Turbo boost quit on 2007 Polaris

[trailshredder]

My Turbo Boost quit on me last year on my last ride in the UP. I know the turbo operates on a vacuum. The turbo spins good so I don't think the turbo itself is bad. Has anyone experienced this problem? If so what did you find wrong?? I spoke with a couple guys who have Polaris four strokes while in the UP last year and they said the same thing happened to them and the dealer had to repair a vacuum line, problem is I am not too sure wich line it is???? Any input would be appreciated. Thank you in advance.

[srt20]

Sounds like the wastegate is stuck open. Not sure how those sleds are designed, but I would assume the wastgate is vacuum operated. So thats the hose I would be checking.

[dofo1]

Have all the updates been done?

These sleds have a lot of problems with wires/ hoses rubbing under the hood.

If the boost reference hose update has not been done start there. Look at the section of hose that runs between the inter-cooler and the alternator, it need to be routed as far away as possible from the turbo because it can be melted by the heat.

Also it is not unusual for the pressure line from the turbo to the boost box to get blown off back by the throttle bodies.

A good place to get info on these sleds is http://www.polarisfiles.com

Also check out the info listed in http://www.polarisfiles.com/forum/in...?showtopic=950

[trailshredder]

Thanks Guys- This will give me somewhere to start anyways. And yes I do believe all updates were done but I will check it out. I bought the sled in January 08 and it hss like 6 update stickers on it.

[lvr1000]

srt20, if he has no boost, the waste gate would be closed if it's a waste gate issue.

Picture of waste gate wide open

[raceinsnow]

First remove the air filter housing and clutch cover and look at the boost reference line(Clear 1/4 hose) that goes from the waste gate(on the side of the intercooler) to the air box(Black box that goes on the throtle body).I would just replace that hose,and make sure that you wrap that hose with some foil tape were it goes by the turbo.(part of the update)

[maxwell]

If the wastegate is open, isn't this allowing everythign to bypass the turbo, so the turbo does not spool up any higher?

[raceinsnow]

OK the the BOV (blow off valve) is next to the intercooler(not the waste gate like I posted before).The waste gate is part of the turbo and that controls the exhaust pressure to spool up the turbo quicker.If the waste gate was stuck open then it would be slower to spool up.The BOV conrtorls the boost pressure to the air box.The BOV is controled by the computer thru the boost referance line.If the computer dosnt see the target boost pressure the computer will put the engine in limp mode and a check engine light will come on.

[trailshredder]

The check engine light is on. It blinks. I have no boost at all. 55 mph at wot. I'll check that line and get back to you.......thank you.

[trailshredder]

I checked the clear lines and they were all good. The aluminum tape had been installed on the one coming from the BOV. I took the lines off and pressure tested all of them. So do you think the BOV is bad??? If so is there any way to test it???

[srt20]

LVR1000, are you sure you dont have it the other way around? At least on every turbo engine Ive had, when you get to a set number of boost the wastegate open to prevent overboosting the engine and streching the headstuds and headgasket. All my experinces are with turbo diesels that boost up to 44psi. Maybe sleds are different with 7 psi of boost?

[trailshredder]

I'm thinking it's the electronc boost control valve. This operates the waste gate and the waste gate is not opening and closing.

[jeff]

I dont have this prob with my 2-stroke.

[mspease]

And you have no idea what it's like to feel the pull of that engine with the turbo! It's amazing. Your 2-stroke will need rebuilding twice before our 4-strokes will the first time. The guy is looking for help, so why make a post like that?

trailshredder,

You probably would have noticed this already, but I had the same problem once going across a lake. It ended up the pipe coming out of the top of the intercooler had come slightly off due to the clamp loosening up.

[jeff]

rode the fst.....raced the fst.....not THAT impressive my 800IQ will take it had 20000 miles on my last 800 never touched! even if I do rebuild it three times still cheaper than one rebuild in a four stroke

[lukester]

You have 20000 miles on any 2 stroke and its still running ??..Then alone running strong.
If that's even close to being true Id like to take you to VEGAS with me.
Although that appears to be very unlikely, If in fact you do have 20000 miles on a 2 stroke you already paid for a complete rebuild/replacement in gas mileage and SYN oil alone not to mention hours upon hours of lost riding time spent hunting down gas/oil stops. And dry cleaning bills. LOL.
In a earlier post you state
"I don't have that problem with my 2 stroke"
OK.. follow me 100 miles into the deep woods. Lets see who has the problems getting home.
I,... along with others on this sight ride with 2 strokes. We all know the "extras" involved.


You also state that you "raced one..Not THAT impressive"... OK ??... You still lost!!
And if by some quirk you stayed along side ...don't try it again. You got lucky there sport.

[lukester]

trailshredder,

As posted above its almost always a simple fix.

mspeace's suggestion is right on. a simple hose clamp can (and often is) the whole problem.

Look it over carefully. Get a understanding how the whole thing fits together.
Once you get a general understanding it all makes sense.

PS: check the (clear) "vacuum hose" forward of engine.( easy to see by just opening hood)
It may be sucking closed when vacuum is applied >AFTER< engine is warm. It may look fine when engine is cold.. LOOK CLOSELY!!
Most often its just that simple.

[jeff]

I havent lost to a four stroke yet....But there is always a first

[lukester]

Yes you have.
And the same thing will happen next time.
It crystal clear that you had your ••• handed to you by a FST...More then once.
You wouldn't be here posting unless that was true.
You simply wouldn't care.. Unless you lost.

[jeff]

SORRY...BUT NO I tell no lies. Cause we all know that eventually they WILL catch up with you! You kids just cant handle that there are people out there that have different opionons and experiences other than yours. I thought this site was different HCS. A little friendly jousting goes too far when someone cant take a little critisizm. You like what you like and I what I. maybe some day we can get together,line em up and when its all done with; have a beer and talk about the whole thing.Unless your a tit for tat (my stuffs always gonna be better)kinda person.Hope to see ya all on the trail.

[lukester]

A little friendly criticism is one thing.
I've seen your past posts.
In them you have been quick to rip on FSTs for some strange reason?
That being said ..One would have to ask... why?
Often the answer is simple.

Hey,if your ever in the Tomahawk/Mina/Willow area and you want to see what a properly set up >STOCK< FST can do.Id like to show you something.
If your interested .Ill buy the beer. You can tell me what you think. Friendly enough?.. Hey its all in fun.

OK, back to the subject. the post is supposed to be
TURBO BOOST QUIT ON 2007 POLARIS

[jeff]

you buy the beer Ill be there!

[lvr1000]

maxwell & srt20, I stand corrected, you are right, I do have it backwards. 22 years I've owed a turbo and always thought that when the gate opened, it allowed more exhaust gases to spin the turbine. So when I rechipped and shorten the control arm, I was actually closing the gate quicker instead of opening quicker. 22lbs of boost w/ 110 octane on the car and 12lbs w/ 91 octane on the sled

[lvr1000]

I do like the hose clamp suggestion. When I first ran at 22lbs of boost, I blew the hose right off the turbo. Noticed immediately, I came up out of the seat (g-force) and very loud whistle. I replaced with aftermarket hose clamps.

[lvr1000]

I do like the hose clamp suggestion. When I first ran at 22lbs of boost, I blew the hose right off the turbo. Noticed immediately, I came up out of the seat (g-force) and very loud whistle. I replaced with aftermarket hose clamps.