update on 75 honda 2004 four stroke

D

duckman

New member
After taking in the outboard because of a stalling problem I was informed that the four carbs were cleaned...but when the top plug was pulled it had no affect on the rpm. The plug was firing. The mechanic was not happy with this, was not sure why and suggested taking it out and running it with some Yamaha ring cleaner. Except for a slight, very slight hestation at 1800 rpm the motor ran well full throttle getting up to 5100 rpm in choppy water.

My question is... would I even get to 5100 rpm if the top cylinder did not appear to be contributing when at 2000 rpm in drive with the earmuffs on?
Full power range according manual is 5000-6000 rpm.

The mechanic is certified for Honda and comes highly recommended by two state agencies...so I have confidence in him. He says openly that Honda carbs (four stroke) can be real beasts and sees way too many problems with them.

Thanks...I would appreciate any insight I can get.

Frank
 
Just went through this with my Yamaha, I had two cylinders not working, but the plugs were firing. I was getting up to about 5000 rpm too (should be closer to 6000 at WOT), but with virtually no power.

The needle valve seat in the carb was damaged by the ethanol, and it will prevent any fuel (or too little) from entering the cylinder and igniting. So while everything is working, there is no fuel to burn in those cylinders. The air mixture orifaces can also be clogged with the ethanol gel or varnish and they are next to impossible to clean completely. You can soak the carb after it is taken apart and use compressed air to try and blow the softened gunk out, but no guarentee.

The labor charge for cleaning all four of my carbs (with no guarentee it would work) was within $1200 of trading the old carbed engine in and going with a new EFI, and replacing the carbs which would definitely fix the issue was only within $500, so I upgraded to the EFI engine and I won't have those issues anymore.
 
It sounds like the plug on that cylinder is firing, but not producing any power.

Did the mechanic do a compression test? Or a leak-down test?

Those two tests should show if the rings and valves are working properly or not.
 
Hello,
I would have him do a compression test on all four cylinders. Carburetors are a problem if gas sits in them a long time and gums up. If the boat is not going to be used for a month or more the recommended procedure would be to remove the gas supply line from the motor and run them dry and then remove the float bowl drain screws drain and reinstall the screws.
If the cylinder is not getting any gas to fire removing spark would not change much.
Make sure you have good fresh gas before reconnecting the gas supply. Their are a number of gas additives that should be used regularly to prevent carbon build up etc. Marine Stabil and a host of others to prevent gas from turning bad or having phase separation which is the ethanol separating from the gasoline during storage. This separation sometimes results in the engine running on straight alchohol causing catastrophic failure such as holes in pistons I'm sure others can chime in about what works for them.
Good Luck! D.D.
 
We have seen a ton of problems with carbs ruined by bad gas, and our recomendation is to replace insted of trying to clean the carb, because we haven't had good success with cleaning them (runability problems continue after servicing carbs).
 
For those of you who are concerned with the problems of alcohol in fuel here's good news: The ethanol lobby (yes, there is such a thing,) has hired a retired general to lobby for increasing the maximum allowable amount of ethanol in gas to 15%, from 10%. This is from THE LOG, the SoCal weekly sailing paper. The general says that will add 130,000 more jobs and reduce our dependence on imported oil. How can you refuse that? Note that this would be at the national level, not just California.

The NMMA indicates that their motors cannot handle that amount of alcohol. That statement never stopped a politician before, and it hasn't now. California is trying to require that gasoline, whatever that means, has less carbon in it. I thought that carbon was part of the chemical reaction that produced the heat for power. Thus, I thought, less carbon means we burn more fuel to make the same power. On that basis, the refiners can charge us more per gallon to make the fuel, AND we have to burn more. The motor manufactures now get to sell new motors that can run on more ethanol. Everybody wins!

So wait awhile before you trade in those old motors that can't handle alcohol for those which can only handle 10%. If the good general and the California Smog board get their way, we'll be running straight ethanol.

Yes, I'm not truly happy!!!!!!!!!!!

Boris
 
Hey, I've got one of those motors. Just hit 6.7 hours on the meter. I really like it. Wonder if I should get it listed on Craigs' List before everyone figures out it is really obsolete. This whole thing is getting outrageously out of hand. Create 130,000 new jobs and a large percentage of people with boats, bikes, ATV's, UTV's, lawnmowers, etc. that they cannot afford to relace. What does that do for stimulating our economy? Sorry, I just really needed to RELEASE for a number of reasons. I promise my next post will be more up-beat!
 
Duckman:

The carb'ed Honda gets incredibly high mileage at or near idle speed (reportedly better than the injected version), and does so by running at a very lean, well mixed, ratio of fuel to air. It's possible to have a total or even partial blockage in the idle fuel supply to one carb, and still have that cylinder run fairly well at higher speeds. Before doing anything else, I'd pull the plugs, and a visual inspection should tell whether fuel is being burned in the questioned cylinder. I'd also have the mechanic attempt to balance the carbs, and see if the one that is not firing at idle is just out of adjustment.

The hesitation is another issue, which can be discussed further once you're firing on all 4.

Let us know what you figure out.
 
journey on":b5vdlt3d said:
For those of you who are concerned with the problems of alcohol in fuel here's good news: The ethanol lobby (yes, there is such a thing,) has hired a retired general to lobby for increasing the maximum allowable amount of ethanol in gas to 15%, from 10%. This is from THE LOG, the SoCal weekly sailing paper. The general says that will add 130,000 more jobs and reduce our dependence on imported oil. How can you refuse that? Note that this would be at the national level, not just California.

The NMMA indicates that their motors cannot handle that amount of alcohol. That statement never stopped a politician before, and it hasn't now. California is trying to require that gasoline, whatever that means, has less carbon in it. I thought that carbon was part of the chemical reaction that produced the heat for power. Thus, I thought, less carbon means we burn more fuel to make the same power. On that basis, the refiners can charge us more per gallon to make the fuel, AND we have to burn more. The motor manufactures now get to sell new motors that can run on more ethanol. Everybody wins!

So wait awhile before you trade in those old motors that can't handle alcohol for those which can only handle 10%. If the good general and the California Smog board get their way, we'll be running straight ethanol.

Yes, I'm not truly happy!!!!!!!!!!!

Boris
Click to expand...

If it goes thru in Cal, it's just a matter of time before the WA. State socialists adopt it too. Ah, the left(ist) coast. :roll:
 
Carburetors are a problem if gas sits in them a long time and gums up. If the boat is not going to be used for a month or more the recommended procedure would be to remove the gas supply line from the motor and run them dry and then remove the float bowl drain screws drain and reinstall the screws.
Click to expand...

I was using that approach, and in conversation with a 'certified' Honda mechanic he recommended that I use Stabil in the gas and just shut the engine off without running it dry. For someone who's never seen the inside of a carburetor it sounded reasonable, but I'd like to hear what others think.

Tom
 
journey on":peju5d2e said:
For those of you who are concerned with the problems of alcohol in fuel here's good news: The ethanol lobby (yes, there is such a thing,) has hired a retired general to lobby for increasing the maximum allowable amount of ethanol in gas to 15%, from 10%. This is from THE LOG, the SoCal weekly sailing paper. The general says that will add 130,000 more jobs and reduce our dependence on imported oil. How can you refuse that? Note that this would be at the national level, not just California.

The NMMA indicates that their motors cannot handle that amount of alcohol. That statement never stopped a politician before, and it hasn't now. California is trying to require that gasoline, whatever that means, has less carbon in it. I thought that carbon was part of the chemical reaction that produced the heat for power. Thus, I thought, less carbon means we burn more fuel to make the same power. On that basis, the refiners can charge us more per gallon to make the fuel, AND we have to burn more. The motor manufactures now get to sell new motors that can run on more ethanol. Everybody wins!

So wait awhile before you trade in those old motors that can't handle alcohol for those which can only handle 10%. If the good general and the California Smog board get their way, we'll be running straight ethanol.

Yes, I'm not truly happy!!!!!!!!!!!

Boris
Click to expand...

Be sure to go here and send your letter!! Be sure to tell everybody to do the same.
http://capwiz.com/nmma/issues/alert/?al ... ake+Action
 
My Honda mechanic said the same thing: dose with Stabil, then store with gas in the carbs. I've done it both ways, just for the heck of it, and am more pleased with the results when the Stabil is in, and the carbs full.

This last winter, I stored the boat with one tank bone dry, and 5 gal. of 10% ethanol gas in the other, dosed with the "storeage" concentration of Stabil Marine (the blue stuff, which is a better buy, and newer formulation than the pink). I fogged the carbs before storage.

The motor fired right up when I tried it during the winter, and again, early this spring. The 5 gal. of gas that had been stored all winter burned out clean this last weekend. I'd filled the empty tank with fresh gas, and the motor burned that without incident, after being switched over when the 5 gal. had burned. No problem with water in either tank, except for whatever small amount might be parked in the bottom of the fuel/water separator.

So, my current procedure is to add Stabil Marine EVERY time I take on gas, even if I'm going to burn it right away (been adding stabilizer regularly for some time, and am very pleased with the results), and double dose for long-term storage, without draining the carbs.

Let us know what works for you.
 
I would like to thank everyone for their suggestions carb issue on my 75 horse 2004 honda fourstroke. A real learning experience for an old two stroke boater.

I called directly to Honda headquarters and got a service/tech rep. I ask him how best to deal with the four stroke carb sensitivity. He acknowledged what my mechanic and several of you said...the carbs by design are touchy to fuel and thus cleaning issues. He asked me if I had the four carbs acid bath cleaned or with"ultra sounding", (never heard of that one). I asked about ethanal gas and if Honda still recommends it...he said yes, but only 10% alcohol and no more.

OK...so I call the mechanic who cleaned the carbs and told him that I ran it smoothly up to 5100 RPM except for a slight hesitation at 1100 RPM. The Honda rep said I should have reached 5600 or so. I ask him how he cleaned the carbs and he said with a carb cleaner bath...that he does'nt do acid bath and never heard of ultra sound cleaning...and actually was a little irked that Honda said such a thing. He still thinks I should run it hard for an hour in the water when that dam wind stops blowing. For kicks I called a regional Honda dealer who only heard of ultra sounding a carb for use in Honda autos...he also said a hesitation at 1100 RPM is fairly common in that motor.

Well enough said...again thanks for sharing you experiences on this issue. I hope I can get the best performance out of my Honda so I can enjoy some long trips this summer.

Frank-owner of 2004 C-dory 22 footer
 
Thanks Denny,

I wonder if Honda dealers/service are all on the same page on carb cleaning. All three dealers I called don't have the knowledge or equipment to do the U-S cleaning. While doing wildlife enforcement work around the region with a variety of boats ...I never heard the term before while in repair shops. But thats been awhile now, back in my 2-stroke life.

Frank
 
Hmm, that sounds like you asked the wrong person.

From Wikipedia:
"Industrial ultrasonic cleaners are used in the automotive, sporting, printing, marine, medical, pharmaceutical, electroplating, disk drive components, engineering and weapons industries."

We certainly used them for aerospace, and I thought that they were fairly common. Heck, Harbour Freight even has (or had) one. Keep asking until someone can give you a reasonable answer. They do a great job of cleaning small parts, holes without caustic solutions. Which is why Honda (or any EFI outboard) dealer shoud be familiar with them.

Boris
 
Used by my VW engine guy to clean carbs, fuel pumps etc. Weber and Delorto carbs are very complex and are widely used in the air cooled VW hobby.

When winterizing my collector VW I fill the tank with new fuel & Stabil, run the engine for at least 10 minutes, change oil, plug in the charger and cover it up. Never had a problem with starting it up in 4 yrs.
 
Back
Top