2006 Sportster DI Air Compressor Overhaul

[despower]

Hey folks,

I have low air pressure in my 2006 Sportster DI. I believe the low pressure is coming from a leak at the compressor head - either at the cover or the compressor body. There is a gasket between the cover and the body so that's easy to replace. There's also an o-ring at the bottom end of the compressor body, which is also easy to replace. However, air compressor overhaul kits include the compressor sleeve and piston, which isn't so obvious to replace. I have the shop manual for my boat, but there's nowhere in the manual that talks about changing the air compressor piston or sleeve. Does anyone have any guidance on how this is done?

Des

 

[despower]

I found this thread in the two stroke PWC forum - its the same engine and compressor as my sport boat (DI 947/951).

2001 DI air compressor rebuild

This is a great guide... but since it's for a PWC, the steps might be different. It seems like I can remove the piston by removing the compressor cover and rotating the engine so that the piston sticks out. How does one do that exactly on my model? It might be a dumbass question but I assume you do this manually and not using the starter. Any help is appreciated.

 

[POPPS]

You are correct,,,remove the spark pugs, and rotate the motor by hand,..

 

[despower]

Ok, I got it now. I'll post some pictures when I start at it.

 

[POPPS]

There is a sleeve that goes thru the piston.take careful note of its orientation..it has a very slight taper that is hard to see.,,

 

[despower]

To clarify... So the sleeve isn't symmetrical? There's a taper on one side? Ok, I'll take note when I remove it. I haven't pulled the piston yet... Was going to do that tomorrow.

 

[POPPS]

Its a little hidden note in the manual..based on flywheels,,,i am imagine the wide side logically faces out,,take a pic before you remove it.

 

[despower]

I have the head of the compressor off now. some photos to show what it looked like when removed.

 

[despower]

No some photos of the disassembled head. There are no blemishes on the head at either end that would suggest a leak. The o-ring and gasket are uncompromised - at least by eye. I have new ones on order. The inlet and outlet reed disks are pristine.

 

[despower]

The pressure hose also looks OK. The piston looks a bit cruddy, but undamaged. Next is to pull the piston and sleeve. Still unsure how to rotate the engine with the plugs off, but I'll see if I can YouTube that.

 

[despower]

I pulled the sleeve out... and now I realize that once you pull the sleeve, you can't put it back on without removing the piston. Dooohhhh. I guess I'm all in now. You can see photos of the sleeve and piston. Piston looks a bit corroded at the top. I think it might have sucked in a bit of water through the leak when my bilge pump failed (see other thread on bilge pump). I've got a new (used) sleeve and piston on order, but I don't think this is the problem. Sleeve looks undamaged and the piston looks fine other than the small bit of corrosion.

 

[despower]

So now I have to pull the piston so I can put the sleeve back on... the only way I can see to do that is to remove this cover (via the two hex bolts). Can someone with more brains than me confirm that this is how it's done? This is really hard to get at but I am hoping that it's easy to remove the piston arm once the cover is removed.

 

[despower]

This picture is from the PWC thread mentioned above. I assume that once the cover is removed, this is what I'll see.

 

[despower]

Really need some help here... I've finally gotten around to trying to remove the compressor piston and have run into a roadblock. I can't seem to be able to remove the counterbalance end plate for access to the piston rod. The PWC thread mentioned removal of the PTO cover, but after removing the 6 hex bolts for the PTO cover (with great difficulty), it doesn't seem to budge. The pictures show a closeup of the end plate (right) and the location relative to the PTO cover.

Does anyone know if I should be able to remove the end plate without removing the cover? It comes out part of the way, but not all.

 

[despower]

Managed to remove the end plate without removing the PTO cover... which I think would have required me removing a lot more things. Picture shows it's pretty cruddy inside... that's what I get for operating the boat in salt water.

In any case, I'm stuck again because I can't get the bolt out at the end of the piston rod. I've sprayed penetrating oil on it for the time being. I'll wait a while and try again... any tips for getting this out would be appreciated.

 

[despower]

Also having trouble locking the engine rotation so it's easier to remove the piston bolt. Tried the rag in the spark plug hole... didn't work so well. There must be a better way.

 

[despower]

So finally some success... managed to jam enough rag into the cylinder to stop the engine rotation. I would appreciate if anyone can suggest an alternate to do this. Seems a bit half a$$ of a solution. Got the hex screw out with a socket allen key... a regular allen key just didn't give enough torque.

Piston looks fine with some slight corrosion at the piston end. The piston rings broken when I tried to pull them off - and part of the top ring was missing. Not sure if I broke that removing the piston or if it was already broken. I have new rings on order in any case. So, I'm all set for the rebuild once the parts come in. I'm on the extreme east coast so it takes a while for parts to be delivered. Expecting to finish this middle of next week.

 

[POPPS]

No need to remove the pto cover and the 6 hex bolts.,,be carefull putting the rings on,,,they do not expand much,,,and will break.

 

[despower]

Replacement piston and rings arrived today so I have that installed on the sleeve now. Piston seems to be working fine... pushes air as expected. Installed on the counterbalance shaft and all seems fine.

Note that I am having trouble reinstalling the end plate... that was difficult to remove and it seems even more impossible to reinstall. I don't want to break it and banging it back in place with a rubber mallet isn't working (not enough room). Any tips on reinstalling that? Maybe some heat to make the cover a bit more pliable? Compressor gasket and o-ring arrive tomorrow so I'd like to install it at the same time.

 

[despower]

So, now having pulled apart the entire compressor, I will rant on the following.

My dealership did a pressure test on the compressor, and from that they recommended replacing just about everything - injector hose, compressor head, body, reed valves, piston, sleeve, etc. It amounted to over $1600 if these parts were even available new. They didn't bother to open the compressor to have a look... they just said "replace it all." And they charged me $400 bucks for this.

So now that I've opened it all up, the only thing I could find wrong was the one of the piston rings, and I think I busted that while manually rotating the engine with the sleeve removed. Piston, cap, body, valves, hose... all were in pristine shape. So, I replaced the gasket and o-rings on the compressor body and injector hose. That was no more than $40 in parts, and in the meantime, I ordered a whole bunch of extra unnecessary parts from e-bay just in case there was a problem with them.

So, I say - what the heck?!? Are all dealerships this lazy? I can't imagine they are underhanded, but really? Recommending replacing parts without really having a look?

I'm a bit stuck because there's only one dealership in the city and not too many are interested in servicing a 15 year old boat.

All I can say is thank you to forums like this who can help.

Des

 

[POPPS]

That is ridiculous!!!