Polaris 90 in the Polaris dealer shop due to sputtering and dyeing when the throttle is applied, it idles fine. This happened abruptly when one of my kids was riding it. Dealer did a compression check based on their call to Polaris headquarters for advice. Compression came back at 5.


It seems to be acting very similar to the way it was 2 years ago. At that time they had to replace the CDI ignition and it worked fine. And two years ago they had no way of checking the CDI without just trying to replace it, but that was what Polaris headquarters recommended at that time so they replaced it and it ran fine.


So they say now that all the electronics checked out fine, but two years ago they said they had to replace the CDI before knowing if that was it.


My question is, could a faulty CDI ignition module cause low compression? I already have $300 in just their diagnostics.

 

No...and I don't think the compression reading was 5psi and still running. Regardless, a low compression engine can run and idle, but often spit & die when load is placed on it...


Have them check the spark arrestor screen...reading it can get clogged and cause poor performance...