Black oily Plugs. VRO problem?

[Hardcore]

this problem is killing me. 1991 115hp V4 johnson. idled rough and would miss badly sometimes killing it. So i dissassembled and cleaned the carbs. they looked really clean so i put them back on. Fired it up and now it runs even worse, barely runs, idle fluctuates wildly and when i pulled the plugs they were fouled badly oily and black and the top of the cylinders were too.

seems to run very rich but i cant see why, i didnt adjust anything and it all seemed so easy. there are no adjustments. I've rebuilt many carbs too. i hooked up a timing light to check spark and it was very consistent.

also the water from the pee hole was cold is that normal? thanks

the manual talks about some air bleed valve as a possible reason but i dont know where that is.

all 4 plugs were the same. and it spits back and will miss at all speeds although less so at high rpms.

 

[Dhadley]

Re: Black oily Plugs. VRO problem?

What plugs are you using?

 

[Hardcore]

Re: Black oily Plugs. VRO problem?

champion 82

 

[Hardcore]

Re: Black oily Plugs. VRO problem?

also tried ngk 7

 

[emdsapmgr]

Re: Black oily Plugs. VRO problem?

The engine could be running cold-are the thermostats stuck open?

 

[tashasdaddy]

Re: Black oily Plugs. VRO problem?

check compression, it was built to run on Champion QL77JC4 or Champion QL16V

 

[Dhadley]

Re: Black oily Plugs. VRO problem?

QL82C or QL82YC?

 

[HighTrim]

Re: Black oily Plugs. VRO problem?

Do a thorough decarb, then service your recirculation check valves and pulse limiter. Torque proper plugs to 18.5 to 20.5 ft/lbs

Decarbon instructions here in the FAQ: http://forums.iboats.com/showthread.php?t=158076


Did you ever get the compression numbers. Bottom cylinders lower than top by any chance?

 

[Hardcore]

Re: Black oily Plugs. VRO problem?

QL82C or QL82YC?

the YC

 

[Dhadley]

Re: Black oily Plugs. VRO problem?

Ok, lets get the right ones in there. The extended reach will cause some problems down the road, if they haven't already. Personally I'd run the QL77JC4's. If you insist on the 82's you may want to rejet a little. They burn pretty hot in that motor.

Once that's done we can look at the carbs. You said you pulled them off and it ran worse. Did you do a snyc-n-link upon re-installation?

 

[yamamarinetech40]

Re: Black oily Plugs. VRO problem?

You say 'they(carbs) looked really clean so I just put them back on'?? Didn't clean the carbs? And all cyls. are running way rich? Gee....nobody else caught this?

 

[yamamarinetech40]

Re: Black oily Plugs. VRO problem?

oops...my bad...but did you test the needle and set float hieghts?...that phrase "they looked clean" is what got me...

 

[Hardcore]

Re: Black oily Plugs. VRO problem?

i still cleaned them and checked all the jets and passages and they were clean. the float was correctly set.

 

[Dhadley]

Re: Black oily Plugs. VRO problem?

OK, we're back to my question -- after the re-install did you do a snyc-n-link (reset the carb linkage, cam foller, roller and throttle arm)?

 

[Hardcore]

Re: Black oily Plugs. VRO problem?

i guess not although i looked at the linkage and they do seem to shut and open at the same time and i can hear the plates hit their stop. maybe thats not enough?

i wonder what is causing the sudden missing and the erratic rpms? i tested for air leaks with a propane torch and couldnt find anything. i wonder if the vro is putting in too much oil?

 

[Dhadley]

Re: Black oily Plugs. VRO problem?

First -- put the torch away.

Now, disconnect the throttle cable. Then loosen the screw in the middle of the linkage connecting the top & bottom carb. Make sure the throttle arm on the side of the block is back far enough that the cam follwer is not touching the roller.

Have you got the right plugs yet?

 

[Hardcore]

Re: Black oily Plugs. VRO problem?

i'll be hitting it hard thurs with the right plugs, link n sync etc.thanks, the torch was unlit of course,

 

[rodbolt]

Re: Black oily Plugs. VRO problem?

another note, let us know if the fuel bowls are the black plastic(minlon) or cast aluminium.

 

[Dhadley]

Re: Black oily Plugs. VRO problem?

i'll be hitting it hard thurs with the right plugs, link n sync etc.thanks, the torch was unlit of course,

Ahhh, good idea. Shooting raw gas all over a motor that's running. I guess if there was spark arcing somewhere that would certainly pin point the place.

 

[Hardcore]

Re: Black oily Plugs. VRO problem?

another note, let us know if the fuel bowls are the black plastic(minlon) or cast aluminium.

plastic, minlon according to the manual