TU250 - Page 3

alantf · 09-20-2009, 04:59 AM

Quote:

Originally Posted by alanmcorcoran

I wish the GZ had the fuel injection. The carb/choke/idle seems to be a common source of sporadic irritation on an otherwise cleanly engineered entry level bike.

O.k. ......... I'm no engineer -but - (leaving the cost aside for the moment) would it be possible to buy & fit the injector system of the TU250 to the GZ? If it were possible, do you reckon that it would make any noticable difference to the performance? Like I said elsewhere, the GZ fits my needs perfectly, so if fitting the FI was possible, & made a difference to top speed, I'd sooner go for this than change the bike. :jo:

**jonathan180iq** · 09-22-2009, 02:26 PM

Someone needs to get a hold of the TU250 service manual and cross reference the differences, if any, that exist between the basics of these engines. If they are indeed the same, then you should be able to shoehorn in the electronics of the injection system. I mean, if we are dealing with a straight engine clone, I don't see why it wouldn't be possible.

Someone just needs to do it...

bonehead · 09-22-2009, 02:57 PM

Quote:

Originally Posted by jonathan180iq

Someone needs to get a hold of the TU250 service manual and cross reference the differences, if any, that exist between the basics of these engines. If they are indeed the same, then you should be able to shoehorn in the electronics of the injection system. I mean, if we are dealing with a straight engine clone, I don't see why it wouldn't be possible.

Someone just needs to do it...

TAG, you're it.

dhgeyer · 09-22-2009, 11:56 PM

For starters the TU has only 2 valves, whereas the GZ has 4. The cylinders look quite a bit different. The tank is different, and the TU has no fuel shut off valve, since it has a fuel pump instead. I suppose you could just rig a line to the fuel pump from the the valve on the GZ and leave it on PRIME all the time. So, at a minimum you would need to buy the fuel pump, the throttle body with injector and TPS (throttle position sensor), and an ECU (electronic control unit). You would have to hope that the connections from the TU's throttle body is consistent with the ones on the GZ's carburator, going to the engine and the airbox, and that the new components would fit in the shorter GZ frame. And, along with the different valve setup and different airbox and filter, you would have to hope the ECU would be able to function at all in the different environment. Might need a different throttle cable. The TU has a catalytic converter, and is a closed loop EFI system, complete with an O2 sensor. The EFI probably wouldn't work properly without the input from the O2 sensor, so you'd have to somehow rig a TU exhaust system to the GZ, or else rig up some electronics to mimic the input from the O2 sensor. People actually have done this to some of the early oilhead Beemers because some of them ran very badly from the factory, and it was discovered that taking the real O2 sensor out of the loop and mimicing its input solved the problem. Way over my head electronically. If you tried to rig a TU exhaust to the GZ you would need to deal with the fact that the GZ has a 2 into 1 system, whereas the TU has a single pipe from the head, and it's a larger diameter. Then you would have to hope that the ignition control in the TU's ECU would properly control the ignition on the GZ, with correct timing and so forth. Probably wind up needing a TU ignition setup right out to the spark plug wire.

When all is said and done, I think it would be easier to just buy a TU250. I'm pretty sure there is one in my (hopefully) not too distant future. I'd trade up tomorrow, but I have this problem. My daughter, who rides, has fallen totally in love with the GZ. I bring up the TU once in a while, but she insists that she's "not ready to break up" with the GZ yet. Like it's a friggin boyfriend or something! Anyway, I can't break her heart, so the GZ stays for a while. Can't see the TU and the GZ along with 2 other bikes, so I'm stuck for now. Damn!

gripped · 09-23-2009, 02:21 AM

Quote:

Originally Posted by dka67x

New poster here. Not a GZ250 owner but a new TU250 owner. I bought the TU250 to turn it into a cafe racer. Below are pics of my little TU cafe racer. I know it will never be a true racer but I love the look of the bike. I hope you all like it as well.

Thanks

:2tup: :2tup: :rawk: :rawk: YEAH! You beat me to it!!!

**jonathan180iq** · 09-23-2009, 08:49 AM

Quote:

Originally Posted by bonehead

Quote:

Originally Posted by jonathan180iq

Someone needs to get a hold of the TU250 service manual and cross reference the differences, if any, that exist between the basics of these engines. If they are indeed the same, then you should be able to shoehorn in the electronics of the injection system. I mean, if we are dealing with a straight engine clone, I don't see why it wouldn't be possible.

Someone just needs to do it...

TAG, you're it.

I may have once been that guy.

I'm no longer that guy.

bonehead · 09-23-2009, 11:08 AM

Ya, I' done with the mods. When I need it to go faster I'm just going to remove the gas cap and drive something bigger underneath it.

**jonathan180iq** · 09-23-2009, 03:49 PM

I don't even own a GZ.

When I upgraded, I actually downgraded to 150.

dannylightning · 09-23-2009, 08:05 PM

Quote:

Originally Posted by dka67x

New poster here. Not a GZ250 owner but a new TU250 owner. I bought the TU250 to turn it into a cafe racer. Below are pics of my little TU cafe racer. I know it will never be a true racer but I love the look of the bike. I hope you all like it as well.

Thanks

]

DUDE!!!! that is killer, i really, really don't like the look of those bikes but you have done something completely awesome to that thing.
that is the coolest little 250CC bike EVER!!

dka67x · 09-24-2009, 11:16 AM

Thanks to all who liked my cafe racer. I appreciate the comments.

To those who are looking to install FI on the GZ, I have the service manual and I will try to post the info on the TU250 FI set up.

And to the original intent of this thread, I hope there will eventually be a TU250 section. I think there is a growing number of us to TU owners. Thanks to the GZ250 owners for letting us hang out here

09-22-2009, 02:26 PM	#22
jonathan180iq Super Moderator Join Date: Jan 2007 Location: Dalton, GA Posts: 3,996	Re: TU250 Someone needs to get a hold of the TU250 service manual and cross reference the differences, if any, that exist between the basics of these engines. If they are indeed the same, then you should be able to shoehorn in the electronics of the injection system. I mean, if we are dealing with a straight engine clone, I don't see why it wouldn't be possible. Someone just needs to do it...
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09-22-2009, 11:56 PM	#24
dhgeyer Senior Member Join Date: Jul 2009 Location: Merrimack NH USA Posts: 722	Re: TU250 For starters the TU has only 2 valves, whereas the GZ has 4. The cylinders look quite a bit different. The tank is different, and the TU has no fuel shut off valve, since it has a fuel pump instead. I suppose you could just rig a line to the fuel pump from the the valve on the GZ and leave it on PRIME all the time. So, at a minimum you would need to buy the fuel pump, the throttle body with injector and TPS (throttle position sensor), and an ECU (electronic control unit). You would have to hope that the connections from the TU's throttle body is consistent with the ones on the GZ's carburator, going to the engine and the airbox, and that the new components would fit in the shorter GZ frame. And, along with the different valve setup and different airbox and filter, you would have to hope the ECU would be able to function at all in the different environment. Might need a different throttle cable. The TU has a catalytic converter, and is a closed loop EFI system, complete with an O2 sensor. The EFI probably wouldn't work properly without the input from the O2 sensor, so you'd have to somehow rig a TU exhaust system to the GZ, or else rig up some electronics to mimic the input from the O2 sensor. People actually have done this to some of the early oilhead Beemers because some of them ran very badly from the factory, and it was discovered that taking the real O2 sensor out of the loop and mimicing its input solved the problem. Way over my head electronically. If you tried to rig a TU exhaust to the GZ you would need to deal with the fact that the GZ has a 2 into 1 system, whereas the TU has a single pipe from the head, and it's a larger diameter. Then you would have to hope that the ignition control in the TU's ECU would properly control the ignition on the GZ, with correct timing and so forth. Probably wind up needing a TU ignition setup right out to the spark plug wire. When all is said and done, I think it would be easier to just buy a TU250. I'm pretty sure there is one in my (hopefully) not too distant future. I'd trade up tomorrow, but I have this problem. My daughter, who rides, has fallen totally in love with the GZ. I bring up the TU once in a while, but she insists that she's "not ready to break up" with the GZ yet. Like it's a friggin boyfriend or something! Anyway, I can't break her heart, so the GZ stays for a while. Can't see the TU and the GZ along with 2 other bikes, so I'm stuck for now. Damn! __________________ 54 HD Hummer,64 Honda150,66 Ducati250,01 Vulcan500,02 Vulcan1500,83 Nighthawk650,91 K75,95 VLX,04 VLX,01 GS500E,01 Ninja250, 02 Rebel,04 Ninja500,06 Concours,96 R850R
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09-23-2009, 11:08 AM	#27
bonehead Senior Member Join Date: May 2009 Location: elgin,tx Posts: 907	Re: TU250 Ya, I' done with the mods. When I need it to go faster I'm just going to remove the gas cap and drive something bigger underneath it. __________________ Standing with the PGR until they stand for me.
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09-23-2009, 03:49 PM	#28
jonathan180iq Super Moderator Join Date: Jan 2007 Location: Dalton, GA Posts: 3,996	Re: TU250 I don't even own a GZ. When I upgraded, I actually downgraded to 150.
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09-24-2009, 11:16 AM	#30
dka67x Junior Member Join Date: Sep 2009 Location: Frisco, TX Posts: 4	Re: TU250 Thanks to all who liked my cafe racer. I appreciate the comments. To those who are looking to install FI on the GZ, I have the service manual and I will try to post the info on the TU250 FI set up. And to the original intent of this thread, I hope there will eventually be a TU250 section. I think there is a growing number of us to TU owners. Thanks to the GZ250 owners for letting us hang out here
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