merc35hp impeller replace

[tb56dog]

I have a 86 35hp merc. I replaced the impeller,pump was working great the next day it just dribbled then smoked.Pulled it back apart, impeller was froze.Did I make a rookie mistake in installing the impeller or what?I don't understand why it worked good in the beginning.I watched the video but my sound isn't working so I missed a lot of info.I thought maybe something obstucted the impeller so I did blow out the tube and lower casting and found no obstruction.Bottom plate and cup are in good shape no marring.I'm not sure what to do next.

 

[rickdb1boat]

Re: merc35hp impeller replace

Might have installed it with the vanes facing the wrong way. Good to put some liquid soap on it when you assemble it into the housing. MAkes it easier to install and lubes it for the first start. Most times the vanes will correct themselves when it starts, but best to do it right. Are you sure it was picking up a good supply of water? Don't take long to fry one running dry...

 

[gatorred]

Re: merc35hp impeller replace

i pack the impeller in vaseline or white grease to don't run motor out of water 5 sec well burn it out.

 

[tb56dog]

Re: merc35hp impeller replace

I did use dishsoap on the SECOND one used vaseline on the first.Assembly goes ok but second is doing just like first when I first start up shoots a great stream of water then slows down now nothing I shut er down the second I saw stream stop[fingers crossed]The motor is clockwise turn looking from top at flywheel vanes are bent to cup water, tip of vane leads the way .Is this correct??

 

[tb56dog]

Re: merc35hp impeller replace

P.S. I'm using muffs in the drive and their staying in place why the good start then the fizzle I'm confused

 

[AMD Rules]

Re: merc35hp impeller replace

Actually, you wrote "tip of vane leads the way"... thats backwards.<br /><br />The tips rubbing against the inside of the housing are the trailing edge of the vane. The impeller tips should point -away- from the direction they are spinning. If you rotate the drive shaft by hand,that is the natural direction for the vanes to bend.<br /><br />For example, the impeller below would rotate counter-clockwise when viewing it from the bottom side, as shown.<br /><br />

 

[tb56dog]

Re: merc35hp impeller replace

Well I guess I'll find out if I have to buy a third impeller when I tear it back apart tommorrow.Thank you everyone for the info.I'm down to about 1/2 a hour for r and r on an impeller now just needed practice.It' only money and you can't take it with you.Thanks again ,I'll let you know how it turns out.

 

[tb56dog]

Re: merc35hp impeller replace

Well tore it apart,no damage.rickdb1boat you were right all but 1 vane had corrected.double checked for obstructions.I can't understand why it fizzles out from the telltale.If nothing at telltale, does this mean water is not pumping through the motor?Could it be leaking out from the bottom?Also I have one thick washer [1/4 "]that slides over shaft on top of pump housing.Is this all there should be?

 

[Texasmark]

Re: merc35hp impeller replace

Butting in, The pump is self contained mechanically; i.e. it is bolted together (by you)so external hardware on the shaft has nothing to do with it picking up water....if that helps your curiousity with the one washer. Don't have a manual close by so I can't comment on the complete stackup.<br /><br />Not sure that you have completely solved your problem. With only 1 tip backwards I don't know why the ones installed correctly don't go ahead and carry their part of the load, and why the backwards one doesn't work too; just would have a short life.<br /><br />Have you put ear muffs on the lower unit with the garden hose at full open and tried it? If so, what was the difference in the performance of the tell tale?<br /><br />Mark

 

[rickdb1boat]

Re: merc35hp impeller replace

Are you installing the impeller key? Have to ask....<br /><br />EDIT: I'm sure you are or it would not have tried to correct itself....

 

[tb56dog]

Re: merc35hp impeller replace

I have a clymer manual but it is so general covering several models so i wasn't sure on the exploded view.I have an old 40merc broke it down same set up so I'm guessing 1 washer.yes key is in place been double checking everything before I fire er up and wake the neighbors.Attached hose to copper pipe water comes out telltate and nowhere else that I can find.well,time to get up!

 

[AMD Rules]

Re: merc35hp impeller replace

What's the serial number of your motor? I'm puzzled as well. Thinking maybe the pump assembly must have a leak somewhere preventing it from buidling pressure. Did you check the water inlet side of the pump for obstructions? Glad to hear your impeller is ok.

 

[tb56dog]

Re: merc35hp impeller replace

well not sure if maybe I dislodged something or pump cavitating while correcting itself but she spitting a great stream I duct taped the muffs in place without screen in place just to be sure.Thanks for the help really appreciate it.I do have another problem.clymer manual tells me there are 2 windows for my 35 hp but all I have is one elevated pointer for timing so now I question the rest of the info on timing also the method in the book is to be done while motor is running.Is there a way to time it while not running as i have read in forum for other models?

 

[tb56dog]

Re: merc35hp impeller replace

serial#0H 998162 it is pretty legible but 2nd letter could be A . I've yet to find this number refered to in the manual

 

[AMD Rules]

Re: merc35hp impeller replace

Serial Number: 0A998162 Model Number: 1035716<br />1986 2cyl 35hp<br /><br />Exploded views can be found at mercurypartsexpress.com using that serial number.<br /><br />'windows'? You should have an intake cover and an exhaust cover, on opposite sides.<br /><br />Glad to hear you have good water flow again.<br /><br />Not sure about the timing. I don't have a 2 cylinder manual. Might be a good investment to get a copy of the factory service manual. From what I have seen, they are way better than the generic manuals. Good luck.

 

[mercuryrepairfreak]

Re: merc35hp impeller replace

have you taken the pump apart from top to bottom? did you take out and install all of the parts in the right order and on the right side? of ten when i put a new impeller in i ofeten mix up my layers and that could lead to a low flow of water.

 

[rickdb1boat]

Re: merc35hp impeller replace

Not real sure, but I believe you can do the static method of timing by having someone crank the starter while you hold the advance full and read the timing. Others more familiar will know more. But I believe it would get you close until you can run it on the water...

 

[Yepblaze]

Re: merc35hp impeller replace

Lets assume you have a good flow on a set of "Muffs" while testing. Or the motor is submerged well into a large barrel or on the boat in the water.<br /><br />I've seen motors when run in place in a barrel or on the water get caught up in bubbles from the prop area and lose some of the water stream.<br /><br />But in your case I would suggest as the motor is running, to try blowing up the pee tube outlet with a blast of compressed air.<br /><br />It could be possible that loose debris is getting caught in the pee tube or outlet.<br /><br />If that is the case, just blast it with air when it starts plugging. After a few of those and running in fresh water the issue should go away.

 

[rickdb1boat]

Re: merc35hp impeller replace

Sounds like the water problem is cured... I would start a new topic related to the timing issue....

 

[tb56dog]

Re: merc35hp impeller replace

Thank you Rick,will do.Thanks everyone else water problem is solved.