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-   -   Looking for info tech on the 525 EFI (https://www.offshoreonly.com/forums/general-q/175624-looking-info-tech-525-efi.html)

Griff 12-17-2007 08:58 PM

If you are trying to make a copy of the 525EFI and using the computer, then use the custom grind 741 on a 114 lob sep.

Linster 12-17-2007 09:31 PM

The computer program is pretty unforgiving. If you really want a 525 you need to match the engine as close as possible if not exact. The cam must be exact as the sensors read vacumn to control idle. Controling idle is the hard part of a EFI. I would only do this with a marine stock 502 bottom end, the 525 cam which as stated is the 741 on a 114 lobe, Elderbrok aluminum heads, and CMI long sweep exhaust. Good luck & I hope it works.

CHEKT OUT 12-17-2007 10:16 PM

Thanks for the info so far, I'm kinda wary but think I'll go for it, hell worst case I slap a carb and intake on and I've still got a big cam and bad ass exhaust.

CHEKT OUT 12-17-2007 10:32 PM


Originally Posted by alamo28 (Post 2375213)
Check Out

I have found a lot of info on mercruiserpartsonline.com without a serial number. I will also go through some customers files and see if anybody has a 525 EFI and get you a serial number if the previous does not work.

As far as responses to your posts, It depends on the question and how many people can help you. I am sure that the people do not know you personally and will not answer your questions out of spite!

Just wanted to say great sugestion, I even found serial numbers on there.

kennyo 12-18-2007 08:53 AM

Does the 525 use the stock dog bone roller lifters with the "741" cam?

Young Performance 12-18-2007 09:20 AM


Originally Posted by kennyo (Post 2375698)
Does the 525 use the stock dog bone roller lifters with the "741" cam?

No. They use the style with the tie bar.

skaterboy 12-18-2007 04:17 PM

CHEKT OUT,

In case you are interested, I have many extra parts from two 525EFI after converting my engines to Whipple Blowers. They include heads, computers, wire harness, fuel injectors, manifolds, fuel pumps, Plenums and more. Will offer at a good price. Tell me what you need.

Ray

H2Xmark 12-18-2007 07:20 PM

what kind of cyl. heads did you install to replace the edelbrock's with?

paradigm shift 12-18-2007 10:56 PM


Originally Posted by CHEKT OUT (Post 2375470)
Thanks for the info so far, I'm kinda wary but think I'll go for it, hell worst case I slap a carb and intake on and I've still got a big cam and bad ass exhaust.

Do yourself a favor and get a wide band O2 sensor and weld a bung in your exhaust. Just my .02 reasons.
1. Use to test initail tune before you hurt parts.
2. Can be used for set up with new ECM program fien tuning.
3. Use it to set up your carb fine tune.


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