Engine-Tech 900 BIG BORE (polaris edge)

[lyspera]

Hello, anyone have experience with engine-tech 900 big bore kit. Had a little trouble last season, after long WOT pulls i lost 300-400rpm ish but if i let off the gas a little it would wake up again. I suspect too tight outlet in pipe (stinger)?

Sled is equipped with SLP singel pipe (800pipe), oem ignition, jetting was pretty spot on.

Any suggestions on this one?

Feel free to share other experiences with this engine package!

 

[kanedog]

The secondary clutch is not backshifting. The secondary is dirty and needs a new spring and buttons(maybe rollers depending on clutch).
Clean and rebuild secondary.
Ride it like you stole it!

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[BILTIT]

Personally i think anything in the 900 range should have twin pipes, any single on the market just doesnt flow enough. Carls 910 only came with twins as far as i know, for that reason.

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[lyspera]

The secondary clutch is not backshifting. The secondary is dirty and needs a new spring and buttons(maybe rollers depending on clutch).
Clean and rebuild secondary.
Ride it like you stole it!

Sent from my SM-G920W8 using Tapatalk

I have a team tss-04 clutch, spring is in good condition, the rollers also.

 

[lyspera]

Personally i think anything in the 900 range should have twin pipes, any single on the market just doesnt flow enough. Carls 910 only came with twins as far as i know, for that reason.

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What kind of twin pipes is easy to tune and reliable for mountainriding for the 900 package?

What about welding on a larger outlet on the SLP singel pipe?

 

[BILTIT]

I have had my 910 in two different edge chassis with slp twins, 03 rmk 162" and an 04 proxr 121". Put in a holtzman atacc and dont have to tune a thing once the initial setup is figured out.

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[lyspera]

I have had my 910 in two different edge chassis with slp twins, 03 rmk 162" and an 04 proxr 121". Put in a holtzman atacc and dont have to tune a thing once the initial setup is figured out.

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Hmm.. Maybe i need to try out twins on it!

 

[kanedog]

Has it always worked or did it just start having this issue?

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[lyspera]

Has it always worked or did it just start having this issue?

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Installed the 900 for the first time this spring, and it always lost rpm after long pulls. but with shorter pulls it ran like a monster.

 

[kanedog]

What rpm is wfo on a short pull and what is rpm on a long pull when it loses rpm?

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[lyspera]

What rpm is wfo on a short pull and what is rpm on a long pull when it loses rpm?

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8200ish on short pull
7700ish on long pull

 

[kanedog]

Assuming clutches are clean/rebuilt and a new belt-
Add 20lbs to the end number of the primary spring.
Example-if you have a 140lb/280lb
Spring, go to a 140/300 spring.
If the sled holds rpm but not quite the 8200, go to the next size up like a 140/310 and so on until you are happy with it.



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[lyspera]

Assuming clutches are clean/rebuilt and a new belt-
Add 20lbs to the end number of the primary spring.
Example-if you have a 140lb/280lb
Spring, go to a 140/300 spring.
If the sled holds rpm but not quite the 8200, go to the next size up like a 140/310 and so on until you are happy with it.



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I currently run SLP 160/340 (green/pink)

The sled holds 8200+ good on shorter pulls, only on really long wot i get a drop in the rpm.

 

[kanedog]

Hmmm. I wouldn't recommend going heavier spring with this one being 340lbs.
I can't come up with anything except maybe the primary spring is sacked.
Sorry I couldn't help.


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[BILTIT]

I can look at my clutching book later tonight and give you my setup but i run a team tied so abit different.

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[05rmksteve]

Possibly running rich at wot and cooling the pipe or to much air/snow getting to the pipe and cooling it.
I was going to try a slp single for ported motors with my carls 910 but I talked to Carl's about it and they told me the 910 was designed to run with twin pipes so I never tried the single.

 

[BILTIT]

What jetting are you using and at what altitude?

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[sno*jet]

just a hunch, kanedog was on to something, backshift. this will happen on short vs. long pulls. I went back to stock button secondary specifically for this reason on my 02. the helix in my team was a tad too much and the button was free and much more consistent off trail.

 

[lyspera]

What jetting are you using and at what altitude?

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ran with #420 main and needle jet in groove 2. Riding at sealevel to 1600ft

 

[lyspera]

Possibly running rich at wot and cooling the pipe or to much air/snow getting to the pipe and cooling it.
I was going to try a slp single for ported motors with my carls 910 but I talked to Carl's about it and they told me the 910 was designed to run with twin pipes so I never tried the single.

Could be, but i have a Engine-tech 900 motor and it is designed to run botn twin and single.