RPM general question.....

[eddie haskell]

I decarbed my 92 suzuki DT85, and it seems to really idle better. A bit of background, the motor is new to me. The PO was running a 50/1 mix and said he disconnect the oil injection, which he did not, it was just full of sludge, and set off the flow switch alarm....
Anyway, I cleaned up everything, all the plumbing, etc, oils great now.

My question is, the directions said to shoot the whole wad into the carbs, wait 30 minutes, then run half throttle for 5 minutes.....
I don't like running up a motor with RPM's if it hasn't no load on it.
I know the motor can go above 5 G, but wouldn't that be bad for it like that?

I did two applications, over two days, with just a half dose each time. The first one really smoked after I fired her back up, the second time, not bad at all.....

Thanks

 

[ondarvr]

I have no idea which product you used, but typically they mean in gear on the water, not on a hose.

 

[eddie haskell]

On the water huh.....not sure I would dig that. I recall reading others who did this procedure to "warn" the neighbors so they wouldn't think the house is burning down :joyous:

 

[ondarvr]

I have never had a motor smoke or do anything odd during a decarb. I have had some white smoke, but that's it.

You never rev an outboard with no load on it, it can get into runaway mode and you can't shut it off.

 

[99yam40]

There are different chemicals and procedures to decarb
What did you use and how did you do it?

I have used Seafoam before in the heavy dose and it smoked very bad until the carbon was removed

The C40 Yamaha motor had its jets drilled out by someone and run that way for how knows how long. (too rich)
once I replaced the jets back to the factory size, I warmed up in drive way and shot it into all 3 carbs until it choked it down.
pulled the plugs and shot more into the cylinders.
let it sit over night took to ramp added a can of sea foam to a gal of premix gas/oil then ran it for 15 minuets, shut off and fished for awhile and fired back up and ran again. repeated til all of fuel mix was used up.
the smoke went away after a few runs
had to catch the black goo dripping out of the exhaust in a drain pan after parking back in driveway

 

[ondarvr]

I have normally used Seafoam, but have used others. Seafoam has never produced any dark smoke, only a white smoke while it was being burned. And I used it in several different ways.

 

[99yam40]

I do not remember anyone saying it was dark smoke, just lots of it at first

 

[eddie haskell]

Got the stuff from Brown's Marina:

1

CRC06121

Marine Engine Tune Up & Decarbonizer

$9.78

Yeah, I never gave it much throttle, and only sprayed enough that I thought was about right. I did it twice, a day apart.
I got white smoke too, not blue or black or rainbow :lol:

Anyway, thanks guys, my question was answered about revving the engine.
Even tho I often see guys giving their engines He LL at the ramp sometimes, I always thought it was dumb and did nothing to enhance the outboards performance.

I still have not put the boat in the water, however, I is close!