Prop removal questions...

JoeinNY wrote: halfnelly wrote: Well, the time with the 1868 was short lived. Yesterday I hit something while backing it off the trailer and bent one of the blades. The same thing happened with the 422 I have, I must have had 3 uses out of it before I whacked something. Same lake, same ramp. I put the "old reliable" 14x16 OJ back on while I send the 422 and 1868 to Admiral C&B for repairs. Time to petition the HOA to pony up the dough to get our ramp cleaned out and dredged. Ouch, are you sure it isn't the prop guard on the trailer.. there are some out there known to be blade benders.

Nope, definitely trash on the bottom. I was well clear of the trailer both times, it was something soft like an old branch or something. Probably would have been OK if it wasn't in reverse, which tends to bend blades a lot worse.

Our neighborhood ramp is private and didn't get much use for 10+ years until we moved in, so every plant, stick, branch, rope, etc. has piled up along with 2 feet of Florida muck. I try not to run the boat much in close to shore because it clogs up the strainer with weeds and algae, but of course yesterday was the exception.

63 Skier wrote: I've finally got numbers on my new 1442. First, strange thing happened with the stock OJ 13x16 4 blade. Until I dinged it, I was getting 44.5 mph at 4,600 rpm. I sent it out for recondition and put it back on first. I could tell from the first minute that something was different with it, had less bite at idle in gear. Here's the numbers I got with it after recon: OJ 13x16 4 blade rpm   mph 2000 13.0 2500 22.2 3000 28.0 3500 32.3 4000 36.4 5230 44.7 WOT Crazy, huh? They must have really altered the prop when they reconditioned it. On to the 1442, here's the numbers today: Acme 1442 3 blade rpm   mph 2000 13.1 2500 22.0 3000 28.2 3500 33.3 4000 37.6 5180 45.4 WOT The prop felt great, excellent holeshot. I hope to get behind it on the ski in the next few days. At 4800 rpm the speed was 43.6 mph. Even though the numbers for the 2 props seem similar, the Acme felt much better, more responsive. All numbers were with 1/4 tank of fuel, fair amount of gear in the trunk and ski in the locker, just me in the boat, light breeze. Now if I can stay away from rocks ......

I've been meaning to post an update for a while, finally am getting to it. I'm enjoying the 422 I put on at the beginning of the season, seems like the perfect prop for this boat for my use. Here's the numbers:

Acme 422 4 blade
rpm   mph

2000 13.2
2500 24.0
3000 29.7
3500 35.1
4000 36.6
4500 42.8
4940 45.4 WOT

32 mph ski speed is at 3210 rpm

1/2 tank of fuel, light breeze, my usual ton of gear in the trunk, Flitepipe was in place, just me in the boat. Smooth as smooth can be at all speeds. I was surprised at the same WOT speed as the 1442, my first pass had 45.2 mph but 2nd time gave it a bit more room to find a top speed. All numbers off of perfect pass in rpm mode.

Stargazer.

I'm want to start looking for a new prop for my 95 Sport and rather than start a new thread I thought I'd add to this one. After doing some reading it appears the 422 is probably what I need. I'm planning on using the boat mostly for wakeboarding but would also like to keep some top end speed as I am interested in learning to barefoot. I'll be running at pretty much sea level. At WOT I got 43.1 mph at 4560rpm both measured using perfect pass Stargazer.

I believe I have the stock prop on the boat but I'm not sure how I confirm that.

I'm probably a couple month away from buying so I am open to any kind of testing to get performance number to help make the right decision

Blamey wrote: I believe I have the stock prop on the boat but I'm not sure how I confirm that.

Take the nut off and read what it says on the hub.

So looks like I gained 0.4 mph on the top end my WOT numbers are now 43.5 mph at 4560 rpm. Overall the prop is much smoother. I honestly can't notice much difference in hole shot but I haven't had the boat for long. Across the RPM range I have added about 0.5 MPH. (at 3000,3500, 4000) vs the stock OJ.

So overall the boat runs great. Good news is I don't have a slow hull, Bad News is I am probably missing a few ponies since I can only get up to 4450 RPM max and top speed is 43.5mph. This makes sense because I had low compression on a couple cylinders when I tested the engine before buying. That's something I plan to address in the future but for now I am just enjoying the boat.

Overall I am happy with the 422, hope my results will help other make a decision.

gun-driver wrote: What motor do you have?

Looks like a GT-40 from his diary listing. He can gain an easy 3 mph with better compression, but it's a lot of work for 3 mph.

tryathlete wrote: gun-driver wrote: What motor do you have? Looks like a GT-40 from his diary listing. He can gain an easy 3 mph with better compression, but it's a lot of work for 3 mph.

Those RPM numbers are way low for a GT-40 with that prop

MrMcD wrote: I think he stated he is in Denver, 6,000 foot elevation will rob some power.

That would make sense but his profile says NY that's what was throwing me.

KENO wrote: If it's Blarney you're talking about he states he's using the boat pretty much at sea level a handfull of posts back. If Denver's at sea level, we all have a lot of problems (except LC Gordon who now would have a better running boat) Now White Plains NY.........that's pretty much at sea level.

Yup, I'm in White Plains NY and I run my boat on Greenwood Lake. I think it's at 700ft, so no altitude issues.

And yes, I have a GT40. The boat does have compression issues. It's something I knew about when I purchased it. I haven't done a leak down yet since I don't have the money to fix the engine but hope to get it looked at some day.

Im pretty sure the compression issues that are affected my top end but really if there are any other suggestions to look at I'd appreciate the help.

gun-driver wrote: I guess we can start with what are the current compression numbers? Have you done anything to it like a tune up? How do the plugs look black, brown, wet, worn? Is the air cleaner/spark arrester clean?

Well that's interesting because I was not aware that most of the above should be done.. To all the service items the answer is no. The flame arrestor is dirty and I've been meaning to clean it but keep keep forgetting to take it out.

All i have done is the regular stuff. Oil and filter change, trans fluid change and fuel filter change. I also ran some fuel cleaner through the system.

I was going to change the spark plugs and I have new ones. I have been researching the doing a tune up the week but figured since I wasn't noticing any miss firing issues it wasn't to important. Same goes for wires. Do you think this could help?

I'll try pull the compression numbers from an old post but I'm on my phone now.

Edit: Here are the compression numbers from last year when I bought the boat.

1. 120
2. 100
3. 120
4. 110
5. 120
6. 110
7. 90
8. 120

I would do what Jpass said and see if the numbers are the same now that you've been running it.
I know your not worried about getting into the compression problem until after the season but the other things may help get better performance until then.
Also take a peek inside the cap to see what kind of condition it's in.

63 Skier wrote: I guess if it was me I'd take a look at, and likely change, the plugs, inspect the wires, cap and rotor, and maybe most of all get a timing light on it. Would be nice to know you have good ignition and are timed right.

Thanks for all the advice everyone.

The prop I had on before had a few decent sized nicks in it and I wasn't sure if that was affecting performance, turns out it was but not by much. With the new prop I now know I have an issue but figured it was just due to the low compression. Now that I know a tune-up could help I'll look into getting that done.

Should I just go ahead and replace the cap and rotor, wires and plugs? I'll probably start a new post on this tomorrow.

Not sure how to use a timing light, guess that something new to learn.

GT-40 computer advances spark not distributor per say.

I have never checked my GT40 timing assuming it was controlled by the computer and it has run very well since I have had it. 30 degree's seems very tame to me.
I would think you would benefit from moving the total advance to 34-36 degree's.
Try 34 and if you have no ignition rattle or pinging try 36. Timing should be all in by 3,500 RPM. for max power. If you bring it in too early you can cause detonation issues and risk damage so be conservative with changes.