[bikertillidie]

Commenced work on converting my UCE500 Classic from EFI to a carburettor based set-up.

Items procured -

(a) BS32 carburettor meant for Pulsar 220
It comes with 15 & 115 sized jets (pilot & main respectively) by default

(b) Jets sized 125 & 130 as replacement main jets for the BS32 carburettor

(c) Accelerator cable for the classic 350 (to replace the existing twin cable set-up of the Classic 500)

(d) Rubber flange for mounting the new carburettor

(e) Pentagon shaped flange for mounting a fuel tap from a thunderbird

(f) Fuel tap assembly from a classic 350

(g) Hex socket headed screws 2 * M6 x 1 x 14 (the ones procured were a bit longer)

The pentagon shaped flange had a few odd protrusions jutting out, which would have otherwise interfered with the frame & battery cover during fitment. Hence, they had to be sawed off. The burred edges were attended to with a file.

Here are a few pictures from yesterday afternoon.







The screws for mounting the fuel tap were a tad loger than required. Had to shorten them by about 10 mm.




The flange holding the injector and the throttle body were removed after disconnecting the choke & accelerator cables (and disconnecting all couplers).

To be continued this evening as well -

[rakesh_r]

@bikertillidie-excellent stuff. I too am pissed off with my 4 month old 3 k run DS with the jerking issue.
One query-Is the carb from the B500 and the p220 the same?If no why didn't you opt for the B500 carb?

[bikertillidie]

Originally Posted by rakesh_r

@bikertillidie-excellent stuff. I too am pissed off with my 4 month old 3 k run DS with the jerking issue.
One query-Is the carb from the B500 and the p220 the same?If no why didn't you opt for the B500 carb?

Hi Rakesh,

The carbed version of the UCE bullet 500 uses a UCD33 carb.

Older LB500s used a BS29 carb, if I am not mistaken.

The primary reason I did not opt for the UCD33 carb is cost.

The BS32 carb from a pulsar 220 costs roughly half that of a UCD33 and I am hoping that with an up-rated main jet (cost 60 INR), it should provide roughly the same performance.

[ilangop]

Originally Posted by bikertillidie

Commenced work on converting my UCE500 Classic from EFI to a carburettor based set-up.

Neat work. Didn't expect that you will get into action so soon . Eagerly waiting for your road test report.
Is the carb flange from AVL thunderbird?

[bikertillidie]

Ilango, many thanks !

I was inspired by your previous post
The carb flange is from a carbed version of the UCE 500 (going by the part number from the spare parts catalogue).

It may fit the thunderbird as well, but am not sure.

[ebonho]

Originally Posted by bikertillidie

The carb flange is from a carbed version of the UCE 500 (going by the part number from the spare parts catalogue).

Seeing as you are a Puneite, I have a fair idea of the hoops you must have jumped through to do what you have done, hence my appreciation. In addition to the DIY as well of course.

Where exactly did you get the individual parts from?

[bikertillidie]

Originally Posted by ebonho

Seeing as you are a Puneite, I have a fair idea of the hoops you must have jumped through to do what you have done, hence my appreciation. In addition to the DIY as well of course.

Where exactly did you get the individual parts from?

Hi Ebonho,

Thanks!
Yes, I did do my usual rounds at authorised service centres.

The carb & replacement main jets were procured from Nanapeth.

Remaining spares were procured from a friendly RE spare parts distributor in the Hadapsar area, who also provides a fair discount off MRP pricing.

[bikertillidie]

Reached home late last evening. Hence, could manage only the following -

• The carb has been bolted on.
• The accelerator cable was also replaced.

Attachment 1379939




I need to procure a few jubilee clips to mount a rubber bellow between the air filter intake & the carb.
I thought I had a few spare ones at home, but couldn't locate them last evening.



Checked out the potentiometer readings from the TPS. It varies from about 1.5 Kilo-ohms to approximately 4.5 Kilo-ohms.




Additional procurements needed

• a few cable ties
• relays
• T connectors
• switch for activating the choke

[ilangop]

Originally Posted by bikertillidie

BS32 carburettor meant for Pulsar 220
It comes with 15 & 115 sized jets (pilot & main respectively) by default

You will need a 20 - 25 pilot jet. Which you will understand why, once you try to tune the carb.
Hope you are aware of the tuning procedure for the fuel screw in BS carbs.

Still I am elaborating it for the novice here.
The pilot has to be chosen such that you can lean - rich - and over rich at idle at various positions of turning the fuel screw.
When the engine is warm, you have to start with the tightening the fuel screw till the engine rpm just drops.
As you unscrew the rpm tends to rise. While counting the no of turns, unscrew till the rpm falls again.
Now tighten it again by half the number of turns you had counted.
With #15 the engine will always run lean. (We experienced this is CI350 with BS32).
The #25 pilot from VM24 or #30 from VM28 will fit and solve your problem.
By looks the pilots looks little different in BS & VM carbs, but they do the job.

Originally Posted by bikertillidie

Additional procurements needed

• switch for activating the choke

What have you got in your mind for the switch.
You may use the horn dipper switch of Rajdoot or else buy a switch from
www.aliexpress.com

[bikertillidie]

Originally Posted by ilangop

You will need a 20 - 25 pilot jet. Which you will understand why, once you try to tune the carb.
Hope you are aware of the tuning procedure for the fuel screw in BS carbs.

Still I am elaborating it for the novice here.
The pilot has to be chosen such that you can lean - rich - and over rich at idle at various positions of turning the fuel screw.
When the engine is warm, you have to start with the tightening the fuel screw till the engine rpm just drops.
As you unscrew the rpm tends to rise. While counting the no of turns, unscrew till the rpm falls again.
Now tighten it again by half the number of turns you had counted.
With #15 the engine will always run lean. (We experienced this is CI350 with BS32).
The #25 pilot from VM24 or #30 from VM28 will fit and solve your problem.
By looks the pilots looks little different in BS & VM carbs, but they do the job.

Thanks.
I will check whether the pilot jets are available locally.

Originally Posted by ilangop

What have you got in your mind for the switch.
You may use the horn dipper switch of Rajdoot or else buy a switch from
www.aliexpress.com

This is what I have picked up. Would look more appropriate on a vintage bike though ...

[bikertillidie]

The bellow was fixed last evening. The switch has also been mounted on the handlebar. I have also started wiring up the relays.

[ilangop]

Originally Posted by bikertillidie

The bellow was fixed last evening. The switch has also been mounted on the handlebar. I have also started wiring up the relays.

What is the relay doing there?

[bikertillidie]

The relays are meant to emulate the fuel pump and the injector. I don't want the MIL lamp to blink continously.

[bikertillidie]

At last, the conversion is complete. The bike feels like it's on steriods

Acceleration is crisp, there was no hesitation/jerking evident during a test ride a short while ago.

I attach a few pictures taken earlier -

Connectors for
(A) For the fuel pump



(B) For the injector



(C) For the solenoid operated choke




T connector & tubing from a nearby store which sells aquariums
This was used for tapping into a tube leading to the PCV valve.




0.3 mm drill bits to alter the size of the pilot jet (just in case)!
Thankfully, it wasn't necessary.



An adapter was prepared for the MAP sensor and proper sealing was ensured with silicone sealant.






The relays were tucked away inside the tool box.



All the wiring & connectors were wrapped with insulation tape and cable ties were used to tuck everything away neatly.






Notice that the MIL light turns on (when ignition is turned on) & then goes off after a few seconds.





Finally, the sooty spark plugs were cleaned and gaps readjusted.
At last, the bike was ready.

[GTO]

Bikertillidie, thanks for sharing! Have moved your EFI -> carburettor conversion posts to a new thread.

This one is going straight to the homepage