Hoping someone can help with this one. My 13K mile, 2001 F4i sat in storage for 5 years. I recently decided to take it out. Changed oil, new air filter, flushed the coolant, new battery, and put in 1 gallon of gas. Bike started right up but then I noticed that gas was gushing out of the exhaust, at the joint with the can. The gas had completely drained within about 2 minutes. I did some searching and found this thread:

https://cbrforum.com/forum/f4i-main-...xhaust-138336/

basically word for word same problem I have. Unfortunately, that thread didn't come up with a solution other than check/replace the fuel pressure regulator.
So can anyone think of where to start? I'll replace all four plugs next week just in case one wasn't working. Has anyone had/seen this issue before? If so, how did you fix it? Help!

 

Why not start with the fuel pressure regulator, mine started going bad and had a strong gas smell out of the exhaust.

There is a thread showing how to check it, think you just pull the hose on the left side and start bike, it it leaks gas its bad. No gas should be leaking from the vacuum line side of the fpr.


Found this explanation for fuel coming out exhaust: ---

"the bike sat for a while obviously, the FPR will be gummed up by varnished gasoline. its a return regulator that allows/controls the amount of gas back into the gas tank. if its blocked it will over pressure the injectors & flood the engine by turning the key on when the fuel pump primes. you can watch this happen if you take of the airbox. just take it off & turn the key while watching inside the cylinders. if you see any gas go into the cylinder you can bet its the FPR."

its really common & a very easy fix. if you have not investigated the FPR i suggest looking there immediately. \\

 

Appreciate the help - thank you! I'll start a tear down next week. Here's the target: F4i Fuel Pressure Regulator - Imgur

 

To get to the fpr all you have to do is prop the tank up and it is on the left side of the bike right under the tank. Took me all of 5 mins to swap it out for my new one.

 

Even though you just changed your oil, after you remedy the fuel problem I suggest you change the oil again. Washing out the bearings from fuel in the oil is a common cause of premature engine failure. Cheap insurance.

 

Good news everyone. Total success, changed the FPR - very easy fix, took all of 10 minutes.

The part was $55 - here's a pic of the old one:
Photo Album - Imgur

Anyway, that's all it took - no more leaking gas out of the exhaust. The bike started up, spat out some heavy smoke then settled down to a smooth idle. Thank you bigboi18184!!!

 

No problem