Hi all
after three years I have finally got my old Z1R running. been starting up on and off for the last week without any problems but today it struggled to fire up on number 4 cylinder. It kicked in after a few seconds and all seemed fine. It has however started to dump fuel out of the bowl overflow pipes on number 2 and four carbs when engine is running and when it is off. Hasnt been doing this all week. I noticed that just before fuel is dumped the revs drop a bit then go back to normal once fuel has stopped leaking. Carbs have been refurbished using the keyster kits and float levels set. Floats were checked for holes before fitting. Anyone got any ideas why this is happening
thanks
Hello Guest User,
Please feel free to have a look around the forum but be aware that as an unregistered guest you can't see all of it and you can't post.
To access these 'Registered Users Only' areas simply register and login.
Please feel free to have a look around the forum but be aware that as an unregistered guest you can't see all of it and you can't post.
To access these 'Registered Users Only' areas simply register and login.
help flooding/over flowing carbs
Moderators: paul doran, Taffus, KeithZ1R, chrisu
Did check that, the tank is pretty mint with no signs of rust. Comes from spending most of its life in USA. it does point to a float valve sticking but its not consistent one minute it drops what looks like a gallon of fuel then nothing or it could be dumping every 30 seconds. All this is when engine is ticking over on idle. Dont want to take carbs off just yet as they are not the easiest things to get on and off as we all know. I will check the float levels again today to see where we are at. keep the suggestions coming as Im fresh out of them
-
keith mayall
- 100Club
- Posts: 196
- Joined: 1st Jun 2014
- Location: MANCHESTER
these carb kits we buy have dodgy float valves in em it took me a few goes with swapping valves to stop the fuel ,in the end I put a old one back in,the spring inside the new ones was not smooth at all and one had no spring at all and these was new....pain in the backside with carbs in out in out,ect..goodluck
Had the same problem yesterday with my Z1R, number 1 carb, sticking valve, gave the bowl a few taps with a screwdriver butt, stopped it, I think the fuel gells in little blobbs when air gets to it, just put some in a tub and see after ten minutes! the tanks are always vented so air is there, or it could be a bit of crap, there should be a filter on the rubber tube, is on mine.
CB125 GT380 CB750F1 Z1R GPZ 750 Turbo Z1R
Are'nt these the carbs that split the vertical brass vent tube in the float bowls?
Withe regard to the above; i bought some new float needles with seats from NRP for the CV's.
Similar problem with intermittent flooding.
After a bit of close scrutiny i could see that the float needles were a mil or two shorter and the seats a mil or two longer.
(installed height would have worked out the same as original).
However the spring plungers were much softer than the originals and would easily bottom in the float needles.
At full float level, the needle would be further inside the brass seat and the tang on the float was contacting the outer rim of the seat stopping the needle from exerting any pressure at its tip on the seat orifice!
Parked them in the end and went back to the worn originals which were infinitely better by comparison.
In the final analysis my original problem turned out to be the 'O' rings round the seats where they press into the body.
These had shrunk / worn and were letting fuel round the outside of the seat!
AL
Withe regard to the above; i bought some new float needles with seats from NRP for the CV's.
Similar problem with intermittent flooding.
After a bit of close scrutiny i could see that the float needles were a mil or two shorter and the seats a mil or two longer.
(installed height would have worked out the same as original).
However the spring plungers were much softer than the originals and would easily bottom in the float needles.
At full float level, the needle would be further inside the brass seat and the tang on the float was contacting the outer rim of the seat stopping the needle from exerting any pressure at its tip on the seat orifice!
Parked them in the end and went back to the worn originals which were infinitely better by comparison.
In the final analysis my original problem turned out to be the 'O' rings round the seats where they press into the body.
These had shrunk / worn and were letting fuel round the outside of the seat!
AL
1981 J1
[quote="zorded"]Are'nt these the carbs that split the vertical brass vent tube in the float bowls?
Withe regard to the above; i bought some new float needles with seats from NRP for the CV's.
Similar problem with intermittent flooding.
After a bit of close scrutiny i could see that the float needles were a mil or two shorter and the seats a mil or two longer.
(installed height would have worked out the same as original).
However the spring plungers were much softer than the originals and would easily bottom in the float needles.
At full float level, the needle would be further inside the brass seat and the tang on the float was contacting the outer rim of the seat stopping the needle from exerting any pressure at its tip on the seat orifice!
Parked them in the end and went back to the worn originals which were infinitely better by comparison.
In the final analysis my original problem turned out to be the 'O' rings round the seats where they press into the body.
These had shrunk / worn and were letting fuel round the outside of the seat!
AL[/quote]Those other 28's that had the damaged emulsifying tubes are ok been on a ltd for a month now. Guy is going back to the original 26mm set as he just found out that the 28's came off a gs1000. someone told him that they wont run on a z1000. Dont know what he has been using for last month!!
What you and Keith say about the spring tension on the float valves makes some sense. When I replaced the mixture adjustment screw I noticed that the springs were a lot weaker, hence I put the old ones back in. I will take the bowl off the outer carb and change the float valve back to the old one. I will do a comparison check as well
Withe regard to the above; i bought some new float needles with seats from NRP for the CV's.
Similar problem with intermittent flooding.
After a bit of close scrutiny i could see that the float needles were a mil or two shorter and the seats a mil or two longer.
(installed height would have worked out the same as original).
However the spring plungers were much softer than the originals and would easily bottom in the float needles.
At full float level, the needle would be further inside the brass seat and the tang on the float was contacting the outer rim of the seat stopping the needle from exerting any pressure at its tip on the seat orifice!
Parked them in the end and went back to the worn originals which were infinitely better by comparison.
In the final analysis my original problem turned out to be the 'O' rings round the seats where they press into the body.
These had shrunk / worn and were letting fuel round the outside of the seat!
AL[/quote]Those other 28's that had the damaged emulsifying tubes are ok been on a ltd for a month now. Guy is going back to the original 26mm set as he just found out that the 28's came off a gs1000. someone told him that they wont run on a z1000. Dont know what he has been using for last month!!
What you and Keith say about the spring tension on the float valves makes some sense. When I replaced the mixture adjustment screw I noticed that the springs were a lot weaker, hence I put the old ones back in. I will take the bowl off the outer carb and change the float valve back to the old one. I will do a comparison check as well
all good now. Thanks for your help guysWho is online
Users browsing this forum: No registered users and 148 guests