Jetting for high attitude Blaster

[Quinc]

I am running a 170 main in my blaster and running 6650 - 6750rpms with a heavily modified engine.(build is in my sig)

OP - if the duo engine is straight out of the duo and dropped into the blaster with no other mods done to it you can probably leave the jetting alone, or go up one jet size just to be safe. Best way to know would be to invest in a tachometer.

 

[98yota]

The Kraze's came with the Westcoast pipe (well it's made by them with the WetJet emblem cast on instead) and the Mikuni SBN46. Only some came with the Westcoast high compression head but the Wetjet parts website only lists one set of jetting specs. Would the change in compression from 140 (I think that's the stock psi) to 170ish warrant a change in jetting?

 

[RMBC Freeride]

^^^ No, generally not. Especially since you are going up in elevation.

 

[98yota]

Well the good news is I took some time and made a bracket to relocate the Ebox and it works great! I got the thing completely reassembled, plugged the lanyard in for a quick test fire, pushed the starter button and the engine started right up! Great!!! Now the problem was, the starter motor was still cranking as well!!! I shut the motor down and the starter motor was still turning! I disconnected the battery and finally got it to stop turning. A few months ago my original starter soliniod became intermittent so I replaced it with this one. Apparently I received a defective one. Sooo the Ebox is back out of the boat with all of its gut out yet again! I sure am glad this didn't happen on the water! Luckily I ran some tests and found the starter and other electronics were unharmed. Another positive is my new bracket makes getting the Ebox out much easier!!! Here are a few pictures of the bracket and mounted Ebox (prior to the previously described fiasco!)

 

[98yota]

Well I replaced the defective starter solenoid and I'm back up and running! Tomorrow I'm going to throw on the new carb and manifold and start tuning!

 

[orangefinger]

We have run all our skis at altitude 4500-5500 best results had always been with 1.5 NS , and recommended jetting increased 5-10 size 130 Main now 135-140 main and so on....raise the compression a bunch and get a flame arrestor that allows for more airflow.