2008 Glastron GT185 Questions...

Hey everyone.

I got a few questions. I am fairly new to the boating world. I am used to working on snowmobiles and have been trying to use some of those skills to fix a few things on the boat. If anyone knows where I can find a service manual or part diagrams for the boat that would go a long way for me.

So here is the problem. No matter how warm it is when I go to take off it seems to stumble. Sounds like a fuel problem. RPM's will go up then the boat will sound like it stalled (Sometimes it does) then it will catch itself again and be good to go until I come to a stop and take off again. It will also have a hard time starting and does not like to idle on its own. Idles fine if I put it in neutral and move the throttle until I get to the first "click".

I feel like it could be idling too low? How to I adjust the idle/what should it idle at?

I don't even know where the carburetor is in this boat to try cleaning it. Its the 3.0L Merc.

With snowmobiles if I experience these problems changing the spark plugs will fix it 99% of the time. Is it the same with boats?

Thanks for any help!

Re: 2008 Glastron GT185 Questions...

Could be a few different things...

number 1) Bad fuel... the stupid ethanol they are putting in fuel these days is reaping havoc on our marine engines and seals. There are multiple law suits and what not going after the government about this and even more so trying to stop them from upping it from 10% --> 15%. Have you owned the boat since new and did you store it with fuel stabilizer in the tank? Also with every fill up to battle the stupid ethanol they are putting in the fuel, adding the fuel stabilizer seems to be cutting back on these fuel problems.

2) According to my 10' manual spark plugs shouldn't need to be changed till 2 years or 150 hours. Just like any tune up, fresh plugs will help but if your running bad fuel they will become fowled again.

3) The Carburetor is located under the flame arrestor. On your motor its under the decal which says 3.0L and element which looks like an airfilter. Here is my 4.3L, mine is located under the black plastic bonnet with the 4.3L GL lettering.



Trying working out the fuel and spark plugs first before digging deeper to adjusting an idle on a carb motor. Hope this helps.

Re: 2008 Glastron GT185 Questions...

Thanks!

I did own it since new and i have experienced these problems since new but it was to a much lesser degree.

I did consider the fuel but it does it even with 91 octane with very little to no ethanol in it. It was always stored with stabilizer. I will try running with seafoam to try and clean anything I can out.

Can someone tell me where the fuel filter is?

It is the original plugs from 08 and I have over 150 hrs so I think I will swap them out as soon as I get up to the cottage.

Re: 2008 Glastron GT185 Questions...

Should be similar to mine, in the picture above look in the left of the photo and note the large black hose running from under the seat just behind the serp belt. You'll notice it runs to a shiny black cylinder which is going vertical, that is the fuel pump and right below that the white filter cartridge is the fuel filter.

You shouldn't run anything higher than 87 in the engine, the higher octane fuels are for engines with higher compression ratios to prevent engine knock and it also takes more heat to ignite. That might be an issue itself, and doing more harm than good really.

Fresh fuel filter, new plugs, fresh gas. If that doesn't help let us know.

Re: 2008 Glastron GT185 Questions...

Thanks for the help locating the filter.

The only time it gets the 91 is for storage and I have had to use it in a pinch since it was all I had with me in a gas can because that is what my snowmobile needs. Even the 91 caused the issues. Does anyone know what plugs they are so I can have them with me when I get to the cottage.

Thanks

Re: 2008 Glastron GT185 Questions...

91 octane is no cleaner than 87. Also, unless you are buying genuine ethanol free gas, you are getting at least 10% ethanol.

After it stumbles, does it then throttle up and run along happily, or is it fighting it's way to WOT?

Re: 2008 Glastron GT185 Questions...

lonesouth said:

91 octane is no cleaner than 87. Also, unless you are buying genuine ethanol free gas, you are getting at least 10% ethanol.

After it stumbles, does it then throttle up and run along happily, or is it fighting it's way to WOT?

Click to expand...

The 91 was gas with no ethanol. But I am sure with having used ethanol in the past it would still cause issues.

Once it's throttled up it run great.

Re: 2008 Glastron GT185 Questions...

Boat runs better with the new plugs.

Was at the dealer today to get a new fuel filter. All he gave me was a small cylindrical screen for the carbs. He explained it was all it had? Could anyone verify that I got what I needed? 3.0L Merc.

Thanks

Re: 2008 Glastron GT185 Questions...

Hi, have an 07 3.0 Volvo, should be the same set up, there is no additional in-line filter, just the one in the carb.
I've had some simlar problems, doesn't stumble ' but the idel seem to high at 900, I saw a while back Volvo had a recall on certain carbs... I still have to check into that.
good luck, Gary

Re: 2008 Glastron GT185 Questions...

Thanks Gary. I swaped it out and it still dose the little stumble. I an thinking I am going to have to pull the carbs appart and give them a good cleaning. Gona have to wait till the end of the season because the season is not that long around here.

What is the idle suppost to be? mine dose not like to idle. It will stall unless I put it in neutral and give it some gas untill the RPM's are around 900-1000.

THanks got the replys everyone!