Brand new 5.7 runs poorly

[NHGuy]

Re: Brand new 5.7 runs poorly

Here is a link to another guy's EST thread. He had some trouble with his, but apparently fixed it, since the posts stopped. http://forums.iboats.com/mercruiser...co-est-ignition-not-going-so-well-609960.html
It includes a nice diagram that Don made up for wiring the EST. I'd take a look through that and also look at what you have done too.
Break it up into little steps, maybe you missed something.
A new 350 should rip.

 

[13crazyhorse]

Re: Brand new 5.7 runs poorly

Bond-o and NHGuy, thanks for your input it is greatly appreciated. I tend to think it's not the ignition I purchased the motor and ignition from the same source (Michigan Motorz) who specialize in boat engines and it's very simple and seemingly foolproof (?). Perhaps the retardation of the timing was a band aide for the lack of fuel. I'm not going to get back to the boat for a few days but I think I'll try to eliminate one thing at a time. I'm going to run the engine off an outboard tank to rule out any tank or fuel problems on that end. I'll recheck the ignition again and if no change I'll pull the carb and go through that again. I'll keep you posted on the results and thanks again.

 

[NHGuy]

Re: Brand new 5.7 runs poorly

I apologize for how I spoke up about vacuum testing. Didn't look at the attachment til just now.
The type of testing on that post can be a huge help in determining what is going on.

 

[13crazyhorse]

Re: Brand new 5.7 runs poorly

NHGuy,
Thanks I may run up sunday and try some new gas in a remote tank if that doesn't work I'll take my vacuum gauge and if I've got the right fitting give that a try. If I can't determine anything, then I'll pull the carb and bring it back home for another going over. Thanks.

 

[NHGuy]

Re: Brand new 5.7 runs poorly

A remote tank may point out things, it's a good move. Also bring a glass jar to check the contents of your water/fuel separator. If it's full of junk that's a big omen. Bring a can of carb cleaner and shoot some around the intake manifold to heads connection, also around the carb base and carb pivot shafts. Any speed change is a leak. But Bondo is a very experienced guy, you are probably suffering a fuel shortage.
If your fuel is OK and you suspect the carb find a local carb guy. It's June 25, it's summer, who can wait? You are better off finding a local carb pro with a quicker turnaround so you get to go boating sooner. If the guy is fair he'd maybe just go over what has been done and correct any deficiencies. OTOH his method might be just do it his way so he knows what's been done, that has merit too.
A new motor should act right. You will get it fixed, I can tell...

 

[13crazyhorse]

Re: Brand new 5.7 runs poorly

OK sorry for the delay in this update but I've been busy and haven't had time to get to the boat. Since my last trip up to the boat I bought another project boat and it happened to have a similar quadrajet carb on it. The boat had been sitting for a few years but the carb looked pretty clean and was rebuilt according to the paperwork I got with the boat. I pulled it off and decided to try it on my boat since that only takes a few minutes to change. No more coughing, backfiring and I could get more rpms out of the motor! It's still not fine tuned cause I only get about 3k rpms and about 13 mph out of it now but it's nice and smooth. I can adjust the high and low speed jet on this older carb which I haven't done yet under load I didn't have any help. But I'm gaining on this project in the right direction.