Hey Everyone,

I’m fairly new to tinkering but in the past year I have had some help fitting a new engine (F3 engine with about 6k miles on the clock), cleaning carbs and jets, rebuilding front brakes, changing chain and sprockets (standard size), which has allowed me to service the bike, repair a fuel leak from the T-joints going into each carb, and identify and fix a coolant leak myself.

After I had cleaned the carbs (and unfortunately not made sure the tank was fully clean of any bits, even though I changed the fuel filter, duh!) the bike was running pretty nicely but was occasionally sticking at 3000rpm but after a while that sorted itself out! I then noticed the fuel leak from the T joints I mentioned earlier but did not have time to repair it before leaving the country for 6 months.

Before I left I made sure I put the bike away properly, drained the carbs, disconnected the battery, kept it on paddock stands etc, and when I returned I was able to get the carbs off, split the rack to replace the seals on the T Joints, put it back together and got it running again with no leak, happy days! Well not entirely…

The bike is idling okay at around 1000/1100 rpm but fluctuating a little bit, and riding pretty nicely from 7k rpm onwards but between 5k and 7k especially it is bogging down hard. If I am within this range and I open up the throttle the bike splutters and jolts, giving me hardly any power until it hits 7k and flys again! I’m hoping that this could be down to me needing to balance the carbs and not me having to split the bike down and clean the carbs again but I wanted some expert advice please…?

One more thing to note, I had to really give my carbs a whack with a rubber hammer in order to split the rack (don’t think they had been split for a while) so not sure if this is would have caused any issues but wanted to mention it.

Any help would be much appreciated!

Ant


Here she is, what a beaut hey!

 

Update:

Balanced the Carbs, still have the same issue with bogging down

 

I suspect you will have to strip and clean the carbs again as they are very sensitive to any sort of muck in them at all.

 

Hello mate I'm sorry to hear you have this absolute BALLACHE of a pickle, been chasing this for years and it turned out the mixture after new headers was WAY too rich and had to put smaller jets in and a pipercross air filter. It didn't make any sense at all! have you checked your spark plugs for nasty black soot? id take it to ma dyno (about £40) and get a sniffer down the old exhaust pipe to see what's what and if it is just mucky carbs like a passageway that's blocked or a crappy fuel jet needle leaking

 

If it ran good before you parked it. Then it sat for 6 months and now doesn't run the same.
Then you need to clean the carbs again. Very possible 1 of the jets or air bleeds is plugged, even if you drained the carbs before parking.

 

That is typically pattern with exhaust upgrades. It increases high-end flow, but slows down mid-range. Effect is too-rich factory mid-range mixtures get even worse to point of stumbling. You found matching carb settings of leaning out mid-range, good job!

 

I concur with the fuel siphon finding. I had a very much like issue and supplanted the siphon with one I paid off the gathering for $50 delivered and presently the issue has disappeared. I enthusiastically suggest changing the siphon out. Concerning supplanting the channel I've looked cautiously at my old siphon and the channel is by all accounts plasti-welded to the remainder of the unit. it doesn't seem to be something intended to be supplanted or taken out by any means. I would suggest supplanting the whole unit since units can be found somewhat economically. This issue typically comes around at 20,000 or so miles however, so the way that you're having the issue at such low miles, to me recommends two things: 1. the person you got it from supplanted the measures with lower miles 2. the way that the bicycle sat for such a long time really intends that there's gummed up gas in the channel GL-it's something little don't stress over it to an extreme. until further notice I suggest keeping the tank as full as could be expected. as far as I might be concerned, the issue wouldn't appear until I had two bars or less of fuel.



Kodi nox

 

Hi All,

Apologies for the delay in responding but grateful appreciate the help and advice! You’ll be happy to know we have fixed the issue!

We took the carbs apart and checked all the individual parts and found that they were all in great condition still, but we found that one of the air/fuel mixture screws had been screwed all the way in. Once we checked the manual and found we needed to screw then all the way in then 2.25 turns back out, we did this, put the bike back together and she is riding like an absolute beaut!!! Better than I have had her running before! A combination of balancing the carbs and sorting the air/fuel mixture screws!

Thanks again everyone! Unfortunately due to the weather she has not been out too much but lovely to know when I need her she is ready and waiting!

Safe riding out there guys!

Ant