injection problem

Hello everyone here at I boats. It has been awhile since I have been here and I hope you can help!!<br />I have a 1989 Yamaha 175hp Model 175ETXG<br />The mercury switch has gone on the oil injection and I really don't want to depend on a 14 year old injection system?? I have been mixing the oil 50 to 1 in the tank most of the summer. The problem is that the plugs will foul out in about 4 to 5 trips. I asume it is because the injection mixs from 200-1 to 50-1 depending on speed. Now I do all kinds of fishing with my boat from slow troll to WOT. How Can i stop this?? I was thinking of going to a hotter plug?? I have changed from NGK to Champion and that has seemed to help a little but no were near were I should be. Champion plug is QL78C next step is a QL86C<br />Am I on the right track?? or should I fix the injection?? Any other sugesstion??<br />Thanks all!!

Re: injection problem

hello<br /> now you know why all the engine manufacturers spent millions working on oil injection. test the plug caps if they are red. test the recirc valves.check the stator output voltage.were it me I would opt to repair the system. a small amout of repairs now may save a motor later. remember nothing lasts forever.<br /> good luck and keep posting.

Re: injection problem

Thanks rodbolt, All them things work fine! It is the mercury switch on the side on the engin with the emergency pump switch. I have check the tank float switch and that seems to be fine.<br />So it is just a matter of replacing that black box.<br />But as you say nothing last forever!! And that is the problem, I have a 14 year old injection system that has no warning that it has stoped pumping oil!! The only way I will no is when the motor goes BOOM!!!<br />It will tell me when it runs out of oil in eaither tank, but nothing about poumping ?? So this is why I was thinking I would just mix for now on and not worry all the time if its working. But the mix is right for WOT but not for trolling, this is why it is fouling the plugs. I was just trying to find a better way, IE: Hotter Plugs ect ect.<br />Thanks for respond!! I will think about fixing it, but still looking.