| Author |
Message |
    
Bob Gilbert
New member
Username: wake_me
Post Number: 2
Registered: 05-2007
| | Posted on Monday, July 30, 2007 - 09:09 am: | 
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I bought a 2 year old "like new" 6hp 4 stroke for a dinghy. Problem is at low idle it cuts off. Can anyone tell me where the idle adjustment is? Other things to look for? Replaced plug and fresh gas.
Thanks. |
Graham Lamb
Senior Member
Username: galamb
Post Number: 1260
Registered: 05-2007
| | Posted on Monday, July 30, 2007 - 10:56 pm: |
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Bob, I'll send you an email... |
Tom Kelly
New member
Username: tkelly
Post Number: 1
Registered: 08-2007
| | Posted on Wednesday, August 01, 2007 - 06:01 am: |
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I have the same problem on my 4hp ..... Graham, could you send me that email as well |
Graham Lamb
Senior Member
Username: galamb
Post Number: 1275
Registered: 05-2007
| | Posted on Wednesday, August 01, 2007 - 08:00 am: |
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Ok Tom, on it's way... |
Bill Moyer
Visitor
| | Posted on Monday, August 20, 2007 - 11:54 pm: |
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Please send me the e-mail.I have a 02 6.0 four stroke Merc.I am ready to dump it off the boat.Having fuel problem at idle. ~ Thanks. |
Graham Lamb
Senior Member
Username: galamb
Post Number: 1476
Registered: 05-2007
| | Posted on Tuesday, August 21, 2007 - 07:38 am: |
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Bill, are you simply looking for the carb adjustment notes? |
Jimmy S.
New member
Username: thevalkman
Post Number: 1
Registered: 09-2007
| | Posted on Friday, September 28, 2007 - 04:58 pm: |
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I just picked up a Merc 2004 6hp 4-stroke with a sailboat and I'm having the same issues with the idle. It runs fine with the choke out, but as soon as I try to cut the choke it dies. So I have to run it with the choke on - and the tranny sure doesn't like to shift at 2K RPM! Any help would be appreciated!
Thanks |
sourichanh
New member
Username: nickt951
Post Number: 1
Registered: 01-2008
| | Posted on Wednesday, January 09, 2008 - 10:18 pm: |
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Good day every one.
i just recently bought a 2001 6hp 4 stroke mercury and it also has the same idle problem, the machanic to me to replace the fuel pump. and it didn't do any much good.Graham can you email the solution for that problem as well? and does anyone has a copy of the manuel book to 6hp 4 stroke mercury? thank you so much. |
David Harper
New member
Username: wyobio
Post Number: 1
Registered: 02-2008
| | Posted on Thursday, February 28, 2008 - 03:07 pm: |
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Wow, this seems to be a common problem. I bought a used crestliner with a 2002, 6 hp 4 stroke kicker motor that simply will not idle. I have replaced the plug, run carb cleaner through the gas, and sprayed the carb with cleaner--no change. It will start with the choke on, and run with the throttle turned up, but when you try to idle or troll slowly, it dies.
Could someone tell me what is going on? |
Graham Lamb
Senior Member
Username: galamb
Post Number: 2637
Registered: 05-2007
| | Posted on Thursday, February 28, 2008 - 07:53 pm: |
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David, while 4 stroke motors are nice and quiet, burn less gas than their two stroke counterparts etc, they are considerably more labour intensive when it comes to maintenance and they are way less forgiving of being ignored.
You must run the gas out of them after every use unless they will be used again in the next day or two. If you are going to lay them up for more than two weeks you should also completely empty the carb by draining it. Keep the oil changed at double the recommended interval unless you are running the motor constantly - ditto the plug(s).
When was the valves last adjusted? ever? how about the impeller? lower gear oil?
A 2 stroke will suffer significant neglect from an owner before it becomes a problem - a 4 stroke is not forgiving.
And while I am not trying to single anyone out, and don't know your particular maintenance schedule, it is lack of maintenance that is turning alot of 4 strokes into "junk".
Spraying carb cleaner in the carb is not suffient. The carb probably needs total disassembly, complete cleaning and possible rebuild.
Any single cylinder motor is going to be rough by it's nature, 4 strokes are potentially worse unless tuned perfectly - they only fire on every second stroke, so 50% of the time they are producing "zero" power strokes - if every other stroke is less than it's full potential due to restricted fuel, weakened spark (from an old plug) etc, they will run like crap.... |
David Harper
New member
Username: wyobio
Post Number: 2
Registered: 02-2008
| | Posted on Friday, February 29, 2008 - 10:02 am: |
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Thanks for the info Graham. You confirmed what I had thought--the motor needs to go in to for a tune up and to rebuild the carburator.
I live in Western Wyoming and our lakes here do not thaw until at least mid-May, so the boat does a lot of sitting in the pasture. I always winterize the engines, and the 90 hp 2 stroke has performed well every spring since I have owned the boat with just basic maintainance.
I have several friends with the same or similar 4-stroke motor that are not neglectful, but only take rudimentary care of their motors, and they have had no problems keeping them running smoothly.
Hopefully with clean and rebuilt carburators the motor will perform as well.
Thanks--Dave |
paulmadeira
Visitor
| | Posted on Tuesday, March 04, 2008 - 11:51 am: |
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Hi Bob -
I also have a Mercury 4 stroke that I am about to throw off my boat...Can you also send me your informative email? |
Marvin L Marvin
New member
Username: retired6hpmerc
Post Number: 1
Registered: 04-2008
| | Posted on Thursday, April 17, 2008 - 12:58 pm: |
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Bought 6 hp 4 stroke in 2006 ... went to put it in
this year and had the problems you all are discussing here... Graham .. read many other posts related to Tohatsu (the Tohatsu Guru is the man !!!!) ... did not know about the finicky nature of 4 strokes.. I had to press bulb to keep running... found one post extolling the virtues of SeaFoam (carb / gas additive)... went out to Napa Auto parts this AM .. mixed it 3oz per gal.. I got it spitting and wheezing .. had to keep the choke full out and press on the bulb to keep it running (if one can call it running)... after about 3-5 mins .. IT JUST TOOK OFF !!!!... thanks Tohatsu Guru (and others)... got me a new checklist.. and I am now a SeaFoam fan (also learned the 10%Ethanol gas I am using has some issue with 'water' ???)...
Thanks again all |
Jan Wesseling
Visitor
| | Posted on Thursday, May 01, 2008 - 08:03 am: |
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Dear everyone: Ihave exactly the same problem, can any of you please forward me the e-mail with the solution or suggest me a proper course of action?
Many thanks!
Jan |
David Harper
New member
Username: wyobio
Post Number: 3
Registered: 02-2008
| | Posted on Thursday, May 01, 2008 - 10:06 am: |
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I think you need to take the carb apart and clean it out, then be sure to run the motor dry after each use.
I brought my motor in for a carb cleaning/tune up and it is now running fine. I used it on a 5 day trip to Lake Powell and it idled and ran smoothly. However, I did notice that when trolling at a fairly high speed it would occasionaly sputter. Pumping the bulb would solve the problem...for a while.
I will have to try this SeaFoam stuff!!! |
Graham Lamb
Senior Member
Username: galamb
Post Number: 3080
Registered: 05-2007
| | Posted on Thursday, May 01, 2008 - 10:37 am: |
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Since this is becoming quite a popular topic I have kinda put together a list for all.
I'll start by saying you all really own a small 4 stroke Tohatsu. It may be painted "phantom black" and have Merc stickers on it, but it is a Tohatsu (who also makes the Nissans in this horsepower range). So you have multiple sources for parts - pick the one that is cheapest - they are all identical.
The bottom line is, you own a single cylinder 4 stroke - it's going to idle crappy (in most cases it's not a poor idle, instead just the nature of a single cylinder which is only firing on every second stroke).
But keeping it tuned in peak condition can alleviate some of the perceived roughness. While I have probably missed a thing or two, here's a list you should try and follow:
Replace the spark plug at least once a year, more often if you use the motor exclusively for trolling.
Check the thermostat - in fact check to see that one is there. Merc has a habit of leaving them off small motors in order to save a few bucks. A small motor will "always" idle better with a functioning thermostat, regardless of what some guy at the local dock tells you. Spend the 25 bucks (merc part number 804540) or the tohatsu equavalent (their prices are usually better).
Change the motor oil at twice the recommended rate - ditto the oil filter (some are difficult to find but they are there)
Keep the entire powerhead sprayed down with fogging oil (or similar) to keep moisture off the wiring etc
Always run fuel stablizer in the gas
Run Seafoam (or any other carb cleaning fluid) in the gas as well - all the time
After using the motor disconnect the fuel line and let it run out of gas then completely tighten down the gas vent (on the tank whether remote or on the motor itself).
If laying it up for more than a couple of weeks, remove the carb and fuel filter (if applicable) and drain it completely, also completely drain the gas tank (if located on the motor itself) - basically "winterize it" when you aren't going to use it weekly.
Follow the maintenance schedule in your owners manual - so yes that means either getting a service/maintenance manual and learning how to do it yourself or taking the motor in to have valves/belts etc adjusted back to factory specs
Keep the carb adjusted and inspect it at least annually (especially if it's running like crap). That probably means disassembly and thorough cleaning - replacing needle valves at the first sign of wear.
Sound like alot of work - it is, but that's what you take on when you own a 4 stroke outboard.
If you are still really displeased with the way it runs or not willing to be diligent about all the maintenance, you basically have two choices -
1 - trade it in on a twin cylinder model, they are considerbly smoother; or
2 - get yourself a two stroke - they will withstand significant neglect and still work well for you....
As always, if anyone is in need of a specific set of maintenance instructions, do not hesitate to email directly (click on my name to the left) and I can most likely provide you with what you are after. However, my advice or literature should not be relied upon in place getting yourself a manual or utilizing the services of your local marine dealer.... |
Neal Fitzpatrick
New member
Username: nefskf
Post Number: 1
Registered: 05-2008
| | Posted on Wednesday, May 28, 2008 - 12:06 pm: |
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I have a 2006 Merc 8hp 4 stroke used on my dinghy. Ran fine at end of season and fully winterized. This spring motor will not idle but will run with full choke and some throttle. Suggestions. 1st problem since purchased new.
Thanks |
