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Jerky at low rpms

Old 07-05-2010, 05:45 PM
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Join Date: Nov 2009
Posts: 4
Default Jerky at low rpms

I have an 02 F4i.

I bought it used at ~12k miles, its now right about 15k, and lately I haven noticed that in first/second gear, if my rpms are anywhere in the 4,000 range, the bike really seems to be jerky. it feels like it might not be getting a constant amount of fuel or something of the sort. i drove around keeping the throttle very steady at ~20-25 mph in 2nd and could definitely feel it acting a little funny. i am going in for an oil change already in a couple days, but was curious if this was something others had experienced or knew about, and if so, what could i do to fix this?

Old 07-05-2010, 07:55 PM
yog182's Avatar
Senior Member
Join Date: Dec 2008
Location: Harrisburg, PA
Posts: 513

I too actually have the same problem.. You can actually see the needle on the tack be uneasy as well. I currently right now am blaming it on my chain.. I will be looking into that here soon. Any one else got any suggestions?
Old 07-05-2010, 08:17 PM
tanrush's Avatar
Join Date: Jan 2010
Location: Parts Unknown, TN
Posts: 85
Default Here is the fix

I have been chasing this tiger for a couple months now and I think I have finally seen the light after being hardheaded. The group here has been saying FPR so it is a regular problems for our bikes.

Symtoms I have
Hard start usually have to give it gas
Bike reeks of gas smell, unburned coming out of exhaust (pipe is loaded with carbon on tailpipe)
Terrible gas mileage 25 miles per gallon, 100 miles tankful
Poor idle, bike must warm up to take off
Jerky, hard to take off from stop, lacks power, did I mention jerky like the bike is not getting enough gas and cuts in and out all the time. (Really sucks to ride kinda jerky)

I ordered my fuel pressure regulator from the below link. It is item 20, you also need the o ring.


Things I have done so far to my 02 F4I.
New K&N Air filter
New Iridium spark plugs
Cleaned the throttle bodies with sea foam
New clutch
New pipe
New Hong Kong shorties levels
Michelin Road Pilot 2's, front and rear (Derby Cycle.com)

Hope this helps, I should know if it solves my problems by this weekend.
Old 07-05-2010, 08:57 PM
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Join Date: Nov 2009
Posts: 4

thanks for the responses.

i am going to be getting the oil changed in the next couple days. i will check with the place to get their opinion (they are a pretty large place that does a lot of service) so they might have some insight. if i find out anything useful ill post it here
Old 07-06-2010, 01:04 AM
Junior Member
Join Date: Jun 2010
Posts: 15

I have the same problem with my bike aswell, but the rpm's do not jump around and its gets good gas milage, and took it in andthey said everything was fine, i just learned to deal with it. My bike has 14,000 miles on it.
Old 07-07-2010, 02:06 AM
Syphen's Avatar
Senior Member
Join Date: Apr 2006
Posts: 456

in going from an F4 to an F4i, I've discovered that when warmed up, carbs are way smoother at low RPM. Fuel injection can be a little jerky until after 3-4000rpm. I just ignore it and keep the rpms up!
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