502 VST Once over/Repair

[alldodge]

So far my cruiser is doing OK but I want to give the Vapor Seperator Tank (VST) the once over this winter. Accomplished several search's looking for information but came up no where except for the same parts list. I have down loaded the parts list and diagram but there are ten kits listed, which one should be used? Should I take the thing apart and see what it looks like before ordering anything? I have never opened one of these up but it doesn't look to be to complicated, anyone have any advise?

 

[Fun Times]

Re: 502 VST Once over/Repair

So far my cruiser is doing OK but I want to give the Vapor Seperator Tank (VST) the once over this winter. Accomplished several search's looking for information but came up no where except for the same parts list. I have down loaded the parts list and diagram but there are ten kits listed, which one should be used? Should I take the thing apart and see what it looks like before ordering anything? I have never opened one of these up but it doesn't look to be to complicated, anyone have any advise?

First off to open it up you will need a impact screw driver to Brake the lock tight they put on the screws, Trust me you will strip the head's the first try with out the impact.http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=93481

Have you priced the rebuild kit for those.$$$

If the engine is running ok then the only thing that you truly need to do, Just to be safe is pull it a part and carefully clean the fuel filter at the end of the fuel pump with carb cleaner. That filter will just twist off at the pump end, Becarefull not to put a hole in the screen, And also the filter has a little lock/ catch that holds it tight in place, But you just twist it and it should come off. If you hurt the filter then you will need to buy the hole rebuild kit, But if you are carefull then you would only need to buy the O ring for the top cover of the VST tank for around $10.00-$15.00. Hope this helps good luck with it.

The Only way to tell what kit is right for your engine would be a mercruiser dealer would need your engine serial number to look it up the right way.

Well I can't seem to find the Part number on line for the VST top cover only. But if you would like I could give you the phone number to a service shop that should have them in stock and could mail it to you if you wanted Or next week i could just find and post the part number here for you if no one eles does in the mean time. Let me know.

 

[alldodge]

Re: 502 VST Once over/Repair

First off to open it up you will need a impact screw driver to Brake the lock tight they put on the screws, Trust me you will strip the head's the first try with out the impact.http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=93481

Have you priced the rebuild kit for those.$$$

If the engine is running ok then the only thing that you truly need to do, Just to be safe is pull it a part and carefully clean the fuel filter at the end of the fuel pump with carb cleaner. That filter will just twist off at the pump end, Becarefull not to put a hole in the screen, And also the filter has a little lock/ catch that holds it tight in place, But you just twist it and it should come off. If you hurt the filter then you will need to buy the hole rebuild kit, But if you are carefull then you would only need to buy the O ring for the top cover of the VST tank for around $10.00-$15.00. Hope this helps good luck with it.

The Only way to tell what kit is right for your engine would be a mercruiser dealer would need your engine serial number to look it up the right way.

Well I can't seem to find the Part number on line for the VST top cover only. But if you would like I could give you the phone number to a service shop that should have them in stock and could mail it to you if you wanted Or next week i could just find and post the part number here for you if no one eles does in the mean time. Let me know.

Thanks for the pointers, I have an impact screw driver and I looked up the O-ring and the local boat shop should have it. So I guess I don't need a kit just the O-ring.

Thanks again
Hate cold weather, how many days is it to summer

 

[Don S]

Re: 502 VST Once over/Repair

Assuming you are talking about a Mercruiser engine, you can't just buy the seal for the cover. It only comes in the seal kit (around $90)
The part number for the seal kit is 808500 which would be all the items marked 11 in the picture below.

 

[Fun Times]

Re: 502 VST Once over/Repair

Thanks for the pointers, I have an impact screw driver and I looked up the O-ring and the local boat shop should have it. So I guess I don't need a kit just the O-ring.

Thanks again
Hate cold weather, how many days is it to summer

Hi, I was able to find the part number for the top cover only for you, And yes you can buy the O Ring by it's self for many years now, Back in the day we had a good amount of problems inside the vst tank with the fuel filter getting cloged up, And so on that our service shop where I worked asked/told mercruiser that they needed to sale the top cover "O" Ring by it's self Because we where in their so much, That they finally started selling the O ring by it's self. I just bought one for my 1996 454 mpi engine a few months ago myself, So I just found the part number for you at home. Punch in part number 25-803831 http://www.mercruiserparts.com/partsByNumber.asp in this link and it shows a good number.

Edit: Adding more info that may help others someday, https://forums.iboats.com/forum/eng...ter-idling-for-awhile?p=10527832#post10527832