OILY PLUGS in 90HP Evinrude VRO 1996

ronmeijer

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I have done 6 hrs on a fully recon 90HP 'rude on a 17'6" lightening. running a 25:1 mix (50:1 VRO & 50:1 premix) as per mechanics instuction to 8hrs. I experienced a sudden drop in revs from 3500 to 2000rpm. The motor idles sweet but under load won't top 2000rpm. The plugs are very oily. Can this cause a drop in power. I am running champion QL77JC4. Do I need to use a hotter plug for running in? or am I using the right plugs? Could the spark leads be breaking down also and what leads should I be using if this is the case? Thank you in advance for your replies.
 

walleyehed

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Re: OILY PLUGS in 90HP Evinrude VRO 1996

Welcome aboard, Ron....I'd say you fouled a plug.<br />QL77JC4 is fine as well as a QL82C. I would gap them at .035-.040 for break-in and see if that helps.....The plugs were new I assume????<br />I may be wrong, but I'm eliminating the carbs as a problem due to all plugs being loaded with oil, which brings me to another point....are you sure you mixed 50:1 in the fuel, or could you maybe have mistakenly went 25:1 with the fuel??
 

ronmeijer

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Re: OILY PLUGS in 90HP Evinrude VRO 1996

Thanks walleyehed. I am running 50:1 through the VRO and I am also premixing 50:1 in the fuel tanks while I am running in the motor which was instucted by the mechanic for 8 hrs. Does this sound like the right thing to do?
 

ronmeijer

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Re: OILY PLUGS in 90HP Evinrude VRO 1996

Hi again walleyehed. Could you please tell me the proper proceedure in running in this motor. ie: how many hours, at what RPM, do I go straight back to 50:1 or do i gradually reduce the mix from 25:1 to 50:1. I'm a first time runner inner on the water.
 

walleyehed

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Re: OILY PLUGS in 90HP Evinrude VRO 1996

OK, if you are running with a VRO oil pump, fill oil tank with oil. Mark a line where the oil is at in the tank with a thin-line permanent marker. fill fuel tanks with pre-mix (50:1) 16ozs. per 6 gal fuel.<br />First 5-10 min. at fast idle, 1500RPM. Check operation of water pump, strong stream from tell-tail.<br />First hour, get on plane, but do not exceed 3500RPM.<br />Hour2: bring boat up to planing speed and back off throttle to 4000RPM. during this second hour, every 5 minutes, or so go to wide open throttle for a period of 45 seca. to 1 min. backing off to 4000 rpm between intervals of WOT.<br />Hours3-10: avoid full throttle operation for periods in excess of 2 minutes, and vary engine rpm every 12-15 minutes through-out the RPM range.<br />After hour 10: check oil level in VRO tank to see if oil is being consumed.<br />NOTE: If you are using premix only, mix at 25:1 for the first 10 hours, and 50:1 after that period.<br />If verification of oil use is made from VRO tank, refill to mark, and run straight fuel in tank.<br />At approximately 10 hours, retorque Cylinder head bolts after running, but has cooled to the touch.<br />It is not stated in the manual, but for the next 5 hours after this, I never run WOT for more than 5 minutes at a time, until after 15 hours.<br />Prop as needed to acheive approximatly 5800 RPM with a light load at WOT. 6000RPM with the same load would be even better.<br />Hope this helps, and I would recommend a good quality oil, such as Johnson/Evinrude XD-25, although there are other great oils out there, I recommend Factory only oil for the first 25 hours, and in my case, the life of the engine.<br />Good luck!
 

seahorse5

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Re: OILY PLUGS in 90HP Evinrude VRO 1996

First of all we need to determine which 90hp you have, the 60 degree or the 90 degree crossflow as they use different sparkplugs. If you can see the flywheel and the starter drive gear, then you have the crossflow and should use QL82C plugs. If there is no flywheel in sight, then you have the 60 degree block and should use the QL78YC plugs. What is the complete model number on your motor?<br /><br />Since it will not get above 2000 rpm, it could be in the SLOW mode, thinking it has an overheat condition. You may also have lost ignition on one bank, or even had carb linkage come loose. You will have to do a bit of troubleshooting to see what happened. Might start with a compression check to make sure everything is OK internally. Did the person rebuilding it give you a warranty?
 

walleyehed

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Re: OILY PLUGS in 90HP Evinrude VRO 1996

seahorse, I am by no means an expert on year production, but I though the eagle-series started in 97'. I'm assuming they came before this then????? :)
 

seahorse5

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Re: OILY PLUGS in 90HP Evinrude VRO 1996

1995 for the V4 and 1991 for the V6.
 

ronmeijer

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Re: OILY PLUGS in 90HP Evinrude VRO 1996

Hi guys,<br />Still no joy after your suggestions. When not under load she runs fine, smooth and doesn't miss a beat. As soon as she's in the water 2Krpm is all I get. Could it just be the plugs or could something be breaking down under load. What is the difference between the QL77JC4 which is what I'm running and the QL82C? The 'rude is 90% crossflow.
 

seahorse5

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Re: OILY PLUGS in 90HP Evinrude VRO 1996

Shouldn't the motor be a 100% crossflow? :)
 

seahorse5

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Re: OILY PLUGS in 90HP Evinrude VRO 1996

OMC changed their plug recommendations back in 1996 or so. The QL82C is slightly warmer and will not foul as quickly as the 77's.<br /><br />Use a timing lite and connect it to each plug wire at the 2000 rpm and see that each plug has ignition. You can disconnect the tan wire from the power pack and run it up to see if a short somewhere or a sensor is telling the motor to go into the SLOW mode. Pull the air cover and make sure the throttle plates are opening fully. Check that the spark advance plate moves when the throttle is advanced.
 

seahorse5

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Re: OILY PLUGS in 90HP Evinrude VRO 1996

You might want to a compression test first, just to be sure there is nothing internally wrong.<br /><br />Did they clean and rebuild the carbs during the overhaul?
 

waterinthefuel

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Re: OILY PLUGS in 90HP Evinrude VRO 1996

This may sound a bit simple, but how about cleaning the plugs and trying it again? My little engine fouls plugs like crazy. I clean them and I'm good to go for another few hours. I'd start with simple first.
 

ronmeijer

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Re: OILY PLUGS in 90HP Evinrude VRO 1996

Good news. After all that it was the port power pack breaking down. Put a second hand one on, Now she's the rocket she mean't to be.<br /><br />Next Problem!<br />After a week of exellent running she now feels like she's spinning in mid air. She use to plain at 2500rpm. Now she rev's straight to 5000rpm and sounds and feels like the prop is slipping. At 4000rpm she will slowly come back to 3000rpm as she "grips" in the water but dosn't increase speed once WOT is reached. :(
 

walleyehed

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Re: OILY PLUGS in 90HP Evinrude VRO 1996

I may be wrong, but it sounds as though you spun the hub in the prop....?????<br />Sounds like prop-shop time, but see what some others think too.....
 

ronmeijer

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Re: OILY PLUGS in 90HP Evinrude VRO 1996

Hi walleyehed.<br />Happy New Year. I don't know alot about outboards, Could having the motor recond cause strains on older parts of the motor, if the hub is screwed, what could be next and what should I get my wrench to check for.<br />Cheers Ron :cool:
 

walleyehed

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Re: OILY PLUGS in 90HP Evinrude VRO 1996

If you tell me it used to plane at 2500, and now you say it goes to 5000, and slowly comes back after planing, I say the hub is spun. take the prop to your mechanic and let him look at it....sometimes a good eye can see the rubber insert has moved.<br />I assume you are taking off with engine trimmed clear in (down).
 

Knightgang

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Re: OILY PLUGS in 90HP Evinrude VRO 1996

Sounds to me like a spn prop, like a slipping tranny in a car.<br /><br />Just because the engine was recond, it no need to worry about other parts. I have seen brand new engines spin props. Have yoru prop checked and you should be good to go. I have a spare prop in my boat, just in case.<br /><br />Knightgang
 

ronmeijer

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Re: OILY PLUGS in 90HP Evinrude VRO 1996

Cheers for the info, If the prop has spun I will diffinately buy a spare even though I have an AUX on the boat. :)
 

Hooty

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Re: OILY PLUGS in 90HP Evinrude VRO 1996

Yo, Ron...<br />I don't know if you know it or not but if the hub is spun out, it (the hub) is replaceable.<br /><br />c/6<br />Hooty
 
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