no top end, trouble shooting ideas needed!!!

[bouch1]

I have 120 force on a 93 bayliner 1800, worked great until tubing 2 weeks ago when I had only 3/4 speed at WOT, was about 8-10 mph slower with sluggish out of hole, when I looked it over after it appeared maybe too much oil in gas mix, plugs were oily especially #1, spark arrester on top carb was very oily, could too much cause no top end, rpm seemed lower too (no tach yet), cleaned carb etc. and ran the other day, seemed a little better but still no full top end, compression check (cold with plug gauge) WOT read 101,125,130,130, I will pick up a screw in when I can and retry but I will take any ideas to troubleshoot in the meantime,,, Thanks for any help...

 

[roscoe]

Re: trouble shooting ideas needed!!!

Re: trouble shooting ideas needed!!!

Check for a strong spark on all 4 .

Make sure carb butterfly is full open when you go full throttle.

 

[bentle]

Re: no top end, trouble shooting ideas needed!!!

Compression is key here. 101 is to low when compared to 125 and upward. Do a decarb and recheck your compression. Also make sure your battery is fully charged. You will need full cranking rpms to get your best reading at wot.

 

[jerryjerry05]

Re: no top end, trouble shooting ideas needed!!!

Comp should be even on all 4.within 5#.
A good reading is 150# get a different guage and try again.Make sure the plugs are out when testing.What do the plugs look like?Any wet or excessive oily plugs.
Spray some oil in the cylinders and see if it make any difference.
Then remove the head and inspect the gasket and cylinders
.Lower comp between adjacent cylinders could be a bad gasket???

 

[mrdibs1]

Re: no top end, trouble shooting ideas needed!!!

Simplest answer with your compression numbers is a blown head gasket.

 

[bouch1]

Re: no top end, trouble shooting ideas needed!!!

thanks, will start checking when IRENE blows over and I get time to work on it.