250R on Bullet 20XDC Need set up help

**owenssw** · 05-05-2020, 01:55 PM

I already posted a couple times about this combo, but now that I've had time to run it and learn some pro's and con's, I thought I would ask for thoughts again.

250R Flashed to 325hp (6700 rpm rev limiter)
Sportmaster with 1:75's
Bullet 20 XDC
12" set back
1-1/4 above pad
Currently running a 28 Bravo XS (going to try a 30 this week)

All my testing has been with 2 guys on board, full tank of fuel, full livewell, tournament loaded to fish.

Pro's:
** Boat is an absolute rocket out of the hole
** Boat rides higher in the stern and bow which makes for a better ride in rough water
** Mid range is insane, pulls like a freight train on steroids
** Over-all a blast to drive
Con's
** Because of the added lift the boat gets really loose over 80 mph like its wanting to go into a GC blow-out
** Unable to run the boat up past 6200 rpm because it gets too loose as stated above (mainly when backing off the throttle) its not a chine walk, its a get loose no control thing (blow out)

** Because of the issues above I'm unable to get a good test with different props

When I bought the boat new in 2003, I had a modified 280 on it and was running ~100 mph. With this new set up I'm having to learn to drive the boat all over again, so I'm sure that's part of it too, but I've been driving this boat for 20 years and over 100 mph regularly, so I'm not a beginner at running fast, but it gets my attention every time I try and run it out.

I'm thinking its partly due to the larger sportmaster causing some of the issue.

My goal it to run low 90's loaded, which I believe is very do-able. I'm running 83.7 at 6200 rpm with the 28 Bravo (and can spin it to 6700 easily), and I can give some up on low end to turn a bigger wheel

Any thoughts??

**Bateman** · 05-07-2020, 10:56 AM

I’m not sure it will help, but I took a 21xd out last Saturday with a 250R. Are the hulls similar enough that I could pull some measurements and compare?

The 21xd handled beautifully. Want to say it’s a 92mph boat, but the owner was not along for the ride and I was a little white knuckled lol. Ran up on 70 smooth as can be though. I’ll get some numbers this weekend if you think it might help.

**owenssw** · 05-07-2020, 01:21 PM

I really think it might give me a good idea. I can run 70's no prob, when I push it into the mid 80's, mainly when slowing down, it feels like it trying to blow out.

Thank you for taking time to try and help me, I really appreciate it.

What gear case and gears does he have? I'm running a sportmaster with 1:75's

**Bateman** · 05-07-2020, 02:01 PM

No prob at all. I will get in touch with my neighbor by this weekend and get some measurements. I will go through some pics I have of the boat and see if they can give an idea until I can lay my hands on it.

I’m not sure of the gear case. I will ask.

**C.Warrix** · 05-09-2020, 05:21 AM

My 21xdc 300r would get a bit squirrely when I backed off the throttle...found I had some air in the hydraulic steering system..bought a bubble purge 2 and bled the system..problem solved...Look at the bubble purge on you tube

**RIVERRUMMER 70** · 05-12-2020, 08:40 AM

Originally Posted by owenssw

I already posted a couple times about this combo, but now that I've had time to run it and learn some pro's and con's, I thought I would ask for thoughts again.

250R Flashed to 325hp (6700 rpm rev limiter)
Sportmaster with 1:75's
Bullet 20 XDC
12" set back
1-1/4 above pad
Currently running a 28 Bravo XS (going to try a 30 this week)

All my testing has been with 2 guys on board, full tank of fuel, full livewell, tournament loaded to fish.

Pro's:
** Boat is an absolute rocket out of the hole
** Boat rides higher in the stern and bow which makes for a better ride in rough water
** Mid range is insane, pulls like a freight train on steroids
** Over-all a blast to drive
Con's
** Because of the added lift the boat gets really loose over 80 mph like its wanting to go into a GC blow-out
** Unable to run the boat up past 6200 rpm because it gets too loose as stated above (mainly when backing off the throttle) its not a chine walk, its a get loose no control thing (blow out)

** Because of the issues above I'm unable to get a good test with different props

When I bought the boat new in 2003, I had a modified 280 on it and was running ~100 mph. With this new set up I'm having to learn to drive the boat all over again, so I'm sure that's part of it too, but I've been driving this boat for 20 years and over 100 mph regularly, so I'm not a beginner at running fast, but it gets my attention every time I try and run it out.

I'm thinking its partly due to the larger sportmaster causing some of the issue.

My goal it to run low 90's loaded, which I believe is very do-able. I'm running 83.7 at 6200 rpm with the 28 Bravo (and can spin it to 6700 easily), and I can give some up on low end to turn a bigger wheel

Any thoughts??

Try some overhub style props that bravo " barrel size" is like a skid planer when you get moving and the case also....combined its like sliding on half sheet of plywood ....what prop did you use on the 280 rig....?

**owenssw** · 05-12-2020, 10:56 AM

Riverrummer 70, You said it perfectly, it is like sliding on a piece of plywood. You read my mind, I actually talked to my prop guy early yesterday morning asking if he has any over the hub styles that I could try. When I had the 280 I was running a 28 bullet cut chopper and Lightning ET, both were great props on the 280.

I talked to a dealer in Texas yesterday and he said he recently rigged a 20XDC with a stock 250R and is running mid 90's. He wasn't willing to share any info, just said he could do the same for me if I brought him my boat, which I'm willing to do, but he's 14 hours away from me so that makes it a little difficult. I offered to pay him for his set up info, but he wasn't interested.

C. Warrix, I ordered a bubble purge yesterday. That sure could be part of the issue. I watched the youtube on it, there is no way I got all the air out doing it the way I did. Hoping that takes some the "lose" out of the steering when backing off.

**owenssw** · 05-12-2020, 12:18 PM

Got with Brian at Prop City again today. He is sending me (2) over the hub props to try, one is a 30p 4 blade, not sure what brand, he custom built them for his 30' cat running (2) 300xs's, the other is a 32 3 blade, looks similar to a lightning ET but it's not. This is going to be a complete crap shoot, but like Riverrummer, I've had this thought in the back of my mind for a while to try over the hub props. Never know....

If you guys ever need anything as far as props, I highly recommend getting with Brian at Prop City in Oklahoma City. He has went out of his way to help me. He will box and ship just about any prop you can think of for you to try. Absolutely a super helpful guy. Also has a lot of knowledge, Brian has been building props and racing for 35+ years. He is a great resource!

**Bateman** · 05-13-2020, 07:24 AM

Owenssw, I didn’t see my friend this weekend due to weather, but I was able to pull up some pics. The pics showed that I’m an idiot lol. My friends boat has a 250xs that has a “Racing 250” cowl and I assumed it was an R. I doubt that would help you much.

sounds like you are on the right path. Lots of very knowledgeable guys to help here.

**owenssw** · 05-13-2020, 07:59 AM

Bateman, thank you for taking time to check, I appreciate it!!

I failed to mention that I tried a 29p Bravo Lab Finish this past weekend, and was super impressed, only down side is I'm not going to see the top speed that I had hoped for, but the hole shot (loaded) and mid range is crazy good. It had 3/16" cut off the flare and that settled the boat down in the stern a lot. So far, that's for sure a prop I would like to have at least as a back up, but not done trying yet.

**Bateman** · 05-13-2020, 08:08 AM

Nothing wrong with multiple props! Sometimes you just need to bust out the top end prop to make a point haha.

keep us updated on the progress

**owenssw** · 05-13-2020, 10:25 AM

Bateman you got that right, sometimes you just gotta let the big dog eat and make sure the poodles are watching, just in case there was any doubt in their minds....lol

I'll keep you posted

**owenssw** · 05-15-2020, 08:06 AM

I ran a 30pt Signature over the hub 4 blade last night. Boat had a lot of bow rise when taking off, but didn't blow out at all, mid range was lazy compared to the Bravo's I've tried, condition didn't allow me to air it out but ran 83 mph at 5800 rpm. I do all my testing with full tank of fuel, full live well, 2 guys and tournament loaded. I could tell the weight is what was keeping this prop from performing to its potential. If a guy is running light, and wanting a top end prop, the over the hub might be a player on these v8's. I was surprised, the over hub had less slip on break over than the Bravo 4 blades. (I've kept the motor height the same for all my testing, not sure it where it needs to be, but that way I can tell the differences in the props).

**RIVERRUMMER 70** · 05-20-2020, 11:29 PM

need to test the overhubs higher as that is the point of those props..... testing them at same height is not a good gauge for that style prop....
running a surface style prop too low is as bad as running a thru hub style prop too high and your doing both ...lol

**owenssw** · 05-21-2020, 02:12 PM

Riverrummer, thank you for the info, I'll forsure raise the motor before I try another over the hub. My prop guy is having a 5 blade over the hub cast, and he's going to work it as needed and try to hit the sweet spot for me. I believe it's a 15-3/8 dia. 5 blade (over hub) with blades that resemble more of the Bravo than cleaver style blades, which might help.

I'm only at 1" above pad, I tried running 1-1/2 above but it blow as out bad getting on plane, but that was with a Bravo through hub, I never tried an over the hub at 1-1/2 above pad, so will do more experimenting for sure