Can someone me an idea what happened
07-20-2007 | 12:58 AM
#13
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From: Malta - Europe
My engines where 1997's and they had the defect. I'm not sure when Mercruiser fixed the problem but I know it was after 1997. You have to be VERT careful when you open up the hole not to score the matting surface of the o-ring. I opened mine up as much as I could and still leave enough mating surface for the o-ring to seal well. Hard to give you any definitive measurements though. I'm guessing that I doubled the x-sectional area of the feed hole...but it's still smaller than the other 7 holes....but large enough to prevent a lean condition with my bigger cams.
Harry
07-20-2007 | 01:04 AM
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From: Lake Conroe, TX.
Might not be THE problem, but isn't a 741 lift cam to big for a set of stock 502 heads. If you didn't lengthen the valves and strengthen the springs you might have had a bigger problem down the road.
I am actually asking the experts if I am right on this. have heard this from some local guys in the past.
I am actually asking the experts if I am right on this. have heard this from some local guys in the past.
07-20-2007 | 03:38 AM
#16
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From: Malta - Europe
Might not be THE problem, but isn't a 741 lift cam to big for a set of stock 502 heads. If you didn't lengthen the valves and strengthen the springs you might have had a bigger problem down the road.
I am actually asking the experts if I am right on this. have heard this from some local guys in the past.
I am actually asking the experts if I am right on this. have heard this from some local guys in the past.
The only thing that is stock is the head it self cause I changed the springs, rockers and valves. Note that mjb is right cause I checked the fuel rail and on the no 7 outlet there is only a little hole that feeds the injector.
Harry
07-20-2007 | 09:11 AM
#17
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From: Malta - Europe
My engines where 1997's and they had the defect. I'm not sure when Mercruiser fixed the problem but I know it was after 1997. You have to be VERT careful when you open up the hole not to score the matting surface of the o-ring. I opened mine up as much as I could and still leave enough mating surface for the o-ring to seal well. Hard to give you any definitive measurements though. I'm guessing that I doubled the x-sectional area of the feed hole...but it's still smaller than the other 7 holes....but large enough to prevent a lean condition with my bigger cams.
07-20-2007 | 09:23 AM
#18
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From: Lake Conroe, TX.
Cool. I don't have fuel injection. Still running the carbs. Good luck.
07-20-2007 | 09:26 AM
#19
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From: Fairhaven, MD.
Hard for me to say if 6.5mm is enough...that's only about 1/4" and still sounds pretty small. I did not drill mine. I used a dremmel tool with a long, slender grinding bit to open up the passage. I think you will be able to remove more material that way as opposed to a drill.
I do not think that there is an aftermarket fuel rail that will just bolt on to solve the problem. You may be able to get a later model mercruiser rail but I am pretty sure that the injectors on the MEFI 1's were different than MEFI 2's and I think the fuel rails are different...but I'm not sure of that?? I think your only quick bolt on option is to modify your fuel rail but maybe someone else in the know can comment.
I do not think that there is an aftermarket fuel rail that will just bolt on to solve the problem. You may be able to get a later model mercruiser rail but I am pretty sure that the injectors on the MEFI 1's were different than MEFI 2's and I think the fuel rails are different...but I'm not sure of that?? I think your only quick bolt on option is to modify your fuel rail but maybe someone else in the know can comment.
07-20-2007 | 09:58 AM
#20
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From: Malta - Europe
[QUOTE=mjb;2205023]Hard for me to say if 6.5mm is enough...that's only about 1/4" and still sounds pretty small. I did not drill mine. I used a dremmel tool with a long,
Mjb,
OK, I'll try to a least get the hole about 1/2". But thanks to you I found the problem, cause I couldn't figure out what happened,
Harry
Mjb,
OK, I'll try to a least get the hole about 1/2". But thanks to you I found the problem, cause I couldn't figure out what happened,
Harry
