New boat, lots of problems

[zsites]

Ok, I am completley new to the boating world but I reciently bought a 83 19ft Renken with a Mercruiser 120. I changed the oil. Took it out last weekend and found some problems. First of all if was difficult to get started, (as compared to out of water with muffs) cranked over well but hard to start even after runing all day. 2nd there was a loud sucking noise coming from the carb and every once and a while it would backfire through it. Noticed small amount of oil around the flame arrestor cover. 3rd, At WOT it is only reving about 3100 RPM at 28 MPH. (GPS) with 4 middle weight people in it. Is this normal? Not sure of the prop size. I pulled the dist. cap last night and the points/ condensor look new. Plugs and wires are a different story. Replacing them tonight. Also having problems locating the fuel filter. It does have a water seperator. Any help is greatly appreciated.

 

[liquidlew]

Re: New boat, lots of problems

You need to do a complete tune up, along with plugs and wires, check the timing, which you will need a manual for that (should have one anyway, or go to the Adults Only sticky and find your manual) and a timing light, and do a compression check! I had the same problem, boat would start great on muffs but after running it in the water and shutting it off, it was very hard to start or wouldn't start at all. Did tune up, had carb rebuilt but still had same problem. Finally did a compression check and found very low compression in one of the cyls. due to bent valves. Did valve job which corrected the compression problem, now my boat starts up on one click (or 2) every time! Low compression could also be the reason for the low rpms. Good luck!

 

[cooter2506]

Re: New boat, lots of problems

Welcome to iboats!!!!!!!!! Do a complete tune up. points and all. Your backfiring thru the carb is a lean fuel condition. COuld be water in the seperator but that gets change in a tune up. Dump the contents of th old seperator ino a clear GLASS container and look for water. If it has water you could have some water in your tank you need to remove. Now the WOT issue could be taken care of with the tunup but if not look up in the adult only sticky for the WOT issues and go thru that list, do it all and dont skip anything. Good luck and keep us posted

 

[180shabah]

Re: New boat, lots of problems

Loud sucking noise is normal.

Full tune up is a must - replace the points and condensor, set dwell, set timing, new plugs, wires, cap and rotor.

Does it or dos it not have an external fuel filter? Water seperator is also a filter. If it does have a seperator, dump the contents into a jar, is it all gas, or is there also water? did you pull the fuel inlet to the carb, should be a filter in there.

Agreed - need compression and vacuum tests and get the manual.

Any gas in the clear overflow tube from the fuel pump? should be empty.

Verify both the WOT speed (GPS) and RPM (shop tach). 19' boat, with 4cyl, 4 guys onboard, 3100RPM and 28 mph just sounds a little optimistic.

 

[Aviator5]

Re: New boat, lots of problems

I doubt that loud sucking noise is normal. I had it when I by accident (too much beer) put the carb gasket the other way around. and it would backfire also.

 

[zsites]

Re: New boat, lots of problems

Ok, I pulled the water seperator off last night and found that what was inside it looked very bad. Water, gas, and dirt. Kind of copper- brownish in color. Also the spark plugs were very black. No oil present on them tho. So now im assuming that I will have to somehow flush the tank and possibly rebuild the carb?

 

[Arabian180]

Re: New boat, lots of problems

Loud sucking noise could be a vacuum leak.
Backfire could be caused by lean condition caused by the vacuum leak.
Hard to start could be caused by the vacuum leak also.
Check all around the carb and related hoses. You may have knocked off or forgotten to replace a vacuum plug or hose.

Flushing the tank? maybe
Rebuilding the carb? only if you feel adventurous and think that the filter didn't do it's job.

 

[180shabah]

Re: New boat, lots of problems

Thanks for the input, sunshine.

 

[IVAZ]

Re: New boat, lots of problems

i think you probably need a canuter valve replacement, along with a set of new muffler bearings. also check your blinker fluid levels. good luck, and you problably got screwed on the price.

Very odd name you chose. Your advice is not good either.