EFI for Bajaj Pulsar 150cc Motorcycle

I am working on build up of BAJAJ Pulsar 150 dtsi model for EFI Conversion. The Motorcycle is considered to be most rugged two wheeler when compared to other brands in India. I have one which is almost 9 years old and the engine needs an overhaul (which i would be doing it soon ) .The Company has recently confirmed an EFI Model which is yet to be available in the market.

The carburetted version specs for the model are ,


  • Type Single cylinder, 4 stroke, air cooled, DTS-i ( Intelligent Digital Twin Spark )
  • Bore (mm) X Stroke (mm) 58 X 56.4
  • Displacement (cc) 149
  • Fueling : Carburetor (Ucal - Mikuni BS 26)
  • Compression ratio 9.5 (+ 0.5) : 1
  • Max. Power (Ps @ rpm) 15.06 @ 9000
  • Max. Torque (NM @ rpm) 12.28 @ 6500
  • Starting Kick + Self


Clutch Wet multiplate
No. of gear & pattern 5 (All down)
Primary reduction 3.47
Final reduction 2.8
Gear ratio
First 2.92
Second 1.88
Third 1.38
Fourth 1.08
Fifth 0.92


Type Double cradle downtube
Front Telescopic
Rear Nitrox hydraulic shock absorber
Front Disc (240 mm)
Rear Drum(130 mm)
Front 2.75 X 17"
Rear 100 / 90 X 17"
Fuel tank capacity 15 liter full; 3 liter reserve


Overall Length (mm) 2000
Overall Width (mm) 790
Overall Height (mm) 1065
Wheel base (mm) 1320
Ground Clearance (mm) 165
Kerb weight (kg) 137


Battery (Voltage & current) 12v, 9Ah
Head lamp (wattage) 35 /35
Tail / stop lamp 5 / 21
Horn DC, 2 numbers

I am planning to have a long tour of around 6K Kms with terrain ranging from coastal to one of the highest altitude pass in the world on it after restoring the model and replacing the carb with NonoEFI.

Being an Embedded Software Developer , I have been working to add Block and Oil Temprature with O2 sensors on the Bike. I hope the Test would be one of the toughest of the NanoEFI.

Welcome, bnm95.

I think that the biggest thing Travis will want you to add here is what your generator output is. Other circuit diagrams would be helpful as well if you have them (from the manual, for example).

Do you have any pictures of this rugged machine?

Thanks! ,Here are some pictures,


The electrical system is 12V(AC+DC) .The exact charging system specs are not available right now , I will upload it as i load test the alternator. I also have workshop manual , but there is less of electrical description and more of mechanical system. I will upload that later if required.


Here’s the wiring diagram,

Welcome @dnm69! :wave:

Great bike! Do you know if your Pulsar 150cc is a variant of the CG engine platform? Looks similar, but I’m unable to find a close-up online that’s good enough to tell.

That would be the most helpful right now. We need to know the capacity of your charging system while the engine is idling.

Hi Travis,
Dts-i engines are not based on CG Engines , there is another Indian company named Hero which had collaboration with Honda and has CG platform engines.


As of the Alternator output , at idle engine speed (800-1000) rpm , 18-20 AC Volts are generated with 13.5 to 14.2 Volts rectified DC ( without Illumination lamps and Headlight load apart from battery ) from the regulator to charge the 12V 9ah battery. with all the loads , it goes down to 13-15V AC with little fluctuation in rpm. Please add if I am missing something in the test.

Ultimately, what we really need to figure out is what the available wattage at idle is.
It sounds like your electrical system is working currently with the current load, but we need to be able to add some additional load and that still be the case.
Hopefully @TravisNano has some shadetree ideas how this might easily be done, but in my own experience, the only idea i have would be to wire up a known load (light bulbs or something similar) and see how many watts of load you can add to the system and keep voltage (read at the battery terminals) at idle above 12.5 or so indefinitely.
They make load testers, but i didn’t find any particularly cheaply.
Basically, what we’ll need to know is how much excess amperage (and thus wattage) your charging system can develop at idle.

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It sounds like his system is a single phase ac, with dc primary source coil for the cdi ignition. your regulator is only half bridge rectified. one coil produces 12- the other side 12+. Those system put out very little wattage under 1500-2000 rpm. Basically enough to run lights and keep the battery from draining.
If he was to support EFI and other accessories he will have to either convert to three phase ac which can provide 2-3x as much energy even at idle.

Realistically, your alternator is putting out probably around 7-8 volts at idle, only maybe 12 watts. then it will climb to nearly 18 v at full throttle, but the regulator shunts the rest off to keep it down at 14.7 to keep the battery happy.

I am currently working on the alternator setup for my XS650. The factory setup had a field regulated output so it only produced what it used. A PMA type produces all the time. I am going to use a mosfet full bridge rectifier/regulator. ac to dc. That will go straight to a battery. You would have to get a different ignition controller because your bikes CDI ignition box uses the primary coil in your stator to fire the coil.

@dnm69 Could you upload a few pictures of your regulator/rectifier unit? And your stator if it’s not too much trouble. Thanks.

Google seems to suggest that the Pulsar 150 uses an 8-pole stator. What I’m seeing actually looks like a direct match to the GY6 8-pole, which would be great news.

If true, that would mean that an 11-pole GY6 stator may bolt right in, and likely fit the existing flywheel as well. NanoEFI was born out of the GY6 platform, so if your machine is compatible with the same upgrades it’ll go a long way towards a solid nEFI installation.


That’s not a problem. NanoEFI can currently manipulate the trigger of both AC and DC powered CDIs.

I recommend using the official CDI included in the nEFI kit though. It’s intentionally just a common standard DC CDI and nothing proprietary (so we’re not bloating kit costs for no real reason). However, its timing profile will be known and mapped in the ECU ahead of time. Keeps things simple on install.

A post was split to a new topic: Can NanoEFI drive both AC and DC CDIs?