anyone been able to get their 3cyl 2stroke to actually idle good?

[Aviator04]

If so, what did you do? My 2006 90 elpto idles like something from the 70's. I know they're not the smoothest motors out there, but I've read some people swear they were able to smooth it out by adjusting carbs, using synthetic oil etc.. Ive drained my oil & filled my oil with Amsoil Hp synthetic. Low speed screws all 1.5 turns out. So far, no noticeable change. Compression good.. Anyone able to improve it or did you just learn to live with a lousy idle?

 

[jimmbo]

Well, it is a 2 stroke Looper, and loopers tend to be a bit lumpier at idle than Crossflows. Setting the Idle mixture is not just backing the screws out to some value, they do need to be adjusted while running under load. What is you r current idle RPM, and what is the recommended value?

 

[Faztbullet]

Adjust in the water, in gear ,engine level to get it the smooth out a bit.

 

[Texasmark]

My 2002 90 ELPTO idled just fine. I used clean 87 Ethanol, Pennzoil Premium semi-syn TC-W III oil, kept Sea Foam in the fuel (1 oz per gallon) and kept fresh plugs in the engine. Per the manual, idle was to be set (knurled idle screw on throttle arm which changed timing advance to obtain correct reading) at 675 +/- 50 rpm....idea was fast enough to keep the engine running but slow enough to ensure clean shifting with minimum gear crunching.........as Faz said, in the water, in F gear, boat in motion....like do it while you are in the harbor's no wake zone.

High speed jets are fixed. Low speed jets are stated to be set for minimum fuel value that will allow the engine to take the throttle when you firewall it in the hole shot....course lots of variables here and one is your trim position. Your best bet (opinion) is to have a usual trim position for your hole shots and use that position for your adjustment. Hull shape, boat load and distribution are the other major players assuming the hull isn't algae coated, or full of Barnacles.....assuming the engine is in good tune.

 

[Aviator04]

thanks guys! Will try that. Would i be able to put this in gear in a test tank to make adjustments or will i just shoot water all over the place?(lake is currently frozen).. My current idle is about 1000 rpm's (according to my tach). What I've noticed though, is when i cold start it, the rpm's are very low and the engine is smooth & quiet but as it warms up, the idle bumps up too.. Is that normal? Texasmark: out of curiosity, do you find your 90 to be any louder than other 2 strokes of similar hp?

 

[Texasmark]

thanks guys! Will try that. Would i be able to put this in gear in a test tank to make adjustments or will i just shoot water all over the place?(lake is currently frozen).. My current idle is about 1000 rpm's (according to my tach). What I've noticed though, is when i cold start it, the rpm's are very low and the engine is smooth & quiet but as it warms up, the idle bumps up too.. Is that normal? Texasmark: out of curiosity, do you find your 90 to be any louder than other 2 strokes of similar hp?

You might tweak it enough to keep running while you shifted with minimum crunching of gears.....then when you get out where you can do it properly, do that.....if you have a hose replacing the water you blow out of the barrel....if using a 55 gallon drum.

On noise, actually, after having run Mercs of the '60's the engine was very quiet as is my current 2002 115 of the same design. Running the top end of the recommended RPM band and such, hard to say that they are whisper quiet, more like comfortably quiet without ear protection with conversing at a louder than normal level to be heard. Only comparison I have is a 1972 Johnson 125 I bought in that year and I would say the noise levels were similar....recollecting.....course back in the day when Mercs were screaming.....and screaming by them, OMC prided themselves on their "quiet" engine designs. On that subject, I never could run with a Merc 125 of the day.....always got caught in their prop-wash on similar rigs. Course if you are talking at that speed, you need to keep your mouth closed.....bug ingestion probability....Grin......sorry I couldn't help it. Coffee is good this morning.

 

[Aviator04]

thanks for the tips guys... any ideas how the 90 would do on an 17.5' bowrider? I know it won't be a speed demon but really hoping its adequate. Thats the issue when buying off season when the lake is frozen

 

[hardwater fisherman]

I think the general rule as at least 75 percent of max hp rating...

 

[jimmbo]

Depending on the Hull shape, condition, what kind of load... between 28 - 33mph

 

[Texasmark]

I don't know about a undefined bow rider, but on a Tin Lizzie, Bass Boat of that length, with a 13 X 24XL SS Ballistic, at 56-5800 rpm will hug 50, not kiss it, GPS hug it on a cool day....my Avatar.

 

[TrybalRage]

thanks for the tips guys... any ideas how the 90 would do on an 17.5' bowrider? I know it won't be a speed demon but really hoping its adequate. Thats the issue when buying off season when the lake is frozen

My 2001 90 ELPTO gets around 30mph (GPS speed) on my 17' center console. I think I could do better with a better prop.

To answer your original question, mine idled like crap until I rebuilt the carbs and replaced the oil check valve. I believe it was allowing too much oil to mix with the fuel. I used to have to keep the RPM's up higher than I wanted while crabbing to avoid stalls, now it idles much smoother (for a 2 stroke) and a whole lot less smoke.