Ok guys here's my situation. I have a 94 F2 with about 28000 miles on it. Just put a new battery cleaned the carb's, oilchange, new air filter. Just basic maintainance. Rode it around town for 2 weeks and no problems. Took it out on the interstate for my first long ride and 30 minutes into the ride she started to bog down lose power and finally died. There was nothing to indicate any problems. It didnt run hot no other lights came on it just starting loseing power then as I started to slow down killed on me and would'nt restart. After about an hour of letting it cool back down it would start up. It doesnt sound as If it has the same power it did. When you rev it it has a lower exhaust note than before. I checked the battery it holds steady at 12 at idle and at 12-13 at 4000 rpms. I can get the bike started everyday ( it takes several tries right now ) but I don't trust it to ride again untill I get this figured out. Now it started to do this last winter before I put it in the garage so this is not something new that just happened after I did the maintainance. Any help would be appreciated. I am not sure if it's R/R related as it does'nt quite have all the symptoms for that and don't want to just start buying parts that are not needed.

 

This is kinda the classic description of what a F2 does when it runs out of gas. I know mine has done it a time or 3

Charging system sounds like it it doing ok if you're getting 13+ volts at mid rpm's.

It is possible you vapor locked your fuel tank. There are 2 hoses that come off the back of the tank and run to nowhere - these are vent lines - they need to be clear of any obstructions - bug around my areas love to build nests in openings like that, they completely seal small holes up with a dirt-type of filler.

Open the fuel tank up then try running the bike - see if it runs better.

Also shine a light down in the exhaust - make sure there isn't anything obstructing in there.

Other thing to check is the vacuum line running to your petcock - make sure it isn't cracked or leaking at the ends - it's a $1 part at any auto parts store - replace it just to be safe.

 

Dude that's low voltage for these bikes, you know that

12.8+- volts at idle is expected, 13.8+- volts at 3.5k + rpm..

You're getting a reduced charge from your R/R it sounds like to me. Classic symptom is the bike starts to die as you get less and less spark.


An easy way to test though is charge the battery fully and run the bike for a bit. If it puts the pep back into it, you know it's a charging system issue, which 99/100 times is the R/R on these beasts.

 

[quote=JesseAwesome;1068035]Dude that's low voltage for these bikes, you know that

12.8+- volts at idle is expected, 13.8+- volts at 3.5k + rpm..

You're getting a reduced charge from your R/R it sounds like to me. Classic symptom is the bike starts to die as you get less and less spark.


I was told that that voltage was the norm for my bike from a mechanic. Also if it was the r/r why would everything work again after the bike cools back off. You would think if I am losing voltage that I should see the battery slowly starting to go down as the battery life dwindles right?

 

[quote=adrenalnjunky;1068001]This is kinda the classic description of what a F2 does when it runs out of gas. I know mine has done it a time or 3

Charging system sounds like it it doing ok if you're getting 13+ volts at mid rpm's.

It is possible you vapor locked your fuel tank. There are 2 hoses that come off the back of the tank and run to nowhere - these are vent lines - they need to be clear of any obstructions - bug around my areas love to build nests in openings like that, they completely seal small holes up with a dirt-type of filler.

Well I know the hoses your referring to as I removed them and inspected when I disassembled everything to get to my carbs awhile back. I had to replace the existing gas that was in the tank so I know those lines are good. As for the tailpipe I am not sure but while it sat it was in my garage covered up but I will check. I am not ruling anything out at this point.

 

Seth - Jesse's right - I was initially thinking battery/RR, but had misread your post and thought u said you were getting well over 13V @ 4K rpm.

the RR can be getting hot and crapping out with the temp increase. As it cools off, it regains some functionality.

either way - starving for fuel or decreased spark, the bike would have a dropoff on power and eventually die.

When running out of gas though - since carbs aren't completely uniform in their consumption, you tend to drop a cylinder first and notice the change in exhaust note. If your bike didn't drop a cylinder, it's most likely the charging system.

you cuold pull a plug out when it's acting up, and ground it to check the spark - nice blue spark is what you're looking for - fat yellow spark is a sign of bad plugs or weak battery.

 

Well I didnt run out of gas and dont think I dropped a cylinder I am still thinking electrical. I still was thinking r/r but it didnt have all the symptoms others were posting about a bad r/r. It doesnt sound like the stator or the CDI so I was still leaning to the r/r but wasnt convinced.

 

I had a similar problem on my bike, and couldnt seem to figure it out, on the roads it was working great, and then i hit the highway and had the same problem. I think i found the problem for mine- the fuel hose was a little too long, and it was kinking. While it was cool, there was a little flow but when it got hot it seemed to Kink and block the fuel line, running it out of gas, but when it cooled down, it opened up a little bit again. I havent run it on the highway again yet, but it seems to be working well now, just putting my 2 cents in

 

I will check that. They are the factory fuel lines but hey you never know. I hope it's that simple but with this motorcycle I don't think I can be so lucky....lol

 

Well my fuel line isnt kinked so that is not it but worth checking. Any other suggestions would be appreciated before I have to pay someone to figure this out.