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88VTZ
25th May 2011, 17:54
Hey Ive recently purchased a 1988 Honda VTZ250 and was wondering if anyone knows if the carbs are the same as the early VTR ones, ie will the dynojet kit fit? I found a number on em 10B[B]BF (middle B is in a rectangle) followed by a Japanese symbol that kinda looks like a J, but cant find info anywhere on the net about them.

Also does anyone happen to have a spare petcock valve that will work. Mine makes it damn hard to start the bike even if its been running the moment I hit reserve, also off position only seems to restrict the flow a bit.

Cheers

ducatilover
25th May 2011, 17:57
Are they Keihin carbs? And why are you wanting to re-jet it? I have some 96 and 98 Keihin jets here you could have if they are bigger than the originals.

The pet cock should be the same as VFR400R, CBR250RR, VTR/VT250 and VT250 Spada

88VTZ
25th May 2011, 18:11
Cheers, yea they are. Not wanting to replace them, just heard that they need re jetting if higher flow filter and exhaust are fitted. Not sure how much truth there is to that but want to know if the options available if it stops running right.

bogan
25th May 2011, 18:16
Not sure on your carbs, but I may have a spare petcock from an 86 VT250 at my parents, if that would work I could have a hunt for it.

ducatilover
25th May 2011, 23:29
Cheers, yea they are. Not wanting to replace them, just heard that they need re jetting if higher flow filter and exhaust are fitted. Not sure how much truth there is to that but want to know if the options available if it stops running right.
Have you got much in the way of mechanical know how? If so, you can re-jet them yourself. It's true, you will need to re-jet them with a higher flowing exhaust mod or air filter. I never found any real gains by fitting a higher flow filter to my VT250 Spada, less than a HP with jetting to suit on the dyno and less seat of pants torque.

Post a picture of the fuel tap and carbs if you can?

88VTZ
27th May 2011, 22:11
Ill try get some pics up tomorrow, the frame will make the carb pics a bit crap tho. Yea I've rebuilt the engine n gearbox in my car (GTO), just haven't worked with carbs yet. Im sure it'll make sense when I eventually pull one apart. Do you know if the stock jets are adjustable?

Cheers

ducatilover
27th May 2011, 22:37
Ill try get some pics up tomorrow, the frame will make the carb pics a bit crap tho. Yea I've rebuilt the engine n gearbox in my car (GTO), just haven't worked with carbs yet. Im sure it'll make sense when I eventually pull one apart. Do you know if the stock jets are adjustable?

Cheers
They aren't adjustable. I also have some 100 and 102s here with some 35 or 40 idle jets, will check if you want?
Keihin carbs are piss easy to work with. I was running 98 front and 100 rear on my VT250 Spada if my memory serves me correct an 120/122 with nitro methanol.
If you can rebuild a 6A13 and which ever gearbox you have (Both are pricks) then a VTZ will be a walk in the park.


Edit, if they're the carbs I am thinking of, pull them off, you don't have to disconnect the throttle or the choke to re-jet, drain the bowls, take the carb bowls off, your main jet will be the larger and closest to the bottom of the bowl, it'll be a circular bit of brass that screws into a longer tube (Emulsion tube), put an 8mm spanner on the emulsion tube to hold it steady and use a flat head (It's obvious when you have them apart) to un-screw the jet. Depending on year of manufacture the jet will have a number written on either the side or top Eg: a "98" will have 98 or 098 written on it. If you find the jet sizes and tell us, I may have some here that will suit, hopefully. With the idle jets, they will be beside the main jets you have pulled out and will not protrude as far. If they are the alternate model carbs, the pilot/idle jets will be recessed in a housing, but are easy to get out with a small screw dirver, just be sure you don't lose any O-rings.


Good luck bro.

88VTZ
31st May 2011, 22:34
It's one of the newer turbo GTO's so 6g72 and Getrag box, wasn't easy

I finally got round to getting the photos. Carb ones aren't the best koz the frame was blocking the shot.

http://s1184.photobucket.com/albums/z338/euan9/

Could be a couple of weeks until i get around to puling them. Would definitely be keen for the jets if they'll fit.

Cheers

ducatilover
31st May 2011, 23:24
It's one of the newer turbo GTO's so 6g72 and Getrag box, wasn't easy

I finally got round to getting the photos. Carb ones aren't the best koz the frame was blocking the shot.

http://s1184.photobucket.com/albums/z338/euan9/

Could be a couple of weeks until i get around to puling them. Would definitely be keen for the jets if they'll fit.

Cheers
Oops, got confused between the 6g and 6a, the 13 was the 2.5 in the Galant/Legnum

They look like they have the Keihin symbol on them and if they're the same series as I am thinking of then they will have the 393 series jets that I have.

Let us know when you get her apart

Insanity_rules
1st June 2011, 08:12
There were two very different carb setups for the VTZ that I have seen. One is almost identical to the 89 Spada, the other is VT250 (I think FD???). Cam chains and stuff go for econo honda, those guys rock. They might be able to help you identify which carb setup you have too.

Linky http://www.econohonda.co.nz/