‘01 Sportster LE Sudden Loss of Thrust

[wtjonny]

I know this question is beat to death but I need help Boat was running great then loss most propulsion. I’m trying to figure out where the issue is coming from. I have damage in the Jet Pump Tunnel. Also on wear ring but the clearance seems to be minimal. Carbon Seal looks great (water in hull is from me not a leak) Could someone see what they think from these pictures? It wasn’t a gradual loss of thrust it happened within 20 seconds

 

[mikidymac]

That isn't an OEM wear ring and the sealing edge looks pretty beat up.

Where is the rubber sealing ring for the pump to hull?

 

[whitewheels]

Motor running as it should?
Did you regain any thrust after?

First thought was that the carbon seal lost it....sudden loss of thrust...but it looks fine

 

[wtjonny]

Thanks for the reply. I guess I was more focused on the clearance rather than anything else. So the edge might not be sealing effectively and causing air in pump perhaps? And here is the ring. Couple imperfections but otherwise decent shape.

 

[wtjonny]

Motor running as it should?
Did you regain any thrust after?

First thought was that the carbon seal lost it....sudden loss of thrust...but it looks fine

Yes motor starts instantly and revs high

 

[wtjonny]

I have a new wear ring and pump housing on the way. But it seems strange to me that this happened out of nowhere after 2 or 3 months of decent performance. I say decent because it had some cavitation coming out of spins and such

 

[mikidymac]

I would also check the splines on the PTO, both ends of the driveshaft and impeller. Also the carbon seal sealing surface while the pump is out.

 

[whitewheels]

Can you have hit something ,sucked through the pump? Was it no thrust at all after

 

[wtjonny]

I thought I may have sucked something but nothing was in there when I pulled the pump. I’ve had it in the water twice since then trying to find the issue.

the splines on the pump side look good I think but I suppose it could be stripped in the engine? Damn

 

[whitewheels]

Yeah pull the driveshaft and check and get back to us [emoji1783]... then you also see how the carbon ring looks

 

[wtjonny]

Sweet, any good write ups on pulling the driveshaft?

 

[mikidymac]

Pump needs to go back in to pull the carbon seal. Driveshaft won’t come out without removing stainless hat from carbon seal.

 

[wtjonny]

Wellllllll. I pulled the shaft. Does seems to be stripped a bit.. not bald but not perfect either. Also pulled the carbon seal out for inspection. What do you guys think? I tried to look up into the PTO but so much oil and stuff it’s hard to tell what those teeth look like. I really appreciate the help everybody!!

 

[whitewheels]

yes not bald but definitly not bad enogh. I would get a new carbon seal just to be sure.
Did you have any thrust at all after you suddenly lost it?

 

[wtjonny]

I have some thrust. Like idle speed. I can get around if I HAD to. But it doesn’t have much else after that.

 

[mikidymac]

I don't think we are seeing the same thing here. That dirveshaft is shot. The splines are worn so thin they are almost gone on the high points. My guess is the PTO is just as bad inside.

 

[wtjonny]

Yeah upon further inspection the edge of every spline is worn down. I don’t even know where to begin on repairing the PTO. I agree with you it’s probably screwed up as well. I guess this shaft could be my problem then?

 

[mikidymac]

Yes, it could be your issue.

You will have to replace the PTO and driveshaft.

 

[wtjonny]

Thanks for the help. Could you steer me in the right direction where to go from here. Will I need to pull the motor?

 

[mikidymac]

No the motor doesn't have to come out.

I get the engine to TDC on the rear cylinder with a straw down the sparkplug hole then go clockwise from that until the straw drops about 3/4" then feed rope down the sparkplug hole to lock the piston. When you turn the PTO counterclockwise it should jam the rope between the piston and cylinder head. Then use a chain wrench to unscrew the PTO.

 

[wtjonny]

Cool I’ll get to work thanks

 

[whitewheels]

I don't think we are seeing the same thing here. That dirveshaft is shot. The splines are worn so thin they are almost gone on the high points. My guess is the PTO is just as bad inside.

Can this happend if you suck in some debris or what can cause this? ...no grease?

 

[wtjonny]

Can this happend if you suck in some debris or what can cause this? ...no grease?

i had a lot of play in my impeller shaft and I think it was causing the drive shaft splines to not sit very well together. When I pulled the impeller shaft a million pieces of bearing poured out. Also didn’t have the rubber stopper on the engine side of the drive shaft. So I think it was moving in and out too far but I don’t know

 

[wtjonny]

No the motor doesn't have to come out.

I get the engine to TDC on the rear cylinder with a straw down the sparkplug hole then go clockwise from that until the straw drops about 3/4" then feed rope down the sparkplug hole to lock the piston. When you turn the PTO counterclockwise it should jam the rope between the piston and cylinder head. Then use a chain wrench to unscrew the PTO.

What exactly do I do with these bolts at the end of my screw driver? Does it pull off as one unit or do I need to remove the bolts first

 

[mikidymac]

I didn't realize you had a 951 engine, You got lucky and the PTO with the splines just unbolts. No need to lock the crankshaft or mess with the engine. Just unbolt the part with the splines and you are good.