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Kirbyvv
07-28-2010, 01:28 PM
I got the X-18 back together by July 4th weekend (after a deck off gas tank replacement project). I had the carb rebuilt and engine tuned by my local mechanic. She was running better than I've seen, 60 mph at about 4900 rpm. Its a stock 260 hp SBC. Slowly over the last couple weeks the performance has dropped off. I'm only getting about 4400 rpms now. Any ideas where I should start looking for the lost rpms?
I could take it back to my mechanic, but it isn't very convenient and they are very busy.

mrfixxall
07-28-2010, 01:41 PM
I got the X-18 back together by July 4th weekend (after a deck off gas tank replacement project). I had the carb rebuilt and engine tuned by my local mechanic. She was running better than I've seen, 60 mph at about 4900 rpm. Its a stock 260 hp SBC. Slowly over the last couple weeks the performance has dropped off. I'm only getting about 4400 rpms now. Any ideas where I should start looking for the lost rpms?
I could take it back to my mechanic, but it isn't very convenient and they are very busy.


its the hot weather,mine will loose rpm's when its hot out..try a evening cruise and see if you get your rpm's back..

Tidbart
07-28-2010, 02:16 PM
hot weather and ethanol-based fuel will drop the rpms.

Bob

gcarter
07-28-2010, 02:24 PM
Since you had it tuned, did the mechanic tighten the distributer?

mrfixxall
07-28-2010, 02:27 PM
you may also want to check the screen on the pick up tube, sometimes they get slag particles on the screen from welding the tank together..premimum fuel helps too..

Kirbyvv
07-28-2010, 02:54 PM
thanks, I'll check the pick-up and distributor. It's definately been hot, but I never had it drop off like this before.

LKSD
07-30-2010, 09:48 AM
Hot & Humid does rob power. Also depending on how you have the boat loaded with persons or gear it can slow you as well.. Other than that I would recommend that you at least do a quick recheck of you mechanicals to be safe.. :) Jamie / Lakeside.

Kirbyvv
08-02-2010, 08:51 AM
It must have been the heat and humidity. Ran right up to 4900 on Saturday with low humidity and 78 degrees.