Freestyle Bog after second or third trick

[maxsimoneau]

I sometimes get a "bog" after the second or third tricks on my revolver with a dasa 1200.
It does not happen all the times .
What do you think it could be ?
Too much fuel ? Not enough??
Please watch this video:

 

[Sparkplug]

Man wtf

 

[RiverRides]

Lean bog?

 

[maxsimoneau]

Man wtf

?

 

[DylanS]

Does this happen if you just throw continuous flat spins?
If you ride the ski flat and just whack the throttle and jump a few times in a row do you have the same issue?

 

[mthomps]

Its probably the tall drink of water the ski just took

 

[maxsimoneau]

Does this happen if you just throw continuous flat spins?
If you ride the ski flat and just whack the throttle and jump a few times in a row do you have the same issue?

it sometimes happen with flat spins but not as often

Its probably the tall drink of water the ski just took

yeah maybe ..

I will need to find if it is caused by a lack of fuel or water ingestion .

 

[Rushford_Ripper]

Try upping the jets a size and see if the issue goes away.

 

[DylanS]

Do you have this issue on a mostly full tank?
Could be fuel pickups coming out of the fuel momentarily.
To me it doesn’t seem like you ate that much water during that ordeal but I obviously have no clue on what’s already inside your bay.

Im having trouble telling if it sounds lean or rich on that last flip.
If it was THAT lean under that much load I’d say the ski would just about shut off on you. I’d say it sounds loaded up more than anything the entire time you’re riding it.

you could possibly be experiencing a rich
condition when you are letting off the throttle after a hard pull due to low pop off pressure. Raw Fuel could be laying on top of your plates and when you go to grab that flip you’re just dumping it down the barrels.

What oil do you run? Do you have milky white residue in your carbs/on your air cleaners after you have this issue?

 

[hornedogg79]

Any premix residue on your hood liner? I've had this same issue and ended up increasing my pop off and pilot jet size. Also got rid of pod filters with mesh that tend to hold water or fuel.

 

[mthomps]

Did it always do this

 

[maxsimoneau]

Do you have this issue on a mostly full tank?
Could be fuel pickups coming out of the fuel momentarily.
To me it doesn’t seem like you ate that much water during that ordeal but I obviously have no clue on what’s already inside your bay.

Im having trouble telling if it sounds lean or rich on that last flip.
If it was THAT lean under that much load I’d say the ski would just about shut off on you. I’d say it sounds loaded up more than anything the entire time you’re riding it.

you could possibly be experiencing a rich
condition when you are letting off the throttle after a hard pull due to low pop off pressure. Raw Fuel could be laying on top of your plates and when you go to grab that flip you’re just dumping it down the barrels.

What oil do you run? Do you have milky white residue in your carbs/on your air cleaners after you have this issue?

I am runinng amsoil dominator 50/1 with 75%avgas and 25% 91pump. And yes I do have milky white residu on my flame arrestors after the issue.

Did it always do this

Well this is a new engine/pipe combo for me this year. So yes

I will get back on the water and do some tests this weekend.

 

[DylanS]

If you have residue with dominator you’re probably seeing some water ingestion and you’re probably rich right off the bottom. I’d say you’re loading up after letting off the throttle.
If possible strap your ski down in the water and run it with the FA’s off. If you can’t just do it on land. If you’re shaking fuel out of your venturi you have an issue and it’s going to really rear its head when you let off the throttle after a hard pull.

Post up some specs then, I’m running a similar setup.

 

[maxsimoneau]

If you have residue with dominator you’re probably seeing some water ingestion and you’re probably rich right off the bottom. I’d say you’re loading up after letting off the throttle.
If possible strap your ski down in the water and run it with the FA’s off. If you can’t just do it on land. If you’re shaking fuel out of your venturi you have an issue and it’s going to really rear its head when you let off the throttle after a hard pull.

Post up some specs then, I’m running a similar setup.

5 port dasa 1200cc 210 psi, bun pipe, 62T zeel,
ET 52mm carbs
145 low
135 high
25 psi pop off
60 return jet

 

[DylanS]

Did you by chance go to the gp800 style kidney block or double up your check valves? With a 60 at 25 on that engine you’ll for sure be having fuel shake out of those carbs.
My info is as follows and I ride in pa so take this for what you will;

FS 50’s:
Main 132.5
Pilot 122.5
Pop off 24psi
Pro-k filters
60 return
I am running 800 blocks and doubled check valves to combat the high fuel pressure and low pop off.

This is on a 5 port with a rrp carbon chamber and total loss spinning a 13/19 in a 155 setback mag.

I’d say from listening to the ski it sounds rich on the bottom and you’re just getting loaded up.

 

[fastgtfairlane]

Adjust your fuel pressure. I bet that is part of your issue. You'll probably end up with a 80 to 90 main jet in the return to get your fuel pressure to 1-2psi at idle and 4-5psi at wot. As stated earlier, it does sound a little rich to me on that 3rd trick. If it was lean, it would've most likely died. I had some strange fuel issues with my built 735 with dual 44s that had the returns drilled out. Went from a 70 to 85 jet in the return and it was night and day difference. Yours being a stroker and much larger bore will just amplify the issue. Too high of fuel pressure is similar to too low of popoff. It'll cause fuel to dribble past the venturis while riding that will cause random rich bogs that clear out after a few quick throttle blips. Lowering the fuel pressure cured the dribble.