Should i change? BCB

yes!!! Raise it up some. You should be getting almost 70 with that boat. Im gonna take a guess and say bring it up a half inch, and see what she does. Have fun with her.Dan Yonan. ———————————————————

It has a new water pump also, i forgot to mention. The fastest ive ever had it was 53 @ 5600, Its an old motor so i know i aint looking at 70. I actually was gonna try tonight but to raise the jackplate tonihgt i couldnt find a allenhead that fit it. Any idea what size allenhead that is in there, my Water presuure gauge reads 10psi most of the time but goes up to 15 at WOT. heres a pic of the lower unit and jackplate maybe it will help ya Tell me what do try next, so theres 3 more water inlet holes?

Before you go any further, I have a 1992 XR6. Has 175hp carbs and an opened up exhaust, and it will push my 18 boat past 80mph with a 28″ chopper. Age doesnt mean a lot of the motor has been taken care of. Check the compression. XR6 ought to be 120-125psi on all 6 cylinders, with the lowest and highest being within 12psi of each other. If you get that, the motor isnt “tired”. 4″ plus below the pad sounds like you are way low and have everything buried deep in the water. The older XR6s had a series of holes on each side to admit water. As BCB mentioned, some good stainless allen screws can be used. I actually tapped mine, but you can probably just thread them in using loctite and be done. You want to plug the top 3 to avoid sucking air instead of water. You can also install water inlet scoops if you can find some, although mine runs quite high and maintains 12psi at WOT. It does need trimming down in a turn or pressure will drop off. BTW a 23″ laser II is not a great prop. I assume this is the usual small gearcase used on the early year XR6s before merc went to the normal gearcase. If so its a 1.78 ratio and a 24-25″ should not be a problem. Those motors are _very_ difficult to get past 5400-5500, because of the ridiculous exhaust tuner they used. Produces a ton of low-end torque, so ramp up the pitch a bit and Ill bet you will see big gains. Mine will almost run the same rpm no matter what prop I put on it, until I go too far and start go bog it. But at least dump the laser and go to a more modern blade shape…Last edited by oldtimer57 on April 23rd, 2009, 5:52 am, edited 1 time in total.2008 Pantera Classic2014 Mercury Pro XS 200

Couple of things. 1. yes, 95 is too low. Could be anything. Stuck ring (you might try spraying something like ring-free in thru the spark plug hole, turning the thing over by hand, repeating a couple of times, then let it sit before cranking it up on the water hose with muffs. Could be a broken ring. You didnt mention which cylinder. Hopefully it is not #1 (upper right looking at motor from back). That is the one most likely to run hot and cause piston/cylinder wall damage. If you want, it is easy to pull the cylinder head on that side, then turn the motor by hand to move the low psi piston to bottom dead center, then look at the cylinder wall. Smooth? What about around the exhaust port? Clean? No groves. No signs of scuffing? 2. If your lower unit has 6 holes, plug top 3 or 4. If it has 4, plug top 2. Just leaving one on each side is pushing things a bit. 3. You said “no hole shot”. What does that mean? Does motor just bog and take forever? Raise the jack plate some. Does the motor wind up to 5000 RPM quickly and feel like the prop is slipping? You need smaller PVS plugs if you have them, or the motor could be too high or have too small a prop diameter. You usually end up with prop ventilation when the jack plate is raised. This increases top speed to a point, but the slippage at low speeds results in slower acceleration. Also, you tried a 25″ but which prop? One of the newer tempest-type props with PVS plugs? play with those. An older laser? Keep looking for newer props. You are riding a one-speed bicycle. You can gear it to pull up hills but go slow when level, or you can gear it to go fast when level but have to really work to get up the hill. You cant have both with a fixed-pitch prop. First step is to always make sure you are getting your 165 horses or so (XR6 was a _strong_ motor with a ton of low-end grunt thanks to the 2.5 liter block). Then make sure you have the right prop and shaft height. If you have the power, and get the right prop, and get it set up properly, it will fly. I will add that the XR6 didnt have a chromed cylinder wall. That was only on the 200hp version (same block, different sleeves in the cylinders). You could re-sleeve the block for under $200 if you disassembled it yourself. A shop will be way more expensive because the block has to be stripped bare (no crank or anything) before you heat it to release the sleeve. Ive heard of at least one person using liquid nitrogen to cool a sleeve and pull it out without having to take it to a shop that has an oven big enough to bake the thing to get the block to “let go” of the sleeve. If you are that brave, the sleeve is under $100 bucks. Losing the chrome plating would certainly wreck compression on that cylinder and it would continue to get worse as the rings wear (the 200 rings are different than the 150/175 rings as well because of the chrome-plated bore). On an old motor I would suspect stuck or broken rings, particularly if I removed the head and see no obvious cylinder wall damage. Thats a cheap do-it-yourself fix given a couple of days. It is an expensive shop fix. Ring-free might unstick a stuck ring, although I have personally had no luck with that. But I have heard of those that were successful. BTW, your trim angle looks pretty good to me. Perhaps a tiny bit more up trim, but you are shooting for having those cowl stripes exactly parallel to the surface of the water, which is optimum to turn every bit of thrust the prop generates into forward motion. You do have a _ton_ of wetted running surface however, which does look strange, if you are running upwards of 50mph. Got a couple of hundred pounds of jigs or something in the front compartment? Last edited by oldtimer57 on April 23rd, 2009, 11:55 pm, edited 4 times in total.2008 Pantera Classic2014 Mercury Pro XS 200