3AJ Running Rough
 

Hi Guys, did a top end rebuild recently, set the carb up according to yamaha workshop manual. Bike runs fine going through the gears - but - at about 70mph cruising, the bike feels like it is running out of fuel and occasionally backfires.

The pilot screw was set to two turns out, I adjusted it to 3 turns out- no difference. Any help/ideas would be appreciated.

Hi.

Have you had a look at your airfilter lately? Had the same problem after I rebuilt my bike,and started it up.After I cleaned the airfilter and adjusted the secundstage opening the bike run fine again.

Cheers.

Tom

The pilot screw will have little effect. Its predominantly only used when the bike is idleing.

Backfiring is a sign of a lean mixture (too much air) but dont confuse this with over run which is common with singles.

Do you have the standard exhaust on ??

Were those carby mounting blocks OK? Seems to be a common problem. They will make your bike run lean if they leak.

Steve

Hi Ted, I met u at HUUK. (Blue 3aj, camped at the top of the field, bike was burning oil then). Whats over run? and what can I do about a lean mixture

To start with, put the pilot back where it was. As long as it starts fine and idles fine with the stock pilot setting, just leave well alone !

Did you sort the oil leak ??.. Perhaps it was just condensation ???

The best way to determine if its running lean or rich is to find a garage with a gas analyser to "sniff" your exhaust.

Failing that, you could try moving the little Circlip on the needle adjustment on the carb. Dropping it down a notch will make the open throttle position a little richer.

Have you got the standard exhaust on ??? Is the air filter clean ?? are the carb rubbers in good condition and tight ??

Overrun is slight popping when you shut the thottle on a big single "bom bom bom" etc

I would set your carb and bike to as close as stock as possible then make small adjustments to the fueling.

Also check your tank is breathing ok (no trapped breather pipes etc)

Rough running ttr 600re
 

Hi Guys,
I have a ttr600 re 05 with 1000miles on it.
It started to :like run out of petrol: at high speed like going on reserve.
Plenty of fuel, i only get this at high speed.
I changed the plug to an iridium one and checked and taped the ht lead onto coil and new ht cap.
Cleaned the filter and oiled it.
Fresh fuel.
Any ideas, any help will be appreciated.
Cheers Chris....

Does the gas tank vent properly?

Nothing worse than a bike that doesn't work properly :(

and some other causes ...
 

Checking the tank vent is definitely a good one.
Then, there is a little filter on top of the float valve seat, inside carb. It is so tiny as to clog up swiftly. Just remove it, then take out into woods and shoot it, then burn it. Then install an inline fuel filter.
Third, clean air filter, it might look clean but that does not mean it is.

Btw, 2005 and only 1000 miles - that is a lot of just standing - chances are something else in your carb has gunked up with old fuel.

Auke

Do 3AJ`s have a tank vent then? where would that be located? i thought it just vented through the gas cap.

Mezo.

Ueh yeah, they should just vent through the cap... but who knows if it works properly.

I have a 23ltr acerbis tank on, which has a different cap on, sorry for misleading..... :innocent:

Have just seen the 1000miles since '05. I think the carb is full of goo.

Thanks guys,
I check the breather pipe on top of the filler cap its clear. how do i know if the filler cap is venting right?
I stripped off the carb nightmare job. There must be an easier way than undoing the clips forcing the airbox pipes back into the air box, as well as undoing the throttle cables?????
Anyway now removed, (two rubber o-rings about the size of a 1p and one really small one fell on the floor dont know where they came from doh) i unscrewed the bottom of the primary where the float bowls are i see the jets, all looks clean. I sprayed up the jet with brake cleaner anyway. Where is this little sod of a filter located, and how do i remove it.
Thanks again any help will be appreciated.
Cheers Chris..........:oops2:

Huh?
 

Is it a 3AJ (tenere) or a TT600RE?
Anyway, if you'd like to know where the O-rings came from try to get hold of an exploded biew of carb and inlet rubbers etc. I don't know about p's, I'm from Euro / swedish crwon country.
The filter: you took off the float bowl, so you see the jets and the float. The float actuates a needle which falls into a little copper tube. This is the float valve seat. If remove the float (carefully tap out the hinge pin) you can remove the little screw holding the seat in place. Then, VERY CAREFULLY WITHOUT FORCE retract the seat from carb body. You'll see the little bugger (=filter) on top of the seat. Just unclick.
Hint: there is an O-ring between carb body and float bowl. It is ribbed.

Good luck! A

The original OP had problems with an 3aj (back in 2007)

This thread was recently revived regarding a question for a tt600...So yeah, not easy to follw what the %&(# is going on =)

The vent should be able to let air into the gastank, so it wont build uderpressure, which would work against the vacuumoperated fueltap :)

Thanks guys,
I have removed the little filter, and built the carb back up after cleaning all the jets.
The rubber o-rings that fell on the floor was from the over flow pipes on the carb to keep them together. No big deal they will go back on after in reinstall the carb back on the bike.
Hopefully this clean up will cure the rough running.
I will post on the out come.
Cheers Chris