After crashing into the back of a pickup truck and going down on the right side, my 1996 F3 has developed a 30mph BOG. You could rev all you want sitting still, no problem. The minute the speedo hits around 30mph, it doesn't matter what you do with the throttle, (1/2, 2/3, WOT), it'll bog & sometimes surge momentarily.

Prior to the crash, I've had zero problems.Amechanicatone shop seem to think the carbs needed to be cleaned, but what if that isn't the problem? There are no apparent vaccum leaks when I visually inspected all the hoses. It almost seems as though some electrical component has an intermitten signal and something isn't grounded properly. The instrument clusters initially didn't work, replugging the wiring harness back into the cluster led to the speedo coming alive but not the tach, and then the tach came alive after going around the block a few times.

Does anyone have a clue as to what happens at 30mph? What is the logic behind the madness? What electrical circuits, switches, relays, ignition coils, should I be checking to ensure this isn't something that isBEHAVING like it's dirty carb problem?

What areas should I check first to determine that it's not an air-valve, PAIR, or electricalsensor problem? What's the path of least resistance so that I can get a warm fuzzy that other circuits or systems are functioning within spec before I tear into the carbs to clean the primary & secondary circuit?

 

do you gauges or lights blink when this happens ?

 

No the lights & gages do not blink, if they did it would't be a mystical problem. It would be clearly be an electrical problem if they did.

 

did the bike sit for any period of time after you crashed it ?

 

Does it bog at 30 in every gear?

 

No, it's been started up and ran about once a week or about every 10 days. Initially I thought it might be the gas, or that it's low on fuel, so I filled up the tank. That of course did not make the problem go away. I rode it to the nearest Honda dealership about 12 miles away 2 weeks ago. They looked at it and thought it might need a carb cleaning, but couldn't be sure until they've taken the carbs apart and estimated the charges to be around $500. If it's not the carbs, they said they would go from there. I wasn't about to let the bike be a money pit, putting more $$ into it than what it's worth. If it's the carbs, I could try to do the cleaning at my own leisure. But before I commencing on tearing the carbs apart, I'd like to know whether theremight be otherpossibilities that could be the cause of thismystical bogging.

And yes, it doesn't matter what gear I'm in (1st, 2nd, 3rd, etc.) as long asthe bike has gone faster than 30mph, the bogging occurs. Below 30mph, it's happy as a clam, rev all you want without issues.

 

How fast was the crash?

Its hard to tell after a crash. You may end up pulling damn near everything off the bike and doing a visual on everything.

It could be the carbs. 30+ mph puts a certain load on the bike that a carb issue may reveal itself. Cleaning the carbs is a good idea for maintenance anyway, so it won't be a total waste even if its not the problem. But 500 bucks is a lot of money for that. Like you said, do it yourself, its not that hard. You could do it in about 3-4 hours if you've never done one, or about 1-2 hours if you have. For that bike, I would just remove the float bowls, clean them, remove all the jets and clean those as well. Your pilot jets are all set to a certain spot. I would record how many turns they are out and put them back to the same spot. as not all four will be the same. start off by turning them in and counting how many turns.. should be around 1 and half.

I would check the sparkplugs. The porcelin could have cracked during the crash. A weak spark may not show up until a bigger load is put on the bike.

Also, make sure the coil pack didnt get jarded loose or cracked.

I don't know of any sensors on that model that would cause any of these things to happen. Pull your seat off and make sure all of the relays and such are still seated in thier rubber straps. other than that, just a visual of all the electrical components for cracks is about all I can suggest.

 

Got a different bike, thinking about selling this one or parting it out. Ideas? Takers?

 

where are you at, and how much were you looking to get?