[STEVEJR]

I just did a top end rebuild on an 06 firecat. Started it many times in the shop, got the coolant level all good, started many times, just sits there idles perfectly, starts first pull, thought the pto piston went down from crappy fuel, cleaned the tank all out lots of water and crap. Just scared of a possible crank seal or smart valve problem, I just can't wrap my head around a possible smart valve failure and burn down, shouldn't it just run out of fuel if the valve closes, 12,000 miles on this sled,I did a rebuild at 7000, just because. The mileage scares me about crank seal? Someone adjust my brain on the smart valve. I own five firecats and never an issue with that valve

 

[stronger800]

I never thought about them either. Isn't there two? They'd both have to be stuck closed before it starved for fuel, and like your saying, it should just run out of fuel. Not go lean.
Man I always like that 900 pic. Still have it?

 

[STEVEJR]

Yes I still have the 900, I just keep reading where people think the one smart valve stuck and they think it leaned the PTO side , yes it does have 2. This sled was a friends, I have always maintained it, it's in awesome shape so bought it cheap, when I got it he never gave me the piston that torched so I have nothing to go by, all I know is he took it out of storage did one lap and torched the pto side, I rebuilt it, had a set of redone cylinders and there it sits idling perfectly

 

[STEVEJR]

Well finally tried to do a lap around the field after many start ups and warm ups just at an idle, took it for a lap and did not make it back scarred the hell out of pto side piston and cylinder again, didn't even go over 4000 rpms, what a bitch, rebuilt with ultra care,reached right in the tank with brand new fuel and the one smart valve totally sucked in, I can't believe it

 

[zr8rider]

Last year both smart valves in my f7?we sticking. Rode it over a thousand miles yntil I figured out what was wrong. Fixed them with bic pen springs. This sled was fuel starved half the winter with no melt down or other problems

 

[STEVEJR]

Yeah,,, I think its crank seal,its very high mileage, I have another complete motor to put in and I will be doing the pen spring fix on the smart valves

 

[STEVEJR]

Ended up swapping a 04 700 motor into the sled, new water pump shaft and seals, new pistons rings wrist pin bearings, renic cylinders top end gaskets orings, pulled the stator and flywheel,wash is good nice looking plugs. Did the pencil spring swap for the smart valves, if you use the pencils instead of the pens the spring is perfect length just a little beefier. So it was probably a combination crank seal and smart valve lean out, which would account for pto side heat

 

[STEVEJR]

Also those smart valves may not look dirty, just spray some brake clean on them and watch them clean up and turn white again, that's a pretty fine screen