I have 502's with B & M 420 Mega blowers. Does anyone have an Idea how often these blowers should be serviced. I know the teflon inside can wear but not sure how long they hold up. Also I know Holly bought B & M years ago. Not sure if they still sell parts Pulleys , belts etc. I may want to order smaller pulleys and belts. Are there other compnaies that sell compatible pulleys etc.

Thanks in advance.

Yes you can still buy all the part for these summit still list them.

teague makes the stuff you can't buy anymore from Holley.

The blower shop also does service/ rebuilds on them.




Darrell.

do you have boost gauges ? if so and the boost levals are where they should be, I would consider the seals fine

I don't know where you live, but you can call Darin Mayer's shop in Stevensville, Michigan. He can service/repair/rebuild your blowers too. (269) 428-5070. I know of a few guys who have taken their blowers to him for rebuilds, etc.---even the teflon strips.

Stevensville is located right along I-94 and Lake Michigan (SW Michigan) and about 20 miles north of the Indiana border.

Thanks to all for your help. Does anyone have an opinion on how often to change the gear oil inside the blower. I don't put alot of hours on them maybe 20 - 40 hrs/yr.

I have boost gauges but to be honest was never real confident with the accuracy. I have'nt seen a real change on the gauge. Ive had the motors frshened up but still can't seem to get back to my top speed numbers when everything was brand new. I'm down 2-4 mph

With the amount of hours you put on, annually should be fine.

Had a freind with the same problem , took all the gear he had collected over the last 4 year off the boat and fond that 2 mph he lost . Just a thougth .