First time on the water. Runs great but barely moves on acceleration.

[bobbobobbo]

98 Sportster 1800, twin 717s. Great first run all things considered. Dual battery setup works great.

The issue I found is some significant lack of "hooking up" upon acceleration. I don't think this is normal... When I take it from idle, the engines rev up and I basically go nowhere. I can hear them like "slip" and just wind out. If I very slowly ease into the throttle, I'll eventually begin to gain speed and plane. I cannot just mash the throttle and take off, as I was expecting to be able to do

If I have a bunch of people on board, it's even worse, and the distribution of weight also really affects if I'll be able to gain speed or not. At speed, everything seemed fine. I hit 40mph into the wind with me and one other passenger. Everything sounds good and it runs smooth.

From what I've read, it's either the wear ring or the carbon seal. I know how to change the wear ring and pump oil, yet never touched a carbon seal. That's if it's either of those are causing the issue. Thoughts anyone?

 

[Dr Honda]

Unless there is major damage in the pump... you have a HUGE air leak... and that NORMALLY comes from the carbon seal.

Make sure the clips are in place, and you may even want to push the stainless ring forward, and see if there is a second groove on your driveshaft, to make the seal tighter.

 

[Albysure]

Try what dr Honda said....on your model you have 3 groves for your c clip...just push back your bellow and your floating ring and pop off the c clip and reinstall it on the next grove.....if its cavatating that bad because of the carbon seal sucking air it should be leaking water when sitting in water...

 

[bobbobobbo]

Thanks! Will do that first thing in the morning. I'll grab a bunch of pics as well and update this thread.

It may not be as terrible as I made it sound, but it's definitely there. From what I'm reading it's likely those seals, so we'll see.

 

[Dr Honda]

That is the nice thing about the carbon seal. it can be damaged to the point of ALMOST failing, and not let your boat sink. But... when you suck air past them... the cavitation can be so bad that you can't get past 3 or 4 MPH.


Here's a pic to help, if you haven't played with the carbon seal yet.

 

[bobbobobbo]

Took some quick pics. Any thoughts? It looks a bit different from that picture above.. I tried to slide the ring towards the back of the boat, yet it's going to take a bit of force first.

Here's an album. First engine, cover, then second engine: http://imgur.com/a/AMxpa

I'm not sure if it's on the 2nd or 3rd groove and which way to go.

 

[Dr Honda]

Looks like yours is on the second groove. AND... there could be a rip in the boot. Personally... I would just pull it apart to get a good look at the parts.

 

[Albysure]

Yea it's on the second one from what I see...plus if you look at your first picture the driveshaft is way out of alignment...you can see it pushing the carbon seal..

 

[Guest_User]

Ditto to what Doc says!
are those OEM clamps? they look wider for some reason. That bellows looks compressed a lot as well. I`d start of with all new and align the engine... you need 8mm (5/16) compressed length on the bellows.
read the specs from the shop service manual...

 

[bobbobobbo]

Alright, will inspect further tomorrow. Just didn't have time today, wanted to snap quick pics before heading out the door.

The carbon ring moves side to side (perpendicular to the shaft) about a half inch. I moved it some, which shows in the first pic. That normal?

For now without pulling the shaft I'm going to take out the c clip, unclamp and extend the bellow, take a look at things, etc. Try and get a good look at the face of the carbon seal.
It's already quite tight... not sure if the second groove is stock. I can't imagine it needing more pressure, yet I can slide it to that third groove I suppose.

Thanks so much as always guys.

 

[howie099]

Make sure the engine isn't moving on the that pic with the seal that is not alligned. The engine might be shifting sucking air.

 

[bobbobobbo]

Make sure the engine isn't moving on the that pic with the seal that is not alligned. The engine might be shifting sucking air.

The engine feels solid, it feels like the actual ring itself can be pushed side to side on the shaft, is that not normal to have some play like that? Is that what would cause the significant cavitation maybe? The side to side action... because it feels quite tight against the stainless ring (though perhaps it's not that tight, if im able to readily push the ring side to side)

 

[Dr Honda]

Yes... the movement in the seal is normal. It's a floating seal. The ID of the seal is bigger than the driveshaft. But... if it's been running off center (they normally do) and if that the factory seal... it's just time to change it.

 

[bobbobobbo]

Yes... the movement in the seal is normal. It's a floating seal. The ID of the seal is bigger than the driveshaft. But... if it's been running off center (they normally do) and if that the factory seal... it's just time to change it.

Ah got it. For the amount of cavitation I was getting I was hoping to open it up and find something major.. for now I suppose I'll slide it to another groove just to see. With plans to change everything soon anyway.

To make the seal tighter, am I sliding the clip to the next groove towards the rear of the boat or the front? I'm reading conflicting thread responses.

 

[Dr Honda]

OK... IF YOU ARE GOING TO ORDER PARTS, AND FIX IT PROPERLY.....


Here's some tricks. (but they are just a band-aid)


1) Try to push it forward, and see if there is a 3rd clip spot. I know it's not easy to move, especially if it's never been serviced. BUT... put a block of wood behind the PTO, and use a pry bar. (I use a tire spoon for a motorcycle) It will push it forward.

If there isn't a 3rd spot....


2) Put a couple big fat zip-ties in the valley of the boot. That will help hold it straight, and it will keep the vac of the jet pump from sucking it open.


3) put a big wipe of waterproof grease on the face of the carbon seal. Pull the seal away from the stainless ring, and put some sticky synthetic, waterproof grease. This will help seal it up... but it will soon soften, and destroy the carbon ring. SO... for the other guys reading this... grease is a last ditch try !!!!!!



If there isn't physical damage to the seal... #2 will normally make things good enough to go out for a ride. Here's a pic, so you can see where to put the Zip-Ties. And yes... you can put it on both valley's to make it even stiffer.

 

[bobbobobbo]

Thanks so much for the response.

Absolutely new parts. Along with a wear ring job. The issue is I'd like to take it out for the 4th. By the time parts come and I have time to install, it's going to be cutting it far too close.

I've read through all your old threads (very helpful). I'm not looking to do the grease trick quite yet, so I shall first see if there is another notch. I was just worried about it being too tight, since yes it is quite difficult to move, and already on the second groove (is that stock?).

Anyway to confirm, I'm moving it towards the back of the boat, thus applying more pressure on the seal. Correct

 

[Dr Honda]

Thanks so much for the response.

...........

Anyway to confirm, I'm moving it towards the back of the boat, thus applying more pressure on the seal. Correct

Yes... toward the transom.


BUT.... if you have good zip ties handy... try #2 first. It's less effort, and it stabilizes the boot.

 

[bobbobobbo]

Yes... toward the transom.


BUT.... if you have good zip ties handy... try #2 first. It's less effort, and it stabilizes the boot.

Will do. Thank you so much as always Doc

 

[bmwbirdman]

Have you checked the wear ring? This sounds just like a worn out wear ring. If the space between the impeller and the wear ring is the issue it is very easy fix.