speedysprocket
Alex
- Location
- Chesapeake, VA
Could your power valve springs be too soft and letting the valves open too early, killing your bottom end port timing...?
Custom/Hybrid bottom end
- Thread starter 102nd7
- Start date
chadman154
#Itsonlymoney !!!!!
- Location
- Dirty south
Let me get this straight. You think the motor doesnt have low end power? But your going to decline any help from the motor builder and his advice. ( Im gonna go take my Ferrari to the volvo dealer for service cause i dont want help from the builder, good call)
Enough sarcasm... have you checked your timing with a light, maybe your timing is WAY off......
- Location
- marion ohio
And no I have not checked timing with a light as I am unaware of any timing marks on the flywheel. The stator was set using the factory markings.
Christian_83
Xscream
- Location
- Denmark
1 Total loss kicks A$$, revs and give that kick in the bottom end.
2. if you are tuning in, pump, carbs or engine and are having troubles. write all your settings down with dates and pro/cons. So you can track back problems / gain/loss.
Im running a Dasa SS 850 in a KDX, PFP, dual FS 49 and MSD TL. with a 155 OEM pump and a 7/13 mag prop.
The 155 really gave a boost from the 144pump.
I think my ski hits pretty hard for small stock stroke engine.
just 2 videos to give an idea, and im NO skilled freestyler, got 30 hours total on my engine.
2. if you are tuning in, pump, carbs or engine and are having troubles. write all your settings down with dates and pro/cons. So you can track back problems / gain/loss.
Im running a Dasa SS 850 in a KDX, PFP, dual FS 49 and MSD TL. with a 155 OEM pump and a 7/13 mag prop.
The 155 really gave a boost from the 144pump.
I think my ski hits pretty hard for small stock stroke engine.
just 2 videos to give an idea, and im NO skilled freestyler, got 30 hours total on my engine.
Agree with chadman. Yes, ur pissed that u don't have a insane hit from ur motor, but the guys at PHP are easy going and understanding...especially for someone who's been a paying customer. Contact them immediately. Say u apologize for being emotional with ur comments and get this thing dialed to its fullest. You've made an awesome cake ...ur just refusing to put the icing on it with TL and compression. If you want it to be straight free ride/surf boat then leave it be, but if you want a flat water beast then go get the last component, TL. If u already have the domes to up compression use them and put some VP CHP fuel and a msd TL on this puppy and hold on. I like the ATP TL systems (for convenience) but the MSD gives it the full kick in the nuts you want. I ran CHP in my 8 mil lamey a year or so ago. Its almost like turbo for ur TL. Jetting will be different for sure since its oxygenated...prolly need to fatten up 20-25% for safety but if you want to take that engine to the edge then do it. TL systems aren't inherently prone to failure. The peeps that set them up with shoddy connections and attention to detail cause them to fail. Promise, cuz I've done it myself.
I feel for u. I've been in that spot with billet SS Dasa that required all kinds of messaging to get right. Whatever u do is cool, but don't let stupid pride or embarrassment get in the way if u really want to make this thing perform. PHP guys are great.
I feel for u. I've been in that spot with billet SS Dasa that required all kinds of messaging to get right. Whatever u do is cool, but don't let stupid pride or embarrassment get in the way if u really want to make this thing perform. PHP guys are great.
Last edited:
- Location
- marion ohio
I watched those videos about a week ago. Very impressive. And good idea on keeping records thank you
- Location
- NYC/Long Island
Verifying your timing is probably the best suggestion here.. Especially if you are running an aftermarket CDI. Unfortunately, it's not easy as you need a TDC indicator, a degree wheel and a spare flywheel to cut out a window for the timing light. There is plenty of reasons why you could be lacking in bottom end power. I know it's frustrating; I have been there.
One thing I came across recently on my own personal ski; I was lacking tons of response because one carb had a slight leak from the needle and seat. I only discovered it after the engine came slightly loose and it would vibrate the needle off the seat - making the problem worse.
One thing that concerns me is how low of a pitch your impeller is. Maybe it's the size of the pump that requires such a low pitch, but I think you are going wayyy too far in regards of impeller pitch and exit nozzle diameter. If a lower pitch were so good, then every competitor would be running the lowest pitch possible on their set ups and the absolutely largest exit diameter they could get their hands on.. I don't think that is the case.
I am shocked at how much everyone puts the smallest cone, the largest nozzle and the lowest pitch impeller to get more response. Nothing is free.
Larger nozzle -> Less Velocity, less load on engine, easier to spin
Less pitch -> Less load on the engine, power tapers off top
I think a smaller cone takes up less volume inside the pump and doesnt funnel the water properly to exit nozzle. I think the point of a larger hub impeller and stator section is to take up volume in the pump, increase loads, work more efficiently in less than ideal conditions (it loads up quicker with water after airtime). A smaller cone I think is a oxymoron to a magnum pump. However, it must work for some people because people still use them, I just never understood the point.
Point is, with large nozzle/low pitch prop/small cone you are getting off idle response. But I think your whole set up looses steam where it actually matters. IN THE POWERBAND. There needs to be some kind of balance there.
I am not a professional tuner by any means, my experience is limited compared to some others. (I blow pistons like every other week lol)
There are three things that will get you into that powerband quicker .. Race fuel .. Aggressive ignition timing curve and playing with your water injection screws on the pipe. Tune your pipe by RPM or throttle position. Slowly pull the throttle lever and note where the powerband kicks in. Then play with your injection screws and try and get the powerband to kick in a little sooner.
One thing I came across recently on my own personal ski; I was lacking tons of response because one carb had a slight leak from the needle and seat. I only discovered it after the engine came slightly loose and it would vibrate the needle off the seat - making the problem worse.
One thing that concerns me is how low of a pitch your impeller is. Maybe it's the size of the pump that requires such a low pitch, but I think you are going wayyy too far in regards of impeller pitch and exit nozzle diameter. If a lower pitch were so good, then every competitor would be running the lowest pitch possible on their set ups and the absolutely largest exit diameter they could get their hands on.. I don't think that is the case.
I am shocked at how much everyone puts the smallest cone, the largest nozzle and the lowest pitch impeller to get more response. Nothing is free.
Larger nozzle -> Less Velocity, less load on engine, easier to spin
Less pitch -> Less load on the engine, power tapers off top
I think a smaller cone takes up less volume inside the pump and doesnt funnel the water properly to exit nozzle. I think the point of a larger hub impeller and stator section is to take up volume in the pump, increase loads, work more efficiently in less than ideal conditions (it loads up quicker with water after airtime). A smaller cone I think is a oxymoron to a magnum pump. However, it must work for some people because people still use them, I just never understood the point.
Point is, with large nozzle/low pitch prop/small cone you are getting off idle response. But I think your whole set up looses steam where it actually matters. IN THE POWERBAND. There needs to be some kind of balance there.
I am not a professional tuner by any means, my experience is limited compared to some others. (I blow pistons like every other week lol)
There are three things that will get you into that powerband quicker .. Race fuel .. Aggressive ignition timing curve and playing with your water injection screws on the pipe. Tune your pipe by RPM or throttle position. Slowly pull the throttle lever and note where the powerband kicks in. Then play with your injection screws and try and get the powerband to kick in a little sooner.
Christian_83
Xscream
- Location
- Denmark
Ur welcome, BMW im running 180psi compression and 99oct vpower pumpgas
Whist nozzle diameter Were you running with tre 7/18?
You should really try TL, I felt it was like adding a b pipe to a Stock sj. You should be able to get that thing to rip, and trust me - when it all adds up, you Will be happy. Im still amazed over how my overall package performs now, and i have always been told, that the dasa Ss 850 5port was a very mild Engine with a seroious lack of bottom.
Whist nozzle diameter Were you running with tre 7/18?
You should really try TL, I felt it was like adding a b pipe to a Stock sj. You should be able to get that thing to rip, and trust me - when it all adds up, you Will be happy. Im still amazed over how my overall package performs now, and i have always been told, that the dasa Ss 850 5port was a very mild Engine with a seroious lack of bottom.
- Location
- marion ohio
Well tried out the new ignition curve. To my surprise it definitely helped. Pump was already cavitating and I already knew I would have to change props again but it was nice to see an improvement.
Byeai
"Cheetos-Man"
- Location
- Melbourne FL
Now do total loss and ull get way more power
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Sent from my SAMSUNG-SGH-I337 using Tapatalk
Christian_83
Xscream
- Location
- Denmark
Thats nice! i really think you should consider a TL ignition system, if you haven't given up on skis. It really does adds snappiness to the bottom and throttle response !
chadman154
#Itsonlymoney !!!!!
- Location
- Dirty south
Next step..... verify timing .....
- Location
- marion ohio
Well unfortunately finally having an improvement kinda reinvigorates my willingness to keep going after what I want. Big thanks to the gentleman who will remain nameless unless you feel like taking credit. For all your help should finish of your list in a couple weeks.
- Location
- Harveys Lake PA
Shot in the dark here but all this prop size talk has me wondering how many of you that contributed to this thread believed the numbers on the prop or package vs what they actually measure out to be in a pitch gauge??? I had one brand new from skat that was off by 2 and 3 degrees depending on the blade measured. This was true for leading and trailing edges. It might be worth measuring before chasing issues any further and buying props?
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Sent from my SAMSUNG-SM-G870A using Tapatalk
Thanks for chiming in on that note Brian! Props are always a crapshoot
- Location
- Harveys Lake PA
I always thought the number was the number myself. until an experience with one that was way way out. I just thought it would be a good point to bring up.
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- Location
- Marion, Ohio
We did run into the incorrect prop pitch issue while getting tuned by Phil. I rode the ski today and damn did that ignition curve make a difference! I'm going to drill and tap his manifold for a spray bar and see what that does too.
- Location
- Harveys Lake PA
I heard rumor that putting water in a powerfactor pipe is doing big things.
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- Location
- marion ohio
Wrench prop reinstalled.