Carb Questions

[FZRguy]

My FZR has 26k plus miles and I think it’s time for a carb kit. Not sure if I should get the high altitude kit or not. No current plans to ride to sea level, but ya never know. Also, I read that the emulsion tubes are prone to wearing on Mikuni carbs and should be replaced. Tried to id them in the manual but didn’t see anything of that name. Are they called something else? I think that they have to be ordered from a dealer.

[Anonymous]

Strongly suggest you take it to TK and just have them rejet the bike on the Dyno.

I don't know how an emulsion tube would "wear" since it isn't a moving part, but hey, it is a Yamaha.

[FZRguy]

I’ll get it running and at least run it on the dyno to see where I'm at. But it's always run perfectly. Hey, it is a Yamaha. :D

[zukigirl]

Oh.....you are not asking questions about carbohydrates.....

LOL

[FZRguy]

I can fix your carbohydrates too… ;)

[RAGrote]

Not sure if I should get the high altitude kit or not.

Without doing A/F measurements or doing spark plug reads you'll never know if you need different carb needles/mains/settings. Unless, of course, the bike is displaying a distinct problem in a specific throttle opening. If the bike is running perfectly with the stock carbs, do a plug check and work from there.
BTW, carbs have a tendency to run rich at altitude.
As for the emulsion tubes. Google "Yamaha emulsion tubes" and you'll get some answers on how to remove them and what to look for.

c-ya

[FZRguy]

Thanks for the info. Factory Pro makes replacement emulsion tubes for the FZR and other bikes. The bike has stock jetting with a K&N element and V&H slip-on. No symptoms of running rich and the plugs looked fine last time I replaced them. I figure it’s always run a little rich b/c of the elevation tho. My current problem is that it’s flooded and won’t start...also maybe bad gas b/c it’s been sitting for almost two months. Hopefully, a set of fresh plugs will get it going. If not, the carbs will prolly need to be cleaned, which is why I was thinking of installing a jet kit while I have them off.

[Jackal]

Yes the emulsion tubes can go out of round quickly on FZRs. I put individual filters on and adjusted my main jets/needles to where the work decent. More top end power than it used to have by a little bit, I'm sure it is running a bit rich though (just havn't had money to buy more jets), and I'm sure it would benifit from being dyno tuned. The thing I like most is the ferocious intake noise with the individual filters.

Rather than paying a bunch for dyno tuning it though, I plan on taking it to the drag strip when it opens back up and tune it for best time and trap speed on the spot (I'll just bring all my tools and jets down there).

[Kim-n-Dean]

Thanks for the info. Factory Pro makes replacement emulsion tubes for the FZR and other bikes. The bike has stock jetting with a K&N element and V&H slip-on. No symptoms of running rich and the plugs looked fine last time I replaced them. I figure it’s always run a little rich b/c of the elevation tho. My current problem is that it’s flooded and won’t start...also maybe bad gas b/c it’s been sitting for almost two months. Hopefully, a set of fresh plugs will get it going. If not, the carbs will prolly need to be cleaned, which is why I was thinking of installing a jet kit while I have them off.

You probably don't have to rejet. The slip-on will lean it out a little and you're still safe for lower altitudes. I know that gas starts to create a varnish after only 30 days. However, I never put stabilizer in my boat and it sits for over 4 months and I've never had a problem. I don't recommend it, though.

[FZRguy]

I got it running last weekend. I was thinking about individual filters too, but have heard that it runs better with the stock box. I’ll put it on the dyno before I change anything.

[kevplus2]

it can be a total biznatch to get the carbs set up right at this altitude when running pods. by dumping the airbox for the pods you are losing alot of the vacuum that the carbs require to open. the result can be alot of surging at partial throttle openings but then running like a raped ape at full throttle

[Anonymous]

BTW, carbs have a tendency to run rich at altitude.

Yeah, physics will do that to ya... :lol: