A 1/4" npt fitting has about a half inch OD, so a half inch hose barb and a 1/4" npt are about the same size on the inside. If you're concerned about this sort of thing take a good look at your fittings because they vary greatly in how they ate made some have much bigger or smaller inside diameter, especially the elbows
OEM 155 Pump Talk
- Thread starter DAG
- Start date
hornedogg79
dodgin' bass boats
Been looking forward to testing a oem 155 for some time now. Followed this thread since the start. Finally took the pump and shoe from a B2 last year and started grinding on my Chan last fall. Got it all back together this past week and so far it's pretty disappointing. I've gone from being able to flip twice fairly consistently to barely nosing one in. Switched from a Skat setback mag 144, C75 14/19, 65v nozzle @85mm... to a B2 155, E75 5/10 5mm cutback, nozzle @89mm. Motor is a stock stroke xscream 900, Pfp dry. It feels too tight right now. My previous setup was revving higher before I left the water. Now it seems to lug a bit. My next steps will be a smaller cone and shimming the prop back out. Hoping to at least get back what I had.
Last edited:
- Location
- CT
that doesnt seem like enough prop for that motor. i pull more prop with a ported 760.
Jcary85
Site Supporter
- Location
- Glenmoore pa
I agree. I ran a 7/14 with a 781 and stock 155 in a havoc. It was perfect. Something is off. A loose pump (your previous setup) could mask tuning issues.
- Location
- Lake Orion, MI
Pressure test your PFP chamber. If it's broke that would explain the lag/lack of rev feeling you're experiencing. Ski will sound great out of the water but as soon as it hits water you can feel a very inconsistent ski.
Like others said, you should be pulling at least a 9/15 - 10/16 with that setup. Try the smaller cone, I wouldn't mess with the shimming of the prop as the further away you get from the stator the less hookup/pull youll have. (everytime ive tried this my ski just feels like mush and looses any snap)
hornedogg79
dodgin' bass boats
I've ran this motor for several years now and know it pretty well. Ended up pitched nearly the same as a 760 with the 144 pump too. I can go taller but that's not what it's telling me. Not boiling the prop. I did up to 4 flips in a row before. Haven't seen many stock strokes (or poorly tuned skis) capable of that. Pfp was pressure tested last week. Only other thing I changed was ignition. Msd enhancer to 62t zeel. Fresh top end. Motor sounds crisp as ever. Thrust just isn't there. I tried stock nozzle bore first and it was way worse. Going to 89 helped.
Jcary85
Site Supporter
- Location
- Glenmoore pa
Check the zeel curve. Make sure you have all the timing in by like 1800. Wax curve brings timing in pretty late and makes bottom feel a little laggy.
Do you have 62t or 61x electrics?
hornedogg79
dodgin' bass boats
62t, lightened stock flywheel.
Before with the enhancer my stator was advanced 3.5mm
Jcary85
Site Supporter
- Location
- Glenmoore pa
Enhancer advanced 3.5 degrees probably gave u 28ish degrees advance starting at 1k rpm or so. Probably more than You have now below 3k if you are running the off the shelf wax curve. Just sayin’
Big Kahuna
Administrator
- Location
- Tuscaloosa, AL
he already tried that, said stock was worse than the larger one.
hornedogg79
dodgin' bass boats
Yeah going from stock 63M @86.5mm to the bored one @89 was an improvement and I was able to land a clean setup wake flip last night. Had to go fast into the wake though. Before, I could do ugly idle flips and 3/4 throttle setup wake flips. Thanks for the suggestions guys, I have a few things to try now. It's not terrible. I just know it can be better.
hornedogg79
dodgin' bass boats
Made big gains yesterday with the pump. I have a zeel cable on the way but wanted to try some free adjustments. Shimmed my prop back to stock, non cutback location. Before I could feel my pump loading up just putting around and my motor wasn't making that sweet music that I'm used to. Idling out of the cove I could immediately tell it was a step in the right direction. Motor sounded happier. Was able to ride out all flip attempts with my new long ride plate on.. I have more thrust right off bottom but still missing some top end kick compared to my skat sb144. Anxious to try a more aggressive timing curve. Didn't realize the supplied curve was so mild. Imo, 5/10 really doesn't seem far off for this 875cc stock stroke. Every hull/intake preloads a little different too. What works in my hull may not in another. Chan loads pump harder than most. Haven't run a scoop grate on it in years.
Jon I have a fully bored out 155 with fins removed cone but it’s the w/ trim model. I actually have two different ones. One is 3.5* gutted and bored the other 5* non-bored. I noticed that the added cone angle made it worse. Of course your welcome to anything I have, you know that. I just got my ski out and started disassembly for rebuilding everything. I am going to get away from the trim for simplicity and ordered a new pump cone the other day.
Attachments
Whoa! Glad to see it
I hate to say it but I think you would have been better off keeping the skat 144. At the end of the day pump size gets blown out of proportion imo. A better smaller pump is more beneficial then a larger poopty pump.
hornedogg79
dodgin' bass boats
I have to agree. I just wanted to see for myself. My ss900 & skat144 are getting back together in a new hull.