Motor Issue

[merseybluenose]

Out for a trip today and havin some issue with the motor.......start and idle no prob, 2/3 power all good but no top speed, slight cough n splutter, running rough.

Popped the top and had a look and seems to be an issue with oil..........as in doesn't seem to be using much oil and half of the oil reservoir is empty (hopefully shows up in photo, RHS is empty)...is it normal to have half of the reservoir empty? Don't ever remember seeing it this way. Thought maybe an air bubble but have popped lids and hoses and can't seem to get this side to fill?????? :-?:-?
BTW - 40hp Yam 2stroke

82003

[Moonlighter]

Top end issue, sounds like plugs or plug leads could be the issue. Hd someting similar on my yammy 30 many years ago, was a loose plug lead.

Check to ensure plug leads firmly on. If they are, Pull plugs and have a look at each of them as they come out, check that they all look the same, if one is wet could be misfiring on that cyl.

Also check tha fuel tank breathe valve was open. Could be starving fr fuel at high revs if it's closed!

Hope this helps

ML

[merseybluenose]

Thanks Moonlighter, So the oil reservoir is normally like this.....full on one side and empty on the other???

[Moonlighter]

Dunno about the oil thingy. Does it show oil level OK on the beads that are attached to the filler cap? If so, I doubt if it's a problem and is unlikely to be related to what sounds like a misfire issue.

As I suggested, check the leads and the plugs. If they all look good then fuel is probably the issue. If they don't look good, you'll need some expert help.

Is your fuel fresh is the other question. Crap weather lately, means many people not getting out for a long time. Fuel could be stale.

Where are you located? If Brisbane south side, Stones Cnr Marine or Yatala Yamaha have good reputations for their service and would be able to help you.

Cheers

ML

[Muddy Toes]

Maybe have a look on the empty side of the oil bottle.......if there is a senor under the cap or on the bottle somewhere and there is no oil covering the senor this might be telling you it might need to be full.Just a guess.

[Spaniard_King]

Get a compression check to see if you have not caused any damage, this will determine if major action is reqired.