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Discussion Starter #1
I have 1998 Yahama GP760 that I got last year. It’s a 2 stroke so I know some smoke is normal. But when should I be concerned with the amount coming out the exhaust? Toward the end of the season it seemed to be smoking more than normal but nothing too crazy. Does anyone know any resolutions to fix it? Thanks!
 

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Ekelly24,
Welcome to the forum.
I'm going to assume that your still running on the injection pump and not premixing. The pump on your ski is a fixed ratio pump. If a lot of time is spent idling or in no wake zones. The motor will load up with excess oil and smoke heavier then normal. This should clear though once you open it up out on the water and run for a few minutes at higher rpms.

The oil being used is another factor. There are low smoke oils available that can cut the smoke to almost unnoticed. Those that are, advertise as such. Amsoil makes several, and I think Pennzoil has some. You'll just have to find one that meets requirements (tc-w3) and is convenient for you to get. Then switch to it. You'll want to run the ski almost out oil or drain the tank to switch over. You really shouldn't mix large quantities of different oils. A few ounces is permissable. The other thing is to not get any air bubbles in the feed line to the pump. This is not an issue if you don't completely empty the tank. Or you can bleed the line from the screw on top of the pump. Simple either way.
 

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Dave in DE,
Thanks for the response. I am still using the injection. I have seen that some people do away with it and use premix. Would that be a benefit? There doesn’t seem to be anything wrong with the pump as of now.
I will look into different types of oil as well. I really noticed a lot of smoke when I was at idle speed for a while so wasn’t sure if that was normal or not. With your explanation it seems like it is. I appreciate the information you’ve provided!
 

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Sorry, I answered your message kind of muddy.
Yes, extended idling will cause it to smoke a bit heavier.
I have a 93/94 vxr pro both run the Yamaha oil and smoke heavy coming in through the no wake zone. (300yds)
Quicksilver makes a low smoke pwc oil. Quicksilver is sold at Walmart so you may be able to get it there or order it through them or the Marine out fit in pic below.

Most got rid of there pumps for fear of pump failure. It's a rarity though that a pump fails. 99.9% of the time it's an oil line failure. Due to lack of proper maintenance. The lines from the pump to carb get hard and shrink. These hoses then either break or pull off. If your injection lines feel hard/stiff replace asap. Or do a pump block off and go premix. I prefer injection because you don't have to carry a messy oil bottle to mix from when getting fuel on the water. And a tank of oil lasts several tanks of fuel. so you fill oil every 5/6 fuel tanks. To me much less mess.

Replacing the oil lines is easy. You can get 1/8" tygon from SBT or weed eater fuel line from a small engine (lawnmower) repair shop. Re-attach with wire ties and a tie wrap gun from Lowe's. The gun is the only way to get them tight enough to get them to hold and seal.

Then you have to bleed the system. Once the pump is bled. Then you have options for the rest of system. You can either use a large syringe (again from Lowe's small engine section.) And push oil through the line to carbs before attaching lines at the pump. (From pump to carb)

Or drain the fuel tank and premix about 3 or 4 gallons at 40/1. And ride till oil comes up to carbs. Then fill the tank to dilute the premix. (Won't take long)

The 3rd option requires removing the pump and using a drill to turn the pump and push oil to carbs. This is the best option only if you have pump already off and rebuilding entire system. (Will need pump gasket)
 

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Great info Dave. I really appreciate the time to explain it in detail. I have not checked my lines so I will make sure I do when I get it back out this year. Maybe another month or so before that happens.
 
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