[bakdraft]

My new SX18 has had engine issues from new... not major... just the idle.

What happened would be that after any form of run, when you came to a stop, the engine would idle OK for about 15 seconds... then would sound like it was going to die. You would then run to rev it a bit to keep it going.

Once ( at only 6 hours old ) on arival back at the shore after a trip, it idled for about 10 seconds... then cut out. It then point blank refused to start. OK I thought, it comming out now anyway, I will try again when I get home. 1 hour later it still refused to start... infact it turned over fine, but made no effort. Oh! I thought.. it looks serious.

Two days later, I went out to try to work out what was wrong... but it started first turn of the key!

Now who wants a boat that cuts out and wont start for 2 days.

Back to a specialist mercury dealer it went.

Initially they found nothing wrong, but when they removed the carb, they found that the airbox was split in 3 places!

Not only that, the air filter is held in place by 4 studs, one of which was broken off AND had fallen inside the carb!

Boy was I sort of glad to hear that. Not only was it the likely cause of the fault, it also meant it was a warranty issue and non chargeable as opposed to dirty fuel et al, which is chargeable.

I get the boat back next week, so I am hoping that is the end of the problem.

The dealer thinks the issue was an assembly / installation problem.

So if you have a new boat with idle problems....

I will let you know how I get on when it back in the water next week.

Dave

[il_Mio]

Hi Dave,

just gave you a pm prior to reading this post.... and yes I had an Idle run issue, exactly like you mention. I run for 4,5 hour with the boat without issue, but when slowing down near Idle it hesitated, and in idle it dropped of completely. So I had to do dangerous stuff to get the boat back boxed again near the slipway (as you need to go through idle in order to reverse to slow down - read brake )...

The shop told me to adjust the idle run at home with the hose connected, which I did and now it idles at 850 RPM, but I did not yet take it out for a real testrun since.

With this stuff you posted, I don't dare to do another real testrun, I would prefer taking it straight to the dealer and have it inspected ( but is a 3 hours drive !).
Is there something I can inspect visually easily myselve first to notice it is the same issue as you had ?

Kind regards,

Johan

[bakdraft]

Originally Posted by il_Mio

Is there something I can inspect visually easily myselve first to notice it is the same issue as you had ?

Kind regards,

Johan

When I pick the boat up from the dealer next weekend I will get him to give me the full explanation and get him to show me where etc and let you know. If he still has the old parts I will photo them.

It is definitely not what you want happening to you out on the open sea as in my case

[WetWilly]

Hi bakdraft,

Glad the problem was discovered before the stud found it's way into the engine. Iooking on the bright side, this is now documented so should you have any later issues with the engine, they'll probably give you the white glove treatment!

WetWilly

[bakdraft]

Originally Posted by bakdraft

When I pick the boat up from the dealer next weekend I will get him to give me the full explanation and get him to show me where etc and let you know. If he still has the old parts I will photo them.

It is definitely not what you want happening to you out on the open sea as in my case

OK, I got the boat back yesterday, but have not had time to run her yet.

Attached are two photos detailing the fault.

The issue they found was that the air filter (flame arrestor) had been tightened up too much from new. This then caused the complete assembly to break up. It is only made of plastic.

Inside there are 3 plastic studs that keep the filter centered. Two of which had snapped off completely, one of which was loose inside the carb.

The base of the same airbox was split up completely and cracked apart.

The dealer replaced the complete unit, but it now means the engine data, which is normally on the arrestor lid is now missing as it is a sticker on the old broken unit.

In the case of il_mio, I would take the unit off, ( 1 nut ) and look for cracks. BUT NOTE - although the unit is shown here in two pieces, it seems to me originally it was one welded together unit at the studs. This would imply it does not come apart but is replaced as one complete unit. I can't be sure though. So take it of and if it come apart all well and good, BUT do not force it apart. instead, look for cracks at the bottom, and around the point where the nut fastens down.

I cannot get the boat out for two weeks to check if the tickover is fine, but I will keep you posted.

Dave

[il_Mio]

Originally Posted by bakdraft

OK, I got the boat back yesterday, but have not had time to run her yet.

Attached are two photos detailing the fault.

The issue they found was that the air filter (flame arrestor) had been tightened up too much from new. This then caused the complete assembly to break up. It is only made of plastic.

Inside there are 3 plastic studs that keep the filter centered. Two of which had snapped off completely, one of which was loose inside the carb.

The base of the same airbox was split up completely and cracked apart.

The dealer replaced the complete unit, but it now means the engine data, which is normally on the arrestor lid is now missing as it is a sticker on the old broken unit.

In the case of il_mio, I would take the unit off, ( 1 nut ) and look for cracks. BUT NOTE - although the unit is shown here in two pieces, it seems to me originally it was one welded together unit at the studs. This would imply it does not come apart but is replaced as one complete unit. I can't be sure though. So take it of and if it come apart all well and good, BUT do not force it apart. instead, look for cracks at the bottom, and around the point where the nut fastens down.

I cannot get the boat out for two weeks to check if the tickover is fine, but I will keep you posted.

Dave

Thanks Dave,

sorry for the late reply, just got home last night from Aïgues-mortes in South of France after a 12h drive. I will have a look today, looks straight forward to inspect prior to a run.

Kind regards,

Johan

[bakdraft]

Well, had her back in the sea today for 1.5 hours.

What a difference.... I was amazed at the improvement. The engine sounded great.... smooth and quiet. Tick over was good straight from start up, and after any period of running was great for long periods of tickover.

The only slight issue was that after stopping for about 15 mins, it restarted Ok, but tick over was a bit low, and I had to manually increase it a bit with the throttle lever, but once under way it was back to normal.

The only thing I can think was that those bits of plastic that had fallen inside the carb, must have kept it on choke for the full first 6 hours of running.

Still she is great now.