disconnect oil injection on 98 90 yamaha

bonitoman · #1 November 28th, 2003, 02:54 PM

What needs to be done to disconnect the oil injection system on a yamaha 90 hp. I will premix just like i have done on all omc engines. I see the electical connections that need to be disconnected. What on the pump or block needs to be plugged or removed. Thanks.

BRIAN03 · #2 November 29th, 2003, 01:16 AM

WHY Yamaha has made the best oil injection system on the market. The oil is injected in to the intake manifold for a reason. Yamaha has spent alot of money designing this system. It works great and supplys oil to engine based on throtle position. Would you pull the fuel injection system off your car and put a carb back on it. Other than a sensor problem once an while this system works well. You will use alot less oil too.

rodbolt · #3 November 29th, 2003, 03:02 AM

hello

yep what he says. I would not pull the precision blend system from that yammy. maintain it service it look at the clip that attaches the link arm to the pump. some white ones in the 98 99 had some problems with cracking. but overall its a very rugged and reliable system that will allow for some carb leanout without scuffing pistons. I would recomend replacing the fuel pump diaphram every 3 years . do this before it fails. a leaky diapham will waste a pistion on most oil injected motors due to the raw unmixed fuel diluting the oil. so if I were maintaing this motor I would sweat the oil tank cleaning once a year and the fuel pump. both are totally simple.both can make you frown. but I like oil injection due to the more precise oil control. most premixers have a tendancy to give a little extra. extra oil can do almost as much damage as no oil, it just takes a bit longer.

good luck and keep posting

bonitoman · #4 November 30th, 2003, 01:27 AM

I still want to disconnect the oil injection system. What needs to be done. I know yamaha makes great engines. I just do not like oil injection systems and will always premix.Thanks

rodbolt · #5 November 30th, 2003, 02:32 AM

hello

if you wish

what I would do then is remove the pump leaving all lines attached. withdraw the pump driveshaft. reinstall the pump and lines. remove the oil resevor and cap off the line at the pump . unplug the wiring. test the overheat alarm and go like mad. you may find the motor harder to start due to the oil in the fuel. you may have to open the fuel mix screws 1/8-1/4 turn. dont let fuel sit over 30 days in the bowls. if those touchy little mikunis or kiev's run just a tiny bit lean due to trash or oil varnish. POOF

no piston skirts.

good luck and keep posting.

bonitoman · #6 November 30th, 2003, 03:26 AM

Thanks Rodbolt for the info. MY question is for the pump driveshaft. I see a driveshaft in the engine that comes out of the block and in the pump itself looks like a drive shaft and a gear with teeth. Which component do I remove? Thanks Also do I need to cap the lines oil lines that go to each carb.