View Full Version : 2002 F115TXRA Runs great above 1500 rpm terrible below that

07-17-2009, 07:35 PM
"Not sure what to try next. The motor is running great top end down to 1500 rpm. The motor seems to idle normally when first started. After putting the motor in gear it sputters and when given throttle it bogs pretty hard. After going from in and out of gear a couple of times it seems to correct itself. Because i launch out of a river or over reef, i have to leave the channel with my leg pretty high under 1500 rpm. After hitting open water as i trim down to a normal position, the the engine starts to bog again. When i bring it back to neutral the motor idles rough and sometimes stalls sometimes doesnt. Again after going from neutral to forward with throttle the motor bogs. It does that a couple of times and then again seems correct and is off like nothing is wrong. i have tried several things to fix the problem. i replaced rectifier/reg (i had a low voltage problem which i thought was causing my injectors to not work properly, the voltage is now correct)had my injectors cleaned and tested, replaced all of my filters, the last one being the high pressure fuel pump filter in the VST. That filter was in bad shape so i had high hopes that would fix the problem. Now the motor is running great above 1500rpm but still having issues at the lower rpms. Any ideas."

07-22-2009, 10:00 PM
"I was having the same problem with my f225. Talked to a Yamaha tech today and was advised to mount my primer bulb in a vertical position, as this is recommended by Yamaha. Fixed the problem. If mounted Horizontally it causes a vapor lock."

07-23-2009, 03:40 AM
"i will give that a try, thanks. It would be unreal if that fixed the problem but i can see how that could happen and my primer bulb is situated horizontally."