Sport Jet plastic gear in oil injection pump

[Oode]

I've heard a lot about a plastic gear that drives the oil injection pump that is a common failure and eats engines. I looked on an exploded parts diagram and cannot find any mention of such a thing, perhaps I'm looking in the wrong digram??

I've got the '96 120 XR and would like to be proactive.

Also, any comments on the pros/cons of blocking off the injection and using premix...?????

 

[kend301]

Re: Sport Jet plastic gear in oil injection pump

Let me track down the parts pics and I will PM them to you as they take you out of the IBoats site . Nothing wrong with going with premix , It is just more smoke at idle . The gear problems they had were with early ones (late 94 , 95)
If you want to go with premix 50:1 is the correct ratio.

 

[Daley]

Re: Sport Jet plastic gear in oil injection pump

I'd be interested in those diagrams too, if they apply to my 97. I certainly don't mind replacing it BEFORE it fails - I figure it's lasted this long, so the next one would probably last at least another ten years.

Thanks for all your help on these engines!

 

[kend301]

Re: Sport Jet plastic gear in oil injection pump

Pic coming soon.. I can't download the pages from the site I use so I will hook up the old faithful scanner this weekend and post the pic .

 

[kend301]

Re: Sport Jet plastic gear in oil injection pump

the following is from a 90 hp 3 cylinder but the gear is in the same place , It is labeled number 3 on the bottom of the crank .

 

[Daley]

Re: Sport Jet plastic gear in oil injection pump

Wow, so it's not as easy as I thought. Somehow I pictured something external to the engine, but a picture is worth a thousand words...

Thanks Kend301

 

[kend301]

Re: Sport Jet plastic gear in oil injection pump

Yes it really sucks that the gear is the first thing you put on the engine during a rebuild , Plastic also makes no sense , should have gone with Brass and a plastic gear on the oil pump shaft so you could pull the pump and fix it ! .. Just my opinion .

 

[Oode]

Re: Sport Jet plastic gear in oil injection pump

Wow, not what I was hoping for.... so, since I don't want to do an engine rebuild....

Is there any early warning if the oil pump shuts down??? Or is it straight to the machine shop....

The conversion to premix is looking better and better....

 

[Daley]

Re: Sport Jet plastic gear in oil injection pump

The conversion to premix is looking better and better....

Man as many times as I've seen it recommended (and it makes good sense), I'm still stuck on the fact that it's gonna be a PAIN to premix 15 gallons. Any suggestions?

 

[kend301]

Re: Sport Jet plastic gear in oil injection pump

Both of your boats have a low oil alarm However , if the gear fails , it will be a MasterCard moment if you know what i mean . Pre mix is no big deal , spend a few extra bucks and get 4 bottles at Wal Mart that will treat 6 gallons each , use them , then you can fill them to 375 ML which is 48.9:1 ratio and still have room for Stable Ethanol treatment , each bottle will treat 5 gallons .

 

[Oode]

Re: Sport Jet plastic gear in oil injection pump

Think I may go that route, is there a plate you have to put over the injection port??? (I know on other pwcs it's required..)

On another note, just got back from the maiden voyage, got a surprise bonus, my boys were free so we all went to the lake to test her out. While doging the thunderstorms here in central NC, we had a few good runs on the tubing, but on the way in we lost power, good at low revs, but trying to power up it just sputtered.... just now rinsing out the bilge, there was a strong smell of fuel in the bilge... any ideas??? Supposedly the fuel lines were just replaced last year...
oops, just realized I should start a new thread... I'll go do that now..

 

[kend301]

Re: Sport Jet plastic gear in oil injection pump

Yes you will have to get a plate over the injection pump mount , do you have any access to someone with a shop that could make one for you ?

 

[Oode]

Re: Sport Jet plastic gear in oil injection pump

Yes, I can get one made, I work with a machine shop on some of my consulting projects... I just dont' think I can afford a one off..... no biggie.. Maybe I"ll have 10 made and sell them... I'm guessing there isn't much to it..

 

[rodbolt]

Re: Sport Jet plastic gear in oil injection pump

most folks pull the pump,pull the driveshaft and reinstall the pump.
cheaper than making a cover.
been a long time since I played with a sport jet, they didnt like saltwater at all.
\

 

[Oode]

Re: Sport Jet plastic gear in oil injection pump

What did it not like about salt water???

 

[rodbolt]

Re: Sport Jet plastic gear in oil injection pump

corrosion.
made maint difficult.

 

[kend301]

Re: Sport Jet plastic gear in oil injection pump

RodBolt speaks the truth , Mine had been run in salt water prior to me buying it and getting the drive apart to service the stator , check the wear ring was a nightmare the first time had to drill out and tap 4 bolts between the gate , stator and wear ring. The intake grate was also very hard but I got lucky and did not snap any of them .. RodBolt , Have you ever used Hylomar on threads in salt water applications to keep them from corroding ?