Balmar Serpentine kit fail.

Apr 5, 2009
3,131
Catalina '88 C30 tr/bs Oak Harbor, WA
I bought the Balmar 48-USP-M25 for my M25XP. This should be an easy bolt-on process except that they either sent me the wrong part or then cannot read a micrometer. The pulley on the XP is 130mmø and the drive pulley that they sent me has an OD of 128mm. A 2mm error [64-thousants] in a precision machined part is huge. That is bigger than the spark plug gap on my high-energy ignition system. :banghead::banghead::banghead:
 
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Likes: jssailem
May 1, 2011
5,015
Pearson 37 Lusby MD
Sorry to hear of your woes. I hope the seller will correct the issue for you expeditiously.
 
Apr 5, 2009
3,131
Catalina '88 C30 tr/bs Oak Harbor, WA
Sorry to hear of your woes. I hope the seller will correct the issue for you expeditiously.
Me too!. My daughter and her family are flying in from Arizona in a couple of weeks for a cruise and I need to get the alternator working by then!
 

jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
23,141
CAL 35 Cruiser #21 moored EVERETT WA
Is that the OD of the pulley or the bed in which the belt rides? While the unit is not to spec, what does this affect? Is the belt too long? They use a belt tensioner. Does it not maintain tension on the belt? Is the alternator spinning at a lower RPM?

I suspect they never imagined you would inspect their machining.
 
Apr 5, 2009
3,131
Catalina '88 C30 tr/bs Oak Harbor, WA
The pulley needs to fit over the existing pulley but their ID is 0.064" smaller than the factory pulley. I am hoping that they just sent the wrong part. Very frustrating given that I have my kids coming from Arizona in a couple of weeks for a cruise and now the boat doesn't run.
 

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