Carver 400 MY engine RPM issue

[tomschauer]

At least the ethanol reduces our dependence on foreign oil.

[hausherrs]

Yesterday I pulled a plug out of the top of the tank so I can get the bore scope camera in there. I found where the black beads in the Oberg are coming from. The rubber gasket used for the inspection port. The previous owner said he replaced those gaskets with ethanol approved rubber gaskets. Ether he didn’t or he didn’t replace all 4.

Tank is full so I have to get out the ole shop-vac and vacuum out the fuel. IM KIDDING!

Anyone have recommendation on rubber gasket material that is resistant to ethanol?

[cpoint]

Well I had the fuel filtered in the tank. Since it was fresh fuel, and no water issue. I was seing particles in the filter. and attached image shows what came out of the tank (port side). Unfortunately it is still making the tach fluctuate. I may have to get them back again once I have lesser fuel in the tank to make sure all is pulled out from the fuel. They were using 5 micron filter to clean my fuel directly in the tank. And he said he came accoross some material at the corner (low point) and when he started hitting it with the small pipe that was gettting fuel to the filteration, chunks broke up and got sucked into filter. Now why the tach is still fluctuating little by little? is there a filter in the engine other than the one that I replace coming from fuel line to the engine block? they said there may be a 10 micron filter that mechanics may need access? I did change the filter today and did not see too much particles so maybe tank is cleaner now, but is it possile previously some small ones got thro the 25 micron fuel water seperation filter?

[km1125]

I'm getting confused between the two different issues being discussed here. cpoint, if you have merc 8.1's then there is another filter on the engine... small in-line one.

[cpoint]

Thanks, maybe that may have some small particles than (I mean the in-line-filter). I'll see if that's something I can deal with all call the mechanic. I took her out today, did not pass 2500 RPM, just wanted to have relaxed ride, no movements on the tachometer for about 2 hour ride. so maybe all that got cleaned up. Next time I will take it up past 2500 RPM and see any issues, if so will call the guys back to maybe filter again.

[km1125]

A friend of mine has a 356 with 8.1's and he has had to frequently change the small filter on the engine. He keeps spares aboard and has even changed them enroute while someone else mans the helm with just the other engine providing revolutions.

[cpoint]

Source of the post A friend of mine has a 356 with 8.1's and he has had to frequently change the small filter on the engine. He keeps spares aboard and has even changed them enroute while someone else mans the helm with just the other engine providing revolutions.

That sample to change, where is it located (I mean the filter)?

[cpoint]

Actually I have Mercruiser 7.4 liter MPI. My mistake on previous posts. So with that, is there an inline fuel filter on that engine? can anyone point me in right direction where I may find it. Is it easy access to change, or do I need to dump more green stuff to a mechanic

Now when I get near 3000 rpm I get tach fluctuation. even if I replace the filter now. So I am thinking if there is an inline fuel filter, and some stuff reached it through water seperation filter, may be causing the problem. I just want to confirm that before I call the guys back that filtered my port tank.

Thanks all.

[waybomb]

Put your hand on the fuel line and follow it back to the tank. If there's a filter there, you'll run into it. The PO may have even installed one after the fact.

[cpoint]

Source of the post Put your hand on the fuel line and follow it back to the tank. If there's a filter there, you'll run into it. The PO may have even installed one after the fact.

Thanks, will take a look this weekend. I looked at oll manuals I found online, and can't tell where the OEM has it if there is one on 2000 model.