86 VFR750 Has no power under load.

This bike has no power under load. Seems to fall on its face when it hits second gear. When this happens, the engine stalls out. Idles and sounds fine and its getting fuel. Could I have fouled plugs? Any insights or suggestions would be most welcome.

 

Give us some background.

New bike? Been sitting? Fine one day, bad the next?

 

New bike to me. It has 66k on it. I have only had 3 months. Been busy fixing everything else. I think it sat for several years before I got. Previous owner passed in a car wreck. I purchased it from his boss who said it ran well. Not sure when that was. I have no reason not to believe him. I just pulled and replaced the rear spark plugs and they look pretty bad. Oily with some fuel and carbon. They obviously have not been changed in a long time. Going to tackle the front plugs before I try this yet again.

 

Just to add some more background. This bike had an automotive type fuel pump on it. Not sure why they did that. I assumed my issue was fuel related. It felt like it was not getting enough fuel. Replaced it with a factory pump and new filter. I believe the fuel issue is now fixed.

 

A weak spark can give those symptoms, so try new plugs first, then maybe check the resistance on the coils and plug leads, and confirm you are getting 12v at the ECU. I have had issues with some connector corrosion that lead to weak sparks. Have you checked the carbs for cleanliness yet?

 

Carb clean if it sat for that time period. Like the kind done properly and completely.
Seriously. Start reading, then read some more. There are some amazing write ups on proper V4 carb cleaning lurking in these pages.

And good luck and welcome. And you might re-locate this thread down to the 1st Gen page for some more action.

 

Thanks for the advice. I was afraid a carb was coming. I will read everything I can on the subject. Will I have a sync
issue if I do each carb one at a time? Patience is not my strong suit, however this VFR isn't giving me much choice. How do I move this thread to the 1st Gen discussion? Maybe someone else has a similar issue.

 

Thanks for all the advise. Turns out a carb cleaning and new set of sparks plugs did the trick. Bike pulls strongly
thru all the gears now. By next spring she will look like brand new.