Rotary Valve Cover question and a SBT engine

[fourmyskull]

Question, I have a1998 Seadoo GTX RFI that I have a SBT refurbished engine. I pulled my rotary valve cover off my old engine and there are small scratches on surface of the cover. The rotary valve plate looks fine. I will attach pictures to this post of both of them.

My question is, SBT wants 156 bucks to resurface a used one and its 10 to 15 days out. Is this something a local machine shop can resurface for me or do I just need to wait for SBT and pay the 156 bucks and send my core to them. The scratches can barely be felt by your finger nail.

Other question while I have the engine out of the ski and installing a new one is there anything else that I should check? My starter is strong however there is a starter/alternator shop down the road from me that I think I will have the starter gone through since the motor is out.

Any suggestions is highly appreciated.

Thank you

 

[fourmyskull]

Question, I have a1998 Seadoo GTX RFI that I have a SBT refurbished engine. I pulled my rotary valve cover off my old engine and there are small scratches on surface of the cover. The rotary valve plate looks fine. I will attach pictures to this post of both of them.

My question is, SBT wants 156 bucks to resurface a used one and its 10 to 15 days out. Is this something a local machine shop can resurface for me or do I just need to wait for SBT and pay the 156 bucks and send my core to them. The scratches can barely be felt by your finger nail.

Other question while I have the engine out of the ski and installing a new one is there anything else that I should check? My starter is strong however there is a starter/alternator shop down the road from me that I think I will have the starter gone through since the motor is out.

Any suggestions is highly appreciated.

Thank you

In addition to this information, I have two of these skis same year model everything.
1998 Seadoo GTX RFI
One has a SBT motor in it with about 50 hrs on it. This one starts and runs good out of the water but when place in the water looses all power will hardly run with the throttle wide open. I have replaced the Fuel pumps in both skis visually check the fuel injectors they are spraying good, however that was just visual test.
I assume this is a rotary valve issue, however have not checked it. Which moves me to the second engine

Second engine, the rotary valve cover pictured above, had the same issue however was worse. Sometimes you could not get the ski to start after running it for awhile. Granite I did try other plugs yes I feel like I should disclose that. This motor was the original engine 1998 and has very little compression.
I ordered the new motor from SBT, I have the new motor and that is why I have the rotary valve removed in the above pictures.

So I was hoping during the process of getting the old engine out of this ski and the new engine installed that I would see what was causing my power loss when placing the ski in the water so then I can fix it on the first jet ski that has the engine with about 50 hrs on it.

ONE LAST Question, lol when removing the engine, I pulled the shaft out of the out with the engine by accident. I did not damage the shaft it just needs reinstalled. The directions for removing the engine said to be careful not to do that. Was the directions just telling me to be careful however not a big deal or is it a big deal?? Just preparing for the reinstallation

Thank You

 

[fourmyskull]

So I spoke with a machine shop, this guy did not know a whole lot about the engine. He told me I could polish the rotary cover with a little oil and sand paper with how little the scratching was. Use 320 then 700 then 1000 grit. Does anyone have a opinion on this?

 

[clegg]

I would think you could refinish that. Just use the self adhesive sandpaper on a piece of glass for a super smooth perfect finish.

 

[POPPS]

Does the motor start well,and run right on the trailor without water.?,,
If you run water thru it on the trailor does it run like crap?,,,if yes...you may have water going into the cylinders,,
Have you load tested the battery,,,a weak,battery will be a champ on the trailor and a "chump"in the water under hydrodynamic load.
Make sure all your large connections from the battery to the selenoid to the positive on the starter are secure and clean.
Do a draw test on the starter,

 

[etemplet]

Shallow scratches shouldn't be a big problem on the cover plate. What you need to be concerned with is wear. Place a straight edge across the rotary valve cover plate and check with a feeler gauge. You'll see wear, if there is any, near the ports (the round holes). Even so... a little wear isn't going to stop the engine from running properly. The cheapest route, if you think your cover is bad is to buy one off ebay. Don't nit pick these engines, they don't need it. That stuff about 320 grit and 1000 grit is not necessary. Polishing it will only make the surface uneven unless you're really good at it and I'm not.

Machining the rotary valve surface is not that simple. The same amount of material removed needs to be removed from the gasket surface and the o-ring groove bottom. I've done a few in my lathe so I know a bit about them. This cover was worn a good bit. Chances are... yours is fine. Good Luck !!