Full spectrum setup problems

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geraban19

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Guys,

I need some help on a new set up on a new motor that i'm building. It's a RIVA flat top cynlinder 85mm r&d style pistons, ada head w/28CC domes, 185 psi compression, msd enhancer, FPP B and a complete 48 full spretrum intake system.

The ski seems to be always reach around low-mid range. The exhaust outlet is very dark.

I talked to Ed and he told me to go 132.5 main, 122.5 pilot and 25 psi pop off. Since Ed is an specialist I doubt it needs a smaller pilot jet. Mid-to-high is pretty good.

Since the cylinder was race designed i think it may has some issue.

Any input is welcome.

Thanks

Gera
 
Prem1x

Prem1x

Tinkering obsessed
Location
Austin, TX
That should be real close. I started there and had a lean hesitation with a similar setup (minus the flat-tops). I had to lower the pop-off. Try raising yours.
 
Flash-FX

Flash-FX

No Square..No Round..FX-1
Location
South Jersey Shore
Been there...It didn't work. Ended up with 17psi pop. and L/s adjuster set at about 1/4 turn out. I could never get it to run at the suggested settings.:aargh4::aargh4::aargh4::aargh4::aargh4::aargh4::aargh4:
 
G

geraban19

X
Flash-FX said:
Been there...It didn't work. Ended up with 17psi pop. and L/s adjuster set at about 1/4 turn out. I could never get it to run at the suggested settings.:aargh4::aargh4::aargh4::aargh4::aargh4::aargh4::aargh4:
Click to expand...

Are U talking about Ed Brazina's tips???

Well, to tell U the thruth I had the same problems always but I know people are happy with him at all.

I will try to close low speed adjuster and raise pop off to 28psi.

tks

Gera
 
the only couch rider

the only couch rider

Location
Jersey
depending on how the porting was set-up it could be a top end race port low end is good for a tight course but if you are always racing a course that has a long start or straight aways you probably want the top end porting.

this is just a guess on my part.

ed's specs are spot on. the only time you really should have an issue with his carbs are if you change something on the motor and try to make the adjustments yourself.. that is really the only time i heard of people having issues with his carbs aside from buying a used set and trying to get them set up on your own.
 
SUPERTUNE

SUPERTUNE

Race Gas Rules
Location
Clearwater Fl.
The giveaway is in the question...I'm running 28 cc domes and have 185 lbs of cranking pressure on a flattop piston set-up. A rec/freestlye engine porting would have about 195-200 lbs cranking. Overported exhaust/transfers ports designed for top end will create overrich bottom end conditions. Exhaust system restrictions will also greatly affect carburetion too.
 
Flash-FX

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No Square..No Round..FX-1
Location
South Jersey Shore
Ed's a great guy,He answered all of my questions and more. The motor I bought "assembled" (not from Ed)was supposed to have been "test ran and set up". I believe it was not, because it came with 23psi pop 122.5 l and 135 H. I tried to get it to run with those settings but the low speed (pop-off)was too lean. In order to make it run the L/S screw had to be out more than it should. Every time you would let off the gas, raw fuel would dump into the exhaust system...LOTS of black crap pouring out of the pipe. After some phone calls, I decided to "go with what the motor" needed. These carbs are real sensitive to low speed adjustments. Mid and high speed is not a problem, they draw enough fuel to run wide open for extended time.
The motor they came on was a stock stroke 85mm Lamey,180psi,flat tops. That setup liked 16.5-17psi pop off. After some issues with the cylinder, I installed a ported 61x top end on that bottom end. The 61x liked 12psi pop-off.
 
waterfreak

waterfreak

I had a vision!
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Location
s florida
Have you checked your squish? A good freestyle set up would be around .040
that might also explain your compression ratio.
 
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No Square..No Round..FX-1
Location
South Jersey Shore
waterfreak said:
Have you checked your squish? A good freestyle set up would be around .040
that might also explain your compression ratio.
Click to expand...

Not to threadjack but...Funny you asked...In my case the squish ended up @.060...Not my choice. It's the maximum Jennings recommends in his 2 stroke handbook, from like 1972. I'm still learning...$$$

I'm Not going to open another "can O worms". :grumble:

Besides milling the deck, what would you guys recommend the best way to reduce the "squish" for flattops?
 
G

geraban19

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waterfreak said:
Have you checked your squish? A good freestyle set up would be around .040
that might also explain your compression ratio.
Click to expand...

Thanks Steve but my concern is about the rich condition not the poor low end.... even if it is poor in power it can't be so rich.

I realized the return jet clogged but I think that also there's too much water in the exhaust... The ski is too quiet and it spills too much water after a good run.

Gera
 
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Cross

Cross

X
Location
WA
Flash-FX said:
Not to threadjack but...Funny you asked...In my case the squish ended up @.060...Not my choice. It's the maximum Jennings recommends in his 2 stroke handbook, from like 1972. I'm still learning...$$$

I'm Not going to open another "can O worms". :grumble:

Besides milling the deck, what would you guys recommend the best way to reduce the "squish" for flattops?
Click to expand...

Run a thinner base gasket.
 
SUPERTUNE

SUPERTUNE

Race Gas Rules
Location
Clearwater Fl.
Mill the cylinder is the best way...if and or you use an ADA head you can skim the squish IF it's too tight. If motor is ported and want a little more bottom end power, a thinner base gasket will help with both.
 
Flash-FX

Flash-FX

No Square..No Round..FX-1
Location
South Jersey Shore
Gera, Please post your jetting/pop-off outcome when things get worked out. I'd like to see how close they were to mine. There was times I thought I was crazy :thinking:because everybody runs about 23psi pop-off on their boats (w/Full Specs). My boat has no more :nono:goo running out the pipe :arms:.

Cross,Chuck...Thanks for the base gasket tip. :fing02:
 
G

geraban19

X
SUPERTUNE said:
The giveaway is in the question...I'm running 28 cc domes and have 185 lbs of cranking pressure on a flattop piston set-up. A rec/freestlye engine porting would have about 195-200 lbs cranking. Overported exhaust/transfers ports designed for top end will create overrich bottom end conditions. Exhaust system restrictions will also greatly affect carburetion too.
Click to expand...

Supertune.... U are the winner.

EXHAUST RESTRICTION is the problem.

I just got a used "like new" waterbox from Ebay and after inspect it yesterday I realized that the guy welded a piece of a tube in the waterbox inlet to quiet the sound of the ski (I guess so).

After switch it by another one the ski was near to perfect.

Flash-FX.
The jetting is like we talked before:
Main: 132.5
High adjust: 1 turn
Pilot: 120 (I think now it needs 122.5)
Low adjust: 1 turn (My mechanic adjust one of the carbs a little less)
Pop off: 25psi
Needle/seat: 1.8
Spring: black

I will do some other adjusts but the ski is very good for surf or freestyle pump gas.
The pipe is too cold yet. Even with mid and top screws closed and the bottom one open just 1/4 turn it is still not that hot because I am running dual cooling and have only 2 bypass fittings getting water out of ski.

Since LEGDRAG was out of stock of their MAGNUM 144mm PROP I am running a SOLAS I.... not good for the ski.

I am sure that with a freeride prop and some play with water lines, another bypass fitting and a flow valve, the ski will be top notch.

So... the FULL SPECTRUM (Ed's) settings are pretty close to the reality.

Thanks all U guys.

Gera
 
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