View Full Version : Starts fine idles fine then loses power after 5 min

07-19-2009, 01:14 PM
"Our motor cuts out to an idle speed after about 5 min at full throttle with the prop engaged.It seems to run fine when the muffs are on or in a tank. We have changed the carb, changed the water pump, compression is good in the cylinders, we have changed the gas source (in case of bad gas). Problem persists.We have had it back in the shop 3 times with no success. My brother in law wants to blow up the boat . Does anyone have any less dramatic solutions?"

07-22-2009, 02:35 PM
Start by telling us what kind of motor?

07-22-2009, 06:46 PM
The boat is up at the inlaws lake so I am not 100% sure but I think it is a 70hp

07-31-2009, 01:08 PM
This may sound obvious but I have seen it catch people before. Make sure the vent is open and clear on the gas tank. My dad has a portable tank and you have to open a vent knob on the tank. This simple thing recently cost him a bunch as he started to replace fuel pumps etc.

08-02-2009, 11:47 AM
the vent was open. we have tried both the main tank and a portable tank

08-09-2009, 09:46 AM
looks like the problem was a faulty sensor. Working fine with sensor detatched .will replace and see what happens