Engines won't turn over after pump rebuild

[ohtenwillys]

Help! Rebuilt both pumps completely and they free spin before reinstalling in boat. Went to start and starters couldn't turn engines over. Thought it was the batteries so I pulled them and had them charged. Put them back in and still same issue. Is it possible to overtighten the pump housing nuts on the studs enough to cause the engines to not turn?

 

[Coastiejoe]

If it isn't square and or the pinch washer is pinched, it will lock them up.

Lube the wear ring up with some grease as this will help and less damage will happen to the ring when it does start for the first time.

 

[ohtenwillys]

Idk how to delete a post

 

[ohtenwillys]

If it isn't square and or the pinch washer is pinched, it will lock them up.

What's a pinch washer?

 

[Coastiejoe]

I've not had a 2-stroke pump apart in my hands, so I can only tell you what I have read. There is a washer that most of the 2-stroke guys refer to a pinch washer. I'm not where I can open a parts list right now.

 

[ohtenwillys]

Hmm it's probably the thrust washer between the flange on the shaft and the roller thrust bearing. I'm gonna check to make sure I didn't just tighten the pump housing down too much and seize up the bearings.

 

[Sportster-2001-951C-Stock]

Yes, I think they mean the thrust washer can be off center (somehow) as the impeller is torqued onto the pump shaft, then thrust bearing will be pinched. But it doesn't seem that's what happened in this case.

Fill us in on more detail about what was done exactly and your observations, were your impellers, bearings and shaft also replaced? Was there a washer placed behind the impeller?

ie: I'm wondering if your impeller is being shoved into the pump bearing hub, causing this bind. Might be the wrong impeller or shaft?

 

[ohtenwillys]

So I loosened all the nuts on the pump housing studs like half a turn and both engines started and ran fine. Stupid torque wrench.... So idk if I'll need new neoprene seals since I might have over crushed them. How tight do y'all tighten the 4 nuts?

 

[mike_tyler]

Now that you mention this I will have to check mine as I just did my pump on my Challenger.

 

[ohtenwillys]

Yeah my torque wrench didn't click at 15 ftlbs like it was supposed to.

 

[Sportster-2001-951C-Stock]

So I loosened all the nuts on the pump housing studs like half a turn and both engines started and ran fine. Stupid torque wrench.... So idk if I'll need new neoprene seals since I might have over crushed them. How tight do y'all tighten the 4 nuts?

It just hit me, probably when you torqued it down the wear ring was crushed a little and caused it to rub on the impeller, if yes that's okay. You might find now, that doesn't happen or you can final torque it while the engine is idling.

I doubt you'll have any issues with the neoprene seal as long as it's in correctly, they're pretty tough and don't have much memory till they get old.

23~25ft-lb with blue lock-tight should hold it good, no more than that.

 

[Cablebandit]

man i'd still want to pull pumps and make sure that thrust washer didnt slide into that groove on the impeller shaft. it is EASY to do...I did it in one of my 2 pumps.

 

[mike_tyler]

I know there is thrust movement in the pump and most engines require some degree of thrust end play to operate. Once pump is installed should there be some minimal amount of thrust movement along the driveline?

 

[ohtenwillys]

It just hit me, probably when you torqued it down the wear ring was crushed a little and caused it to rub on the impeller, if yes that's okay. You might find now, that doesn't happen or you can final torque it while the engine is idling.

I doubt you'll have any issues with the neoprene seal as long as it's in correctly, they're pretty tough and don't have much memory till they get old.

23~25ft-lb with blue lock-tight should hold it good, no more than that.

I did spray some WD-40 in the pump so i'm sure that helped.

 

[Cablebandit]

with the rubber bumpers installed in both ends of driveshaft, im not sure how much play there should be. As far as thrust washer goes, my pump would spin fin until i installed cone and then it got a lot tighter which was my clue to the thrust washer being un
seated

 

[Sportster-2001-951C-Stock]

with the rubber bumpers installed in both ends of driveshaft, im not sure how much play there should be. As far as thrust washer goes, my pump would spin fin until i installed cone and then it got a lot tighter which was my clue to the thrust washer being un
seated

If I understand correctly, we aren't experiencing an end play issue. This is the common impeller clearance with the new wear ring friction which is common until the impeller "carves" the wear ring to a final clearance fit.

As the pump is torqued up to the pump support, the wear ring is slightly crushed against the support thus the inner diameter is slightly decreased.

 

[Coastiejoe]

You could tighten it up as you should. Then loosen the bolts the same amount each, say 1 turn for example. Then crank the engine to wear the ring a bit. Tighten the pump down and see what happens...

 

[SeaDoobious]

You could tighten it up as you should. Then loosen the bolts the same amount each, say 1 turn for example. Then crank the engine to wear the ring a bit. Tighten the pump down and see what happens...

Tried this with seemingly the same issue, not to say it won't work for the OP. What I experienced was the hub of the impeller shaving the plastic hub of the stator. Almost as if zero clearance. I'm stumped.

 

[Sportster-2001-951C-Stock]

Tried this with seemingly the same issue, not to say it won't work for the OP. What I experienced was the hub of the impeller shaving the plastic hub of the stator. Almost as if zero clearance. I'm stumped.

The impeller hub shouldn't rib on the pump hub.

Have you changed your shaft and/or impeller? Might be one of these isn't correct OR, the thrust washer and bearing are out of position b/c it's easy to get them misaligned during assembly.

 

[SeaDoobious]

I agree, curious whether shim is the solution or if Im crazy. No pinching, no wear ring warp, fresh pump. Mic'd the hub on both and height of impeller from tip to hub is 1.2mm taller than stock impeller. Concorde 15/20. Anti rattle cone is new, blue plunger style. Again mine is for a 951 155mm. I don't want to hijack nthe OPs thread, just curious if it falls into the same issue he had.

 

[Sportster-2001-951C-Stock]

with the rubber bumpers installed in both ends of driveshaft, im not sure how much play there should be.

I'd say there's at least 1/4" in mine b/c when I pump a little grease in the PTO grease fitting the drive shaft moves backward about 1/4" as the grease enters the spline area in the PTO.

If there's an old rubber bumper remaining inside the PTO or impeller, that might cause an issue as well.

 

[Sportster-2001-951C-Stock]

I agree, curious whether shim is the solution or if Im crazy. No pinching, no wear ring warp, fresh pump. Mic'd the hub on both and height of impeller from tip to hub is 1.2mm taller than stock impeller. Concorde 15/20. Anti rattle cone is new, blue plunger style. Again mine is for a 951 155mm. I don't want to hijack nthe OPs thread, just curious if it falls into the same issue he had.

The collar(shoulder) on the threaded end of the impeller shaft must be far enough outside the hub so once the impeller is threaded on and bottoms on that collar there's enough clearance to avoid having the impeller rub on the hub.

Also there are at least two pumps with different diameter hubs and I think you can't swap impellers the impeller is specific due to diameter.

Could be you're missing a shim washer on the threaded end of the impeller shaft before installing the impeller, you might even find that shim inside the old impeller.

 

[SeaDoobious]

Tried that route this morning. I'm curious if there is an abnormal depth (the need for a prop to prop shaft shim as you described) imprisoned explained it's a possibility the "new" impeller is an older revision (currently 3 revisions of this impeller from Solas). Might be time to head to the machine shop or send it to impros. Checked old prop and parts bin, no prop washer or shim, I was hoping. The hub is correct from impeller to pump, I remembered the bronze and some plastic pumps have smaller hubs; in this case unfortunately it's the right one.

 

[Sportster-2001-951C-Stock]

I'm sure someone else ran into this and eventually did find a shim/crush washer inside their original 155mm pump impeller so have another look to be sure. It's been a while, I'll see if I can locate the thread.

Otherwise you'll need to contact the impeller vender. I have a vauge recollection but don't recall the detail of which one had this and I'm not sure what it looks like exactly b/c it's not shown on the exploded parts drawing I'm looking at but the detail is important b/c if your impeller unthreads due to having the wrong parts that can shove the impeller into the drive shaft and shove the shaft into the PTO and place the thrust force directly onto the crank shaft and damage the engine bearings so it's worth getting correct and asking questions till you get to the bottom of it.

Have a look at this thread, it's not the same pump as yours but the issue is kind of similar so you might be interested in reading it.

http://www.seadooforum.com/showthread.php?78700-How-to-remove-sleeve-from-impeller-shaft-271000291