals and should that copper pipe be up into the block or on the LU during install?
I and the wife were trying to reinstall the LU with the trim up and the engine at an angle last night. I think tonight I'll get the shafts in place and lower the engine straight down and use a floor jack to slowly raise the LU into place. This seems like it will be easier to line everything up and not so hard on my arms.
Thanks for any help you can provide...need to get this done and get the boat on the lift so spring can officially start (if it ever quits freezing around these parts).
Lance
I'm mechanically inclined and have pulled lower units before, plus I watched a few youtubes so I figured what the heck, I can handle this. Pick up the impeller kit at the local boat shop, back the boat in the shop and start disassembly. Everything comes apart pretty easily (once I find all of the bolts) and out drops the lower unit. Get the lower unit on the bench, get the impeller swapped out and everything buttoned back up lickety split. Everything looks in great shape, the impeller has a permanant curve to the splines but isn't chunking or anything and no apparant wear on anything else.
Great, I'm on a roll...another 15 minutes and this job wil be done...wrong...
Getting everything lined back up for reinstall has proved to be a challenge. First, when I pulled the unit down, the copper pipe that feeds the water up to the block came with it, is that normal? On all of the videos I watched, that pipe seems to have stayed in the block. Also, are there bushings or seals that are supposed to seal that copper tube to the block? And what about to the impeller housing?
I took the pipe loose from the white plastic tube on the housing and tried to get it to stay up in the block and it just falls out. Doesn't seem like a very tight connection for a water cooling system.
Since giving up and coming in last night, I've learned a few other tricks I wish I knew beforehand, like putting the shifter in forward before disassembly (I left it in neutral). Also the turning of the flywheel to line up the splines...I'll try that next go around.
One more question, there is a small plastic tube hooked to a fitting at the very front of the top of the LU, is this a speedometer pitot? I think the other end of that tube is hanging out the front of my engine not hooked to anything (boat speedo pickup on end of toon). If that is the case, do I need to worry about getting that plastic tube back into the fitting while putting the LU back up into place? I will verify where the other end of that tube goes beforehand but I'm 95% sure that's what this is...again, something I wish I would have know beforehand.
So my main questions are, what do I need to make sure is on the white plastic tube and copper pipe as far as seals and should that copper pipe be up into the block or on the LU during install?
I and the wife were trying to reinstall the LU with the trim up and the engine at an angle last night. I think tonight I'll get the shafts in place and lower the engine straight down and use a floor jack to slowly raise the LU into place. This seems like it will be easier to line everything up and not so hard on my arms.
Thanks for any help you can provide...need to get this done and get the boat on the lift so spring can officially start (if it ever quits freezing around these parts).
Lance
Once I corrected that, it shifted into forward and reverse just like it was supposed to. 
