Two stroke conumdrum

[Ballistix]

Just "serviced" my new two stroke 4hp and took it down the river. It starts perfectly but seems to be missing in some way at low revs a bit of a tweak on the throttle and it goes "smooth" again but after a few seconds appears to operate in a rough way again...any ideas? or should I just get it tuned?

T

 

[yankee1]

I would check spark plug; fuel quality particularly if it has been sitting around, then carb settings...

 

[Kawasaki]

'New' two stroke?
What's the model Sir?

 

[SpottyDog5]

how old is the fuel? it dies....

 

[SpottyDog5]

but then you know that, too many beers for me tonight.

 

[Ballistix]

Hi sorry, new to me, its a 2001 merc 4hp 2 stroke. it has brand new mixed fuel from yesterday because i wasnt sure what was in there and a new spark plug. I might just drop it off to the little outboard place next to my new marina today.

 

[SpottyDog5]

I would strip the carb down, probably a bit gummed up?
Very easy to do when sat in the Lulworth, if you do want to someone to look at it, I can recommend Bursledon Outboards, just by the bridge at Swanwick

 

[misterg]

[ QUOTE ]
Just "serviced" my new two stroke 4hp and took it down the river. It starts perfectly but seems to be missing in some way at low revs a bit of a tweak on the throttle and it goes "smooth" again but after a few seconds appears to operate in a rough way again...any ideas? or should I just get it tuned?

T

[/ QUOTE ]

Probably either a bit of plug fouling, or '4 stroking' at idle (due to the mixture being a bit rich)...

Ideas:

1) Make sure it's well warmed up, and the choke is all the way off

2) Give it a good blast (30 mins+ under load) to clear it out (do watch for overheating, though in case it's something more serious).

3) Try a different plug

4) If you used dodgy 2 stroke oil, or didn't mix it reasonably accurately, start again /forums/images/graemlins/smile.gif

5) Does petrol start dripping from the carb if you leave it idling? If so, the float valve isn't sealing properly - remove dirt & try again.

6) If no better, make the idle mixture a tiny bit weaker, but not so weak that the engine hesitates when you snap the throttle open from idle. (Sorry, don't know whether you have a fuel screw, or an air screw on this - if fuel, screw it in ~1/8 turn, if air, screw it out about the same & try again.)

7) If 6 didn't work, put things back as they were.

8) No 2 stroke likes idling for any length of time - learn to live with it?

9) It could be electrical (but I doubt it), in which case you're on your own /forums/images/graemlins/smile.gif

10) If K. suggests anything else, do that first /forums/images/graemlins/grin.gif


Andy

 

[yankee1]

geez...forget Bursledon Outboards...just drop it off with misterg!!

 

[Ballistix]

Heh thanks guys, yeah I met Steve and Dan there a few days ago they've provided me with some parts they seem bloody good I do say...was going to drop it there due to time but thanks for the tips!

T