XR2 Black Max fowls plugs

[tbrownarcher]

Red face XR2 Black Max fowls plugs

Our boat is a 1999 18 ft Triton 180 Premier.
Our motor is an XR2 Black Max 150 HP.
The Serial # is B176785

Our motor fowls the plugs and then it's of course hard to start and does not run really well for quite a long time of full throttle. The motor does clean the plugs or heat up enough to run well after a long time at full throttle. We can also take the plugs out and clean them with spray on carburetor cleaner which makes it run like crazy.

What is happening is that we have to idle the motor a lot because the lakes around here are no wake or 5 mph for the most part and so we are not able to send it flying like it needs to be.

We disconnected the oil pump and run without the pump mixing the gas/oil ration ourselves. We do this with a critical eye at a 50:1 ratio which is what we understand it should be run at. The motor being a 1985 we don't want to be running it when the oil pump goes out and can't afford a new one. We don't trust a new one either so we prefer to mix the oil and gas. Oh yeah! we fill it with regular gas (no alcohol).

The obvious question is what can we do to fix this? Since we would do the work ourselves we also need any tips to do the work that anyone thinks may be helpful. We will buy the OEM book.

Thanks,
Nate

 

[j_martin]

Re: XR2 Black Max fowls plugs

The original setup leaned the oil mix to about 100:1 at idle. You may have a tough time getting it to idle at 50:1 for long periods.

You could try to lean out the setup to the max safe spot. Usually they are set up a bit rich from factory. A lot depends on altitude and fuel, and the individual engine, ie individual cylinder timing.

1. Start with a full formal link-n-sync. Gives you a base line and makes sure timing is right through the range. Wouldn't hurt to go through the carbs, cleaning them, refreshing gaskets, and setting the floats spot on. If they are foam floats, find a set of later WH(anything) carbs on eBay to get replacement hard plastic floats.
2. Set your mains mixture by performing a full throttle cut off after a decent run with fresh plugs. Should be shopping bag brown. You may be able to make some or all of the main jets smaller.
3. If it still punches out of the hole OK, you may be able to lean out the idle jets a bit. (bigger jets). If it balks a bit at a slight increase in throttle, sometimes setting the throttle cam pickup a bit later helps. Watch out for running hot at low rpms.

hope it helps
John

 

[Faztbullet]

Re: XR2 Black Max fowls plugs

I agree with John that the 50:1 mix is hurting ya but several other things could be wrong to cause it to foul plugs. Check the following also: T-stat that are stuck open allowing engine to run to cool, wrong plugs ( I used NGK BU8H on non oilers), recirc valves dirty on intake, engine trimmed (exhaust ports buried)to low on long idles

 

[tbrownarcher]

Re: XR2 Black Max fowls plugs

Yes!!!!!!!!!!! It's actually oil that fills the hole maybe a bit of carbon but it's mostly liquid. So, it's not carboning the plugs it's just filling the hole with oil. Sorry about the description ...

Nate

 

[Faztbullet]

Re: XR2 Black Max fowls plugs

Check/clean or replace recirc valves. They are under carbs on the intake and have small hoses attached. Remove the hose with long nosed pliers and check spray pattern, it should spray a fine mist while idling. If its blobs of fuel or dribbles out valve its dirty and cleaning it may fix it. These take excess fuel puddled under the reeds and send it to another to be burnt. If these are bad engine may stumble when accelerating as excess fuel(non atomized) is thrown into crankcase and fouls plug..