I've got an 88 XR 4 (serial number is in my signature). Anyway we took her out just my wife, me and a few rods and I could only get 46mph out of her for some reason. Boat is an 88 Ranger 374v with a 6" jackplate. Motor was gone through and was fine this spring. She hopes up on pla e just fine. Could only turn 4900 rpms though. It has the smaller gear case and is running a 22p Laser2. Rpms seem low? Any ideas?
0G886873 Mercury Serial Number
2000 Bass Cat Pantera III with 200 Merc
check basics spark ,fuel delivery, compression, linkage and or hot foot
.................................................. ...the scariest thing in life is the unknown ...................................
I have a 90 XR4 (small gear case) that runs the exact same numbers when using a 22P Laser II. I went with a 20P Laser II to increase RPM without loss of speed. Ive found the best prop to achieve 5400-5600 RPM is a 14x19P but my top speed is around 45 MPH.
Last edited by danover321; 06-10-2019 at 06:38 PM.
1990 ProCraft ProCaster 180
Merc XR4 150 Blackmax
I have an 88 XR4 on a 374V and she's having issues too. Yours should be turning about 5600 rpm at wot. I'm running a 5" plate and a 24" pitch, 4 blade.
I forgot to ask, were you running the Laser II 22P during the spring or have you just started using the prop? Increasing pitch can reduce rpms.
Last edited by danover321; 06-12-2019 at 07:09 PM.
1990 ProCraft ProCaster 180
Merc XR4 150 Blackmax
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