port engine issues

[renestor]

Hello all, I recently boaught a 1990 350 EC with twin mercruiser 7.4 engines, it seems that my port engine is having some problems, It has recently been serviced by my mechanic, but there is still vapour in the exhaust, also it seems the carb isnt woking that good, because it stalls if the engine isnt shifted in above 1000 rpm. I have found out that this carb is a rebuilt one, it is a rochester quadrajet, the serial numbers are 7040208 IA 3149. My mechanic says that this carb isnt the one for my engine. I want to mention that boat runs good and maintains the rpm, when under way. Please can someone help, also if needed where can I find the right carb for my engine if I want to replace it, thanks

best regards

JI

 

[HGM]

I would do a few things to isolate the problem to the carburetor. First I would compare the #'s with the good carb. Mine didn't have tags on the carburetor but had #'s on the carb body. I would than switch Carburetors between engines. The carbs are easy to switch and it will insure that the problem is the carburetor. If you isolate the problem to the carburetor there are several re-builders that you can look at. Select your re-builder carefully. I was in a hurry when mine needed to be done last summer. Because of turn around time sending my own carburetors out I selected a company in California called Interstate 5 components. They offered carburetors without the need for exchange which would save me time. I installed the carburetors made only slight idle adjustments and the engines sounded good. I idled out of the marina to try them out. As soon as I applied a load they both bogged terribly. They would not perform under a load at all. If I tried to nurse the boat on plane I could only get around 3000 RPM. I removed both and contacted the I 5 immediately. After some discussion they agreed to refund my money without a re-stocking charge if I paid return shipping. I confirmed that they received them back and was told they would credit my account. That took a very long time and required several phone calls. I finally got a partial refund. After several more phone calls they agreed to refund the balance of my money. Thats was several months ago. I am still waiting! I found a local re-builder that did a great job. Good luck. The 350 is a great boat

 

[Quint4]

If you need a new carb, I suggest an Edelbrock 1410. They are ready to go out of the box and feature an electric choke for better starting. If you do not have electric chokes currently, you will have to run a hot wire from your ignition switch (key) and a ground wire to engine ground. No big deal.

http://www.summitracing.com/parts/edl-1410?gclid=CKqE59yss7QCFSOnPAodKQQA3Q

 

[renestor]

Thanks very much for all the answers, also want to mention that the port engine runs a bit hotter than the starboard one. It gests close to 145°, but it doesnt get any hotter, is this normal, or there could be something wrong, what would be the optimal engine temps. thanks

best regards

JI

 

[HGM]

Raw Water cooled?

 

[renestor]

yes its raw water cooled

 

[HGM]

Is your 350 inboards?

 

[renestor]

Yes twin 454 mercruisers

 

[HGM]

I was asking because Mercruiser uses a ignition interrupt switch switch on there stern drives.