SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: ka0tyk on September 09, 2012, 02:46:44 PM

Title: What causes this? flexplate hitting plate mount...
Post by: ka0tyk on September 09, 2012, 02:46:44 PM
switched from 3 point to a 4 point mount... the flexplate is new, and its flat... but as you can see in the pic its making contact with the plate mount.  theres a good 1/8" of room between them.  does the crank move around that much? is the flexplate flexing/bad?  i thought it might be the pump pushing forward on the engine but i tried pushing forward on the pump shaft and i cant get it to move at all.

(https://www.socaljetboats.com/proxy.php?request=http%3A%2F%2Fsphotos-a.xx.fbcdn.net%2Fhphotos-prn1%2Fs720x720%2F601576_10151083574564833_1355222259_n.jpg&hash=c409c08612f5321e291553a3229a7c5e6c733c4e)
Title: Re: What causes this? flexplate hitting plate mount...
Post by: 82daytona on September 09, 2012, 03:03:55 PM
More lube  ;)
Title: Re: What causes this? flexplate hitting plate mount...
Post by: Ralph Brunt on September 09, 2012, 03:06:47 PM
my guess is the motor plate is thicker than the original, skinny pto, pump moving n and out, and the flex plate flexing. crank should only move .008 or so.

it will wear itself in, lol
Title: Re: What causes this? flexplate hitting plate mount...
Post by: obnoxious001 on September 10, 2012, 12:10:51 AM
switched from 3 point to a 4 point mount... the flexplate is new, and its flat... but as you can see in the pic its making contact with the plate mount.  theres a good 1/8" of room between them.  does the crank move around that much? is the flexplate flexing/bad?  i thought it might be the pump pushing forward on the engine but i tried pushing forward on the pump shaft and i cant get it to move at all.


In some instances, a flexplate with no torque converter on it will "flex", and may make contact.  I saw one (a new, SFI thick one) make some sparks the other day on an engine I was running on the dyno.  The dyno operator commented that he sees it occasionally. 
Title: Re: What causes this? flexplate hitting plate mount...
Post by: GT Jets on September 10, 2012, 06:53:26 AM
I see this often. If it really bothers you, pull it and use a router with a speed control and clearance it a bit, seems redneck, but it works like a charm. Or like Ralph says...It will machine itself, it's only aluminum... ;)

GT
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