Warm up times for 2 strokes

[jaymasta]

I have always gave my outboards (2 strokes) a relativley short warm up period at a slightly raised RPM say 1200-1500rpm depending on the engine, usually 2-3 minutes of that and then usually 2-3 minutes of idling+ along out of the marina or away from the launch. I went out with a friend the other day and he warmed his outboard up for over 10 minutes at about 1500rpm or so and insisted this is necessary to warm up an 2stroke outboard properly. Iam talking about newer strokes with thermostats etc, his particular outboard was a 1999 100hp yamaha oil injected. Just wondering what you all do and what your thoughs on it are?

 

[coolguy147]

Re: Warm up times for 2 strokes

well i got a 1958 outboard and it usually takes 2-3 minutes too. it also has a t stat. when i see water misting and squirting out the back then i know its warm up but your choice.

 

[Silvertip]

Re: Warm up times for 2 strokes

A couple of minutes is all that's required, and not at 1500 RPM. 1000 RPM is all that's needed. That does not mean pull away from the dock and hammer down. Another minute or two at part throttle raises combustion temperatures quickly so it is then ok to hit it. You don't have to wait for the thermostat to open either. The minute you hammer down the poppet valve opens anyway dumping a bunch of cold water through the motor.

 

[steelespike]

Re: Warm up times for 2 strokes

I don't warm the motor except to be sure it is working right.Wheather 20 degrees or 100 degrees I start the motor untie and procede.
I don't blast it ever when still warming and seldom run wot anyway.
I have 87 and 88 Evinrude 50s with no issues related to engine operating procedure.Have been boating 60 years.Probably a dozen motors over the years.I feel excessive idling warmup puts unneccessary, unnatural wear on the motor because it prolongs warm up.
I do the same with my cars.If I was a block from the freeway I would do a bit of a warm up and probably wouldn't run at 70 plus for a few minutes.
I certainly wouldn't ream it out until fully warmed.

 

[pecheux]

Re: Warm up times for 2 strokes

IMO and in practice ... I feel a few minutes is all that's necessary to get the pistons oiled up. In cold weather I would multiply by 2 ... lol

 

[Woodnaut]

Re: Warm up times for 2 strokes

Just asking a question here guys, but isn't it more the concern that it's an aluminum block rather than a 2 stroke? (Coefficient of expansion is higher in aluminum and possibly more scuffing due to loose tolerances at lower temperatures... Just a few thoughts.)

I generally let my machine warm up a good 5 minutes before I get on it. These darn outboards are expensive these days.

 

[coolguy147]

Re: Warm up times for 2 strokes

well i dont wait there forever.....

 

[Simoniz]

Re: Warm up times for 2 strokes

Always best to warm up a motor with a bit of load on it than at idle.

I normally untie the boat, then holding it to the dock with 1 rope, start the engine, throw the rope, put it into gear and motor off at no wake speed. I wouldnt put a lot of power on it though until the temperature gauge had reached the normal mark (or 5 minutes if no gauge).

 

[Silvertip]

Re: Warm up times for 2 strokes

Hammer down a cold engine and you run the risk of cold seizing which is caused by the pistons heating up faster than the surrounding engine block. Combusion temperatures are very high in relation to the water jacket so pistons expand quicker than the block causing the seizure (or scuffing as was pointed out earlier). Neither are good for the engine. If you are simply the impatient type, start it up, push off and then then just putt away for a minute or so to allow half a chance for things to stabilize.

 

[robert graham]

Re: Warm up times for 2 strokes

I crank motor to pull off trailer, then by the time my passengers park car and get back to dock, get in, find a seat, etc.,etc. there's plenty of time for motor warmup. Just good common sense probably will work here. Good Luck!

 

[coolguy147]

Re: Warm up times for 2 strokes

ya same here 2-3 minutes is i need to open the t stat but thats about the time im ready to leave. put gas in boat hook up battery then warm up. untie from boat lift. turn motor off push boat through weeds then restart and go on my maiden voyage