2000 indy wont start, low compression, worth rebuild?

[jonesin]

So you have full power range once you get it moving?

Yep!
It lags when I pin it but when it catches up it revs right up and accelerates great
I was thinking of pulling my clutches and checking them out also
The primary was replaced with a used clutch in great shape a few years ago and the rollers and weights still look good from what I can see on the sled
It ran like pretty good like this a few days ago after I put it back together when I found the piece of crap in the carb (turned out to be the needle tip) but then ran worse after taking the carbs apart again and replaced the needles and seats
I am hoping that it is something in the fine tuning of the carbs, adjusting the float level or something, just weird that it goes from bad to good to bad to good, could be something that I am doing I guess....
It still wouldnt explain the not idling down after running it but at least its getting closer to the normal excelent running and dependable machine that it has been for the last 16 years!

 

[lak7]

It still wouldnt explain the not idling down after running it but at least its getting closer to the normal excelent running and dependable machine that it has been for the last 16 years!

Poor carb adjustment can cause the High Idle hang, also a cold engine, and leaking Carb boots.
My triples did that, so I replaced the Carb boots, cleaned / tuned / synced Carbs, now they only hang once in a while, until they are warmed up.

 

[jonesin]

Poor carb adjustment can cause the High Idle hang, also a cold engine, and leaking Carb boots.
My triples did that, so I replaced the Carb boots, cleaned / tuned / synced Carbs, now they only hang once in a while, until they are warmed up.

I
would be thrilled it that is all it is!
I was told it was probably a crank seal but I sprayed starter fluid around all the boots and seals except the one behind the recoil housing I couldnt get to with no change in idle
Getting closer I hope!

 

[jonesin]

it almost seems like when you punch it that it starts to jump out (maybe when the primary clutch first grabs the belt) then the acceleration is slow for 2-3 seconds (trying to get the rpms up while secondary clutch is starting to open) then it takes off and is fine....
I am just guessing that if its not the carb tuning maybe the shaft on the secondary is wore out and is rough and sticking... I had them go bad on the F7 a couple times....

 

[mezz]

Ramps on the secondary are probably worn. I would also check the rollers, weights & pins on the primary.-Mezz

 

[jonesin]

It looks like the weight on the primary r starting to hit the sides of the spider, I need to get the tool to get it out, I only have the arctic cat one...

still doesnt explain the idle keep going up to three thousand...
can j pull the motor and turn it over to replace crank seals without taking the top end apart?

 

[dofo1]

If you activate the enrichers for a second does the idle come down and stay down? If so it's pretty normal on Polaris sleds of that year, you can try adjusting the mixture and/or changing the pilot jet. But make sure that your clutches are serviced and that you have the correct belt listed for your machine.

 

[mezz]

I think you'll find the idle will be consistent once you take care of the clutches. Be sure to service both the primary & secondary that should answer your issue with your acceleration on launch.-Mezz

 

[Rubi]

It's been a few years since I worked on a carbed sled, so I might not remember all the terminology, but here's what I think you've got going on. If you're hanging a high idle, you're lean on the low end. When you crack the throttle, you're probably getting a lean bog until you get into the main jet's RPM range. A way to test this theory is to apply the choke when you usually get the bog. If the choke helps the problem, you are getting a lean bog. The pilot jets on that sled are tiny. They need to be absolutely clean! If the pilots are plugged, you will get a lean bog that clears up once you get to the mid and high RPM range. If those are roundslide carbs, I think the adjustment screws are air screws. Turning the airscrews in will richen the mixture on the low end. If turning the screws in helps the problem, that is more evidence supporting the lean theory. You might end up needing the next size larger pilot jet. The older sleds were not jetted for modern oxygenated fuel. You need richer jetting to make the proper air/fuel mixture with ethanol compared to pure gasoline. If all tests are indicating a lean bog, raising your needles may help your situation also. Drop the clips one ring and see if that helps the transition from idle to full throttle.

 

[jonesin]

are you able to pull the motor and take the bottom off to do the crank seals without disturbing the top end?

long story short:
it started to idle high last year, even if I hit the choke it would idle up
it was running on one cylinder (cdi cable was rubbing on pull chord) - fixed
wouldnt start (needle tip broke off and allowed cylinder to fill with fuel) - fixed

now I found the primary clutch spider is in rough shape from weights rubbing and am fixing that but..

what I am wondering is with it all tore apart I am 4 bolts and disconnecting the coolant away from pulling the motor, thinking that if I could just turn it over to do the seals it would be cheap and peace of mind to check that off my list of possible problems.....
How do you pressure check the engine as discussed on 2001 indy 500 crazy spark thread?
Thanks!

 

[doodad]

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
How do you pressure check the engine as discussed on 2001 indy 500 crazy spark thread




http://www.klemmvintage.com/airleaks.htm

 

[jonesin]

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
How do you pressure check the engine as discussed on 2001 indy 500 crazy spark thread




http://www.klemmvintage.com/airleaks.htm

Wow!
I might have to look up one of those plugs !
I wonder how many people EVER do that?
Thanks!
I put everything back on last night that I had ready and I am hopefully putting the primary back together tonight and going for a run in the mud, we will see what happens..

 

[jonesin]

Not
Sure what happened wrote a reply and it dissapeared
anyway I adjusted carbs again, changed to old belt and adjusted secondary clutch and it is starting to jump when nailed from a stop so I am really getting close
thanks for the ideas and sharing the knowledge!
ledge!