Out on the boat- need some help

[Cady8special]

Out on the lake now. Bought a boat a month ago. 1999 135hp carbed merc. Been using for a month idling at 650 in gear. Added fresh oil the other day- a gallon into the resovoir. After about 30 minutes of running the motor started idling much higher. Picked up about 300 rpms at least. Could that be from the new oil? Old stuff maybe sludgy or what? I had to unscrew the linkages and drop the idle that way. Is there anything else that would make the idle increase like that? Clogged carb that cleared? Any help would be great. Ty

 

[MikDee]

Running lean! running out of fuel. It sounds fuel starved.

 

[Cady8special]

I have plenty of gas - what else would cause me to run lean - assuming that's the problem. Could the oil have anything to do with this or no?

 

[MikDee]

No! You may have plenty of fuel, but the engine is not getting it! Are you stuck? Here try this, try starting it, if it goes to stall pull out the choke, if it speeds up, or continues to run, this would confirm it!

 

[Cady8special]

I actually pushed the choke to drop the rpms before putting it in gear. I adjusted idle down and ripped across the lake at wot with no issues. Idling fine now after adjustment. Just makes no sense to me. Could the carb have been gummed up and just now cleared?

 

[Dukedog]

First thing I'd check (get rid of) is idle stabilizer. That's after your done and home safe.........

 

[quicktach]

Don't think the oil would do it. Sounds fuel related. Check fuel filters. Fresh gas. Check for anything binding or affecting throttle linkage. Doubt it it would be plugs, but check clean regap if need be.

 

[Cady8special]

Thanks for the replies. I have new plugs, new water seperator, but haven't changed the fuel filter. It's probably original, so I should do it anyway. It's just strange. Been running the boat twice a week at least wtih the only change being the fresh oil the other day, some more gas, and some startron. Ran it for 30 minutes or so, and all of a sudden it picks up 300 RPM's at idle? No change at WOT, just idle. I'm going to check the plugs to see if I'm running lean. Question-- is it possible for a carb to be partially clogged at idle speed, but not at wot? Also, I've heard a few guys on here say that their V6 runs only the top 2 cylanders at idle- how can I tell if that's the case with mine? It's a 1999 135HP carbed Bluewater series.


Thanks guys.

 

[Dukedog]

This. It can give ya misery....and not necessary.

First thing I'd check (get rid of) is idle stabilizer. That's after your done and home safe.........

Through it in tha trash. Reset idle timing in tha water, in gear, on tha trailer will work. Set it where you and tha motor are both happy......Usually around 700 rpm.

 

[Cady8special]

I saw a lot of posts about that yesterday. If I remove it, do I need to reset the timing at WOT too? I don't have a timing light handy.

 

[Dukedog]

WOT shouldn't change, Leave tha idle timing just like it is for now.

You do know that all your idle speed setting is done with tha 10/32 idle timing screw and linkages have nothing ta do with it, right?. This is where lotsa folks screw up. They seem ta think idle should be controlled with linkage adjustments on tha V6. They do play their part with settings before speed/timing is set.

Start and turn tha 10/32 screw on tha throttle arm ta set. May need ta add advanct, may need ta retart ta get it where ya want. Just make sure ya don't set it where its low but sounds like its "luggin'" any at all. 700 is a ball park umber for most. This in tha water, in gear ta get where ya want it. You can "practice" on tha hose then do tha final on tha water..............gl

 

[Cady8special]

No Title

Now you've got me worried about the idle. Butterflies are closed, and the screw I'm turning advances the low speed timing, while high speed timing stays the same. The linkages have to be popped off so you can roll the barrell. In this picture I circled 3 screws. The one I adjusted for the idle speed is circled in red. What are the other two screws I circled? Sorry, I didn't get the shop manual yet. Any help would be appreciated.

 

[Cady8special]

Oh and just so you guys know, I'm not still out on the lake.

 

[Dukedog]

Not right. That's tha stop RED. Tha GREEN is idle timing. Tha other 1/4 20 BLUE is tha max cable travel. Arm should be against it at wot.......

You may be ok. Do this after you get rid of tha module.......
Disconnect tha "throttle cable" from tha arm. Look at tha roller on tha carb. you should see a line. Look on tha cam. should see a line. You want these two to line up but tha two parts not touch. Just a tiny gap between tha two. Tha roller can be adjusted on tha carb. Tha cam is adjusted with tha stop (red) make sure tha arm is against tha stop (red) at all times. A bungee works here.
Now put it on tha hose and start it. You change tha idle by turning tha 10/32 (green) .Ya want it ta be around 8 ta 900 rpm on tha hose. Adjust tha cable barrel nut ta fit tha stud on tha arm (still secure against tha stop) where it will put a small amout of pressure pushing against it. When your comfortable with doin' this take it to tha lake/ Put it in tha water in gear and adjust tha idle timin' screw till both you and tha motor are happy. usually 7 ta 8 hundred is good. Just don't get it toooo low even though it will. Ya don't wanna lug it......

 

[Cady8special]

Wow. Can't thank you enugh. I'm the kind of guy who knows enough to get himself in trouble- I really appreciate the help. Now, I disconnected the Idle Stabalizer yesterday. It made zero difference in Idle or WOT RPM's. One thing I noticed after it gave me the trouble the other day was that the tach was bouncing a bit at certain levels under 1000-- not really reving- it was like the tach was picking up noise. That seemed to stop when I disconnected the module. Is that a sign of a bad module? Is there any OHM test on the mod to see if it was bad? Anyway, after I do everything you said above, I'm going to check my WOT timing. From what I've heard, I should be at 23 with the mod disconnected at cranking. Apperently removing the mod makes you lose 2 degrees? Thanks again man.

 

[Dukedog]

Only test I use for tha module is tha "float" test. Results always tha same. They "don't float"....
erratic tack is usually a bad rec/reg. or possible stator. If it does it again swap tha gray wire at tha two reg/rec. There should be one gray not being used. Swap it to that one............