RPM of XP150 too low?

[farginicehole]

Re: RPM of XP150 too low?

I've been told that before! Just messing with you though, of course. Well, I'm taking off and a buddy and I are going out on the boat to do a little sportdrinking, uhhh, I mean sportfishing. I'm anxious to get this thing raised up to see what happens, but will have to find a place to do it. Not sure what kind of "ceiling load" the trusses in my pole barn are rated for. I may have to do some rigging if I can't find somebody with some sort of hoist setup. I suppose I could hang a pully from a tree and use the winch on my ATV! Don't want to end up on next year's Darwin Awards though. . .

 

[MGuckin]

Re: RPM of XP150 too low?

What size are the beams in the barn and what is the unsupported span?

 

[walleyehed]

Re: RPM of XP150 too low?

Somewhere in the 8-12% range would be normal on a decent set-up, but lowering to 6-8% is possible.<br />Another key element you mentioned is being able to trim all the way up....this in itself indicates the engine is mounted way too low.<br />As we go up, handling will improve as well as RPM and speed..

 

[farginicehole]

Re: RPM of XP150 too low?

Are you talking about the vertical beams? They are treated 4x6. The trusses are 33' (yes, 33, not 32, don't ask. . .), and are all 2x6 except the "webs", which I think are 2x4 if I remember correctly.

 

[farginicehole]

Re: RPM of XP150 too low?

Well you guys are getting me all excited about unlocking some of the hidden performance of this old rig! I guess I never felt like it handled all that badly, but it sure has a ton of torque-steer at WOT!!! Gives me a good arm and shoulder workout, that's for sure. Anyways, I'm out of here, so thanks again to both of you for your replies and I'll keep you posted! With any luck, I'll have a musky story to tell tomorrow if nothing else.

 

[MGuckin]

Re: RPM of XP150 too low?

You could jam 4x4's under the 2X6 at about 8' centers should handle the weight with no problem assuming they are in good condition. <br />Thought you were going fishing?

 

[farginicehole]

Re: RPM of XP150 too low?

You thought right! I could make up some stories, but I'm not a good liar. Guess that's musky fishing though. . .<br /><br />Anyways, motor seems to be running very well, but the tach acted a little flakey again for a minute or so. It went way up over 6K, which I'm positive isn't accurate by the sound and also by the fact that when I brought it to idle, it was reading around 1800 or so rpm. Then it decided to snap out of it and returned to accurate(??) readings of around 800 or so at idle and 5500-5600 at WOT. The connections at the tach all looked okay as far as I could tell last weekend when I had it apart, but I suppose it could be something between these and the motor. Won an Ebay bid on a really nice Fluke (the one I used before was borrowed from work) DMM yesterday, so should be able to do more troubleshooting later this week. Still can trim motor all the way up at WOT and not cavitate until I go into a turn, so I'll also start figuring out a way to get that motor raised up. An adjustable jack plate would probably be nice for "optimizing" the setup, wouldn't it? Would hope that I wouldn't have to get all new steering cables & stuff (longer) to reach the motor after installing one though.

 

[walleyehed]

Re: RPM of XP150 too low?

An adjustable jack plate would probably be nice for "optimizing" the setup, wouldn't it?

Yes, it would...But, we could add a set-back plate with holes and still use the 1 in 4 hole job, but get the engine back and up and gain a hand-full there.<br />I'm going to take a pic of my 200 hanging on the plate I made and post it for you to look at...be back soon...

 

[walleyehed]

Re: RPM of XP150 too low?

 

[walleyehed]

Re: RPM of XP150 too low?

<br />

 

[farginicehole]

Re: RPM of XP150 too low?

Thanks Kenny, that looks like a pretty nice job! This would be similar to the "non-adjustable" jack plates that are available in the $100 price range, right? I could probably fabricate something like what you did here at the shop, but it might be quicker and easier for me to just pick one up. How much set-back does yours have? Did you have to go to a longer steering cable or other controls?

 

[walleyehed]

Re: RPM of XP150 too low?

6" with the alum channel..<br />I installed a steering cable when new that was 1 ft longer than needed for this reason.<br />If the throttle and shift cables were of the proper length to allow a good size circle in the splashwell, you shouldn't need to change cables..

 

[farginicehole]

Re: RPM of XP150 too low?

Saturday I went to a buddy's house and we used his electric hoist and some rope to raise my motor up on the transom. It was in the lowest position, and we moved it all the way up (4 holes) to the highest. Went to the nearest lake and ran it. My @#(% tach kept cutting out when I got up over 4K, so not sure the rpm at this point, but I actually lost about 2 mph according to my speedometer (didn't have the GPS handy - oops). It sounded like it was cavitating a little if I trimmed it up, but not too bad. Boy, it sure made a difference in the amount of steering effort it took at WOT to keep it going straight though! Before, I had to seriously strongarm it - if I let go of the steering wheel, I'm positive the boat would flip! Now I can let go, and it will just very gradually turn to the left. I kept getting a weird, sporadic chirp out of my controls and my tach would jump around exactly with the chirps. Also noticed my fishfinder started cutting out. Shut the motor off, went to re-start and had NOTHING. Jumped the starter solenoid, and the starter barely even spun. Figured we must have pulled or pinched the wires to my trim/tilt when we were raising the motor. Had to use one of my trolling deep cycles to raise the motor so we could pull the boat out on the trailer back at the launch. Anyways, got back to his house and lowered the motor back down one hole. Back at my house I found that the white wire going to some sort of potted switch by the trim/tilt must have gotten pinched and was shorting to ground (burned insulation) and killed my ignition battery out on the lake. Probably explains the chirping!? Repaired that whole mess properly and charged all batteries, but haven't been back out for another trial. Sorry for another lengthy post, but just wanted to give an update. Haven't had a chance to check my full advance timing yet.

 

[farginicehole]

Re: RPM of XP150 too low?

^

 

[Dhadley]

Re: RPM of XP150 too low?

The prop venting was probably due to the prop style / condition. Not much to worry about at this point. <br /><br />Getting the tach working properly is a must! Everything is based off of rpm & speed. Without accurate readings we're shooting in the dark. I went by the "seat of my pants feel" one time on a different prop. The boat felt faster & quicker. Bottom line -- I got beat. Ruined a perfect season.

 

[Dhadley]

Re: RPM of XP150 too low?

Kenny -- when are you putting the hydraulic cylinder in the plate?<br /><br />BTW -- that doesnt look like a Turbo II.....

 

[farginicehole]

Re: RPM of XP150 too low?

Hmmmm, that makes me think. . . I have a buddy who works for Parker Fluidpower, and he loves to fish. Yeah, I kind of figured that with a nice stainless prop in perfect condition, I might be able to put it back up to the top. And I'll figure out what's wrong that stupid tach if it kills me! I'm kind of hoping that the electrical short at that switch back by my tilt/trim has been going on for a while and might be the culprit. Anyway, it's fixed now so we'll see.

 

[walleyehed]

Re: RPM of XP150 too low?

Good to see ya back, DH... <br />I had just got back from a walleye tourney and that's a 15X17 OMC alum on there, actually cut down a bit....makes a good trolling prop.

 

[farginicehole]

Re: RPM of XP150 too low?

Been really busy lately, but finally got to get the boat back in the water last night. I had sheared my flywheel key (oops, didn't get the nut torqued to the proper 140-145 ft-lbs!), but have fixed that and another electrical short I found in some old wiring. Tach still cuts out once in a while for some reason, but when it is working, it appears to be accurate. The motor is now in the 2nd to the lowest hole on the mounting bracket (2nd to the highest motor position), and I am turning around 5900 rpm at WOT. I can move the trim ALMOST all of the way up before it starts to cavitate. Still only getting about 39-40 mph by speedometer, but forgot to take my handheld gps along to confirm. If my gear ratio is 1.75 as MG said, this is about 28% slip! Guess I need to find a way to verify my tach readings. I should also point out that when I pushed the primer in at WOT, the engine and boat speed dropped a little.

 

[farginicehole]

Re: RPM of XP150 too low?

(bump) <br />Also wondering if anybody has any comments about my new rpm and boat speed (very high prop slip?!)? I may take the boat out again tonight if the thunderstorms hold off, and I'll try to remember to take along the gps this time. The seat of my pants still tell me I'm in the 40 mph range though, despite the pickup of several hundred rpm.