FX-1 Slight Bogging under full throttle

B

Brett Hanson

I bought a 95 Yamaha FX-1 at the end of last summer. When riding it, the engine will cut out power for just a split second, only sometimes, only under full throttle. It happens after being off the throttle completely or only under partial throttle, then suddenly pinning it. It'll bog down for a split second, then resume full power as normal. I'm wondering what could be causing it to bog like that? I was initially thinking it's a carb issue, perhaps the jetting is a bit off. After all, it has a Factory B Pipe and other mods to no end. I'll list the mods, because one of them is obviously playing some factor. If you guys could give me some opinions as to what the problem could be, that would be great.

Engine: 61x/61x
-Group K Hammer port job
-Factory B pipe
-Crank rebuilt with all prox parts
-Prox 81.5mm pistons
-Wetjet intake with carbon reeds
-Blackjack 46 carb
-MRD girdled head (non replaceable domes) @180psi
-DG tri oval waterbox
-#zero lightened flywheel
-MSD enhancer
-Flow control valve

Hull: 1995 Yamaha FX1
-Glass & carbon fiber reinforced
-140mm Kawi jet pump
-Waterdawg fiberglass hood
-Blowsion 1 way valve setup
-Waterdawg lowered pole bracket
-Waterdawg footholds
-SXR 13/21 solas dynafly impeller
-Pole shortened 3.5 inches
-UMI angled throttle
-Billet gas cap and all through hull fittings
-Straight bars
-800gph bilge with start/stop on handlebars
-Protec ride plate
-R&D scoop intake grate
 
Vumad

Vumad

Super Hero, with a cape!
Location
St. Pete, FL
If it is shutting off at WOT, it is a lean seizure. It is a warning sign for impending doom. Check your plugs and make sure they are a dark brown . If not, richen it up (if one plug is white and the other is brown, skip the tuning, you have a leak). If you don't get better plug colors by moving the screws, go up a jet size. If that doesn't solve the problem, you have an engine/intake leak, so then you must do a leak down test to find the source. Bad base gasket, bad crank seals, bad intake gaskets will cause this. Don't wait. Shutting off a WOT is the beginning of the end. Find the problem while you still have compression and hope for hone and pistons. If you press your luck, you'll be buying a bore too.
 
You must log in or register to reply here.
Top Bottom