Freestyle Jetmaniac ported 701 - 210PSI - too much for regular pump gas? (PROBLEM SOLVED)

[Waldbjoern]

As the title explains i have a 701, 62 cases with 61 x cylinder, freestyle ported by Jetmaniac. Its sporting a b-pipe and 38mm Mikuni's. It measures over 200 PSI on each piston.. Is that too much for regular pump gas?
Ive bin experiencing a few problems with it lately. Its like it hits a rev limiter, like it doesn't get enough gas.. I am sure the carbs are all right, since they were just rebuild and re jetted. All electrics has bin checked and works fine! Its running a EPIC ES ignition module..

Any thoughts?

Cheers

 

[stefan]

Blue does make a specil porting on hes cylinder and squish that was ment too run High comp on pump gas Think hee ran 235 psi on hees ovne engine.

 

[Waldbjoern]

Hmm, so i shouldn't think about re doming to a lower cc just jet?

 

[Berky]

If you're hitting the rev limiter riding you are sucking air at the pump or you need a taller prop (good thing) . Make sure Fuel filter are in good shape, tank check valve is working and tank develops pressure or you won't get enough go go juice .

 

[Waldbjoern]

Well I am not hitting the actual rev limiter - it just sounds like the rev limiter - but way quicker buzz if you know what I mean. Thats also why i thought it would be electrical. Coil and CDI as both bin changed and no difference. Also a few small leaks were found at the manifold to the pipe - thats also bin fixed..

After the carbs were taken apart last, i found a flaw in the return line that was clocked up. After cleaning the hole and putting them back together, the BOB ran smooth again, but only for like 10 minutes .

Then the problem was back, and for every minute its used it gets worse and worse..

Cant think of what the problem might be!!

 

[JetManiac]

For freestyle type of riding 210psi on our (US) prem pump gas works well. This means no sustained wide open type of riding. My own ski has 215psi for last 1 1/2 of hard riding on prem pump gas.

Would need more info to help with your running issues.

 

[Harbor]

So you removed the epic CID and installed a different CDi and retested and it still acted the same right? I hear a lot of horror stories about the epic CID that's why Iam asking for clarity on that part. So i just went thru a sorta simallier issue, I was running none resistor spark plugs and after a little riding the engine would not rev fully, like I was hitting a rev limiter, and the more I rode it the worse it got. Turned out the none resistor spark plugs produced RFI (radio frequency interference) and that interference was talking to my Cdi and causing internal electrical disruption/confusion of the Cdi electrics. Took awhile to get figured out but replace spark plugs from bp8es to bpr8es fixed the problem.

 

[Waldbjoern]

I ride with resistor spark plugs, and have tried different sets to rule it out. I know of that issue.

Ive tried with EPIC ES and stock CDI, and both act the same..

Well as long as 215 PSI on the cylinder is not the problem ill have to believe that the problem is within the fuel system..

The fuel pump is up to date, and so is the filter. Also the cart tank has bin tested if the valve works..

 

[tor*p*do]

what kind of Euro fuel are you using?

 

[Waldbjoern]

In denmark we have octane 92, 95 and 98 (98 is rare). I always use octane 95 with 2% mix of oil.

 

[Fro Diesel]

In denmark we have octane 92, 95 and 98 (98 is rare). I always use octane 95 with 2% mix of oil.

That sounds perfect for that motor. Should make great power.

Does this ski have side exhaust?

sent from Fro Diesel using tapatalk2

 

[Waldbjoern]

Nope - no side exhaust!

 

[MADMAT]

Man I can feel when that gas tank check valve is bad! Yet I have heard others say they couldn't tell or ever more weird ...it got better!

When mine falls off I can tell right away...I still have all my low snap but as soon as I get on it it falls. Mine is on with cclamps and a safety now....it fell off and got in my 1 way pump dump valve twice

 

[Christian_83]

I would reccomend running 99 Vpower any day, just to be on the safe side.
Does it loose its power? Could it be knocking or detonation?

 

[Matt_E]

That sounds perfect for that motor. Should make great power.

Does this ski have side exhaust?

sent from Fro Diesel using tapatalk2

Realize that European octane ratings are different (higher) than US octane ratings.

So European 92, 95, and 98 probably correspond to 87-89, 89-91, 92-94 in the US, respectively.

 

[Waldbjoern]

Well i don't know how to explain it better than its like its hits a point when i cant rev higher, and it looses its ability to preform. It sounds like a rev limiter, except the sound is quicker.. Its like it doesn't get enough fuel. Although springs, needle, seat and jets are all correct - its even double checked!

As allready explained after taking the carbs apart for the second time it ran like a dream for 10 minutes, and then it started to act all weird again.. The longer you rode it, the worse it got!

 

[grahammy]

Then the problem was back, and for every minute its used it gets worse and worse..

Cant think of what the problem might be!!

Sounds like an exhaust gas leak

 

[Waldbjoern]

Ive checked the exhaust more than twice! I found a few VERY small leaks, that are sealed and checked! No leaks on the exhaust for sure!

 

[Christian_83]

Exactly Matt, thats why im only running Shell V power (octance 99/100) http://en.wikipedia.org/wiki/Octane_rating
Can you get the engine/ski to rev higher, when only opening the throttle 30% or will it still "buzz"
whats the carb settings ?

 

[Waldbjoern]

Main Jet : 145
Pilot Jet : 120
High speed screw : about 1 n a half turns out from closed
Low speed screw : about 1 n a half turns out from closed
Needle & Seat : Stock
Spring 95 grams

Hmm, might wanna try with the shell V-power !

When going up slowly and not putting too much resistance on the engine/prop, then you can make it go faster! Its when the engine has to work hard that it gives up!