Merc 200 v6 sneeze when blipping throttle - video enclosed.

[Superjetjim]

New engine (to me) it's a year 2000 v6 Mariner/Merc carb.

Started it for the first time today, compression equal on all pots. Idles ok, but when I blip the throttle via the fast idle leaver it sneezes out of the lower left air intake as the revs drop back down - see attached video.

http://www.youtube.com/watch?v=fUmUiazAZ2Q&feature=youtube_gdata_player

Not sure what could be causing this but I did notice the timing advance arm (looks like it goes up to the fly wheel) is a bit slow to move/sticking - would this cause it? Just seems wierd that it only comes out of the lower air intake and not all the others. I'll pull the carbs and clean tomorrow if required - don't want to lean seize it if this is being caused by a gummed up carb?

Thanks for any help!

Jim

 

[Superjetjim]

Re: Merc 200 v6 sneeze when blipping throttle - video enclosed.

Can anyone help please? Perhaps one for Fazbullet?!?

Will pull/strip/clean the carbs today if required?

 

[sxmerc]

Re: Merc 200 v6 sneeze when blipping throttle - video enclosed.

Could very well be a gummed carb. Why not do the carbs and start off fresh for safety sake, and piece of mind. Could also be a timing issue, but I think there is the possibility of a damaged or missing reed. While you got the carbs off, take a look in with a flash light, and check to make sure all the reeds are there, undamaged, and that they are all completely closed. My two cents...

 

[Superjetjim]

Re: Merc 200 v6 sneeze when blipping throttle - video enclosed.

Could very well be a gummed carb. Why not do the carbs and start off fresh for safety sake, and piece of mind. Could also be a timing issue, but I think there is the possibility of a damaged or missing reed. While you got the carbs off, take a look in with a flash light, and check to make sure all the reeds are there, undamaged, and that they are all completely closed. My two cents...

Thanks will do, can you see up the reed cages with a torch once you have the carbs off or do I need to pull the cages as well?

Cheers

Jim

 

[sxmerc]

Re: Merc 200 v6 sneeze when blipping throttle - video enclosed.

I like to have the reed cages in my hand for thorough examination, but a broken or chipped reed should be plainly visible with just a flashlight.

 

[Superjetjim]

Re: Merc 200 v6 sneeze when blipping throttle - video enclosed.

Right, carbs stripped, cleaned and rebuilt last night, no obvious blockage or varnish in them. Did a detailed clean with carb sprays and tooth brush on all the ports.

Looks like I need to pull the reed cage next..

 

[Faztbullet]

Re: Merc 200 v6 sneeze when blipping throttle - video enclosed.

From what I seen and heard its ok as a defective reed will cause idling problems and you will hear it spitting back into carb throat. That looks more like a crankcase misfire and from the looks its from the oil pressure fitting to oil tank and not from air cover. This can be caused by lack of backpressure,loose connections, split/leaking bleed line.

 

[Superjetjim]

Re: Merc 200 v6 sneeze when blipping throttle - video enclosed.

Faz, you might well be onto something - I bypassed the oil injection system in favour of premix the other day. The motor didnt come with an external main oil tank just the little one on the top. I disconnected the fuel line and directly connected it to the fuel pump, unplugged the small oil header tank from the oil pump and blocked it off, then disconnected the oil level float sensor from the header tank. I guess I have a plug somewhere that provideds pressure to the main oil tank (that isn't blocked off?)

Any idea where this oil pressure fitting could be located?

I am collecting the oil block off plug this weekend - what else should I bung or block over the above items?

Cheers

James

PS - Are you some sort of Merc Supertech or something? - Your ALWAYS right

 

[Superjetjim]

Re: Merc 200 v6 sneeze when blipping throttle - video enclosed.

From what I seen and heard its ok as a defective reed will cause idling problems and you will hear it spitting back into carb throat. That looks more like a crankcase misfire and from the looks its from the oil pressure fitting to oil tank and not from air cover. This can be caused by lack of backpressure,loose connections, split/leaking bleed line.

Faztbullet,

You were correct (again) - it was an unplugged injection hose.

Tried to send you a PM/beer token but your inbox is full.

Cheers

Jim