Finally MOT on Thursday and TPS Adjustment

Hi All.

At last I have got my bike back together and it is booked in for an MOT on Thursday. I have not ridden it since the end of April when I broke a bolt in the cylinder head trying to take the exhaust off. Sunday's good weather allowed me to get out there and finish all the work.

The bike is now gleaming as well, so I hope this bloody rain stops.

For anybody who is interested, I did the TPS adjustment some time ago. At the weekend I balanced the throttle bodies. All I can say is don't bother with the TPS adjustment until you have balanced the throttle bodies. Mine were way out. It took about 3/4 of a turn of the balance screw to bring them back in line. I then re-checked the TPS adjustment and this needed adjustment again.

I made my own balance gauge. I used about 8 feet of clear polypipe about 5mm I/D. I had already connected about 10" of 3.5mm clear polypipe on the vacuum nipples. I then got about a 6 foot length of 2" x 2" wood which I had laying around and looped the pipe arond the bottom and used tape to run the two columns of pipe up the length of wood for about 3 to 4 feet. I then poured Glow Fuel into the pipe up to about 1 foot each side. (I used glow fuel because it was to hand, light oil will do). While starting the bike I pinched the pipes so it would not suck up the liquid. I had previously warmed the bike up. I then released the pinches in the pipes and hey presto. All I can say is this home made gauge is really sensitive. It only took the slightest movement of the balance screw for the column to move one way or another. You can keep your Carbtune units @ £55 a time. It would be so easy to make one for 4 cylinder bikes as well with some T pieces.

All I can think is that the balance was off from the factory or the previous owner had some work done and they were not set correctly afterwards.

Well worth it, slow speed seems a lot smoother now.

Roll on Thursday.

Tim

Originally Posted by I'm_a_Newbie

Hi All.

At last I have got my bike back together and it is booked in for an MOT on Thursday. I have not ridden it since the end of April when I broke a bolt in the cylinder head trying to take the exhaust off. Sunday's good weather allowed me to get out there and finish all the work.

The bike is now gleaming as well, so I hope this bloody rain stops.

For anybody who is interested, I did the TPS adjustment some time ago. At the weekend I balanced the throttle bodies. All I can say is don't bother with the TPS adjustment until you have balanced the throttle bodies. Mine were way out. It took about 3/4 of a turn of the balance screw to bring them back in line. I then re-checked the TPS adjustment and this needed adjustment again.

I made my own balance gauge. I used about 8 feet of clear polypipe about 5mm I/D. I had already connected about 10" of 3.5mm clear polypipe on the vacuum nipples. I then got about a 6 foot length of 2" x 2" wood which I had laying around and looped the pipe arond the bottom and used tape to run the two columns of pipe up the length of wood for about 3 to 4 feet. I then poured Glow Fuel into the pipe up to about 1 foot each side. (I used glow fuel because it was to hand, light oil will do). While starting the bike I pinched the pipes so it would not suck up the liquid. I had previously warmed the bike up. I then released the pinches in the pipes and hey presto. All I can say is this home made gauge is really sensitive. It only took the slightest movement of the balance screw for the column to move one way or another. You can keep your Carbtune units @ £55 a time. It would be so easy to make one for 4 cylinder bikes as well with some T pieces.

All I can think is that the balance was off from the factory or the previous owner had some work done and they were not set correctly afterwards.

Well worth it, slow speed seems a lot smoother now.

Roll on Thursday.

Tim

HI Tim,
Sorry but I didn't understand that. Can you post up a diagram of what you did - how it's connected up?
Thanks
John

[Stu]

Originally Posted by ejohnh

HI Tim,
Sorry but I didn't understand that. Can you post up your address and I come round and watch you Thanks
Stuart

That's more like it!

[Sid Squid]

Originally Posted by I'm_a_Newbie

For anybody who is interested, I did the TPS adjustment some time ago. At the weekend I balanced the throttle bodies. All I can say is don't bother with the TPS adjustment until you have balanced the throttle bodies. Mine were way out. It took about 3/4 of a turn of the balance screw to bring them back in line. I then re-checked the TPS adjustment and this needed adjustment again.

Yes well it would wouldn't it? The balance screw adjusts the relative positions of the butterflies, the throttle stop is on the front cylinder and the TPS on the rear, if you change the balance the TPS position is changed in relation to the tickover stop.

This kind of thing? How hard was it to make?

Originally Posted by SV225

This kind of thing? How hard was it to make?

Thanks,
That looks quite clear.
John (I think Stu still wants to come round though )

Originally Posted by SV225

This kind of thing? How hard was it to make?

That's exactly the kind of thing. You don't need to ruler though, it is easy to see when the fluid is level.

The 3.5mm pipe I had already fitted to the vacuum nipples pushed inside the larger bore pipe I used for the gauge so making an air tight seal.

When I had finished the balancing, I plugged the ends of the pipes on the bike and used a cable tie to fix them against the wiring loom so they are already there for future use.

Tim.