Motorcycle Repair/No power


QUESTION: Hello, you helped me before with electrical issues. Anyway, this is not an electrical issue. Now it is an air filter question. I replaced the stock air filter with a high performance K&N air filter. I just now am hearing that my bike is running lean because the high performance air filter is intaking more air than fuel thus creating a lean issue. Is this true? if so, can i simply go back to stock or is that to late now that i been running on the high performance air filter?

ANSWER: Hello Robert and welcome back,

You have nothing to worry about, as for the air filter.

Your bike's fuel injection utilises an IAP (Intake Air Pressure) sensor, thus calculates and adjusts fuel delivery according to the air flow in the intake manifold.

The ECU is programmed to compensate intake air mass variations, due to altitude, barometric changes, air filter condition (from new to clogged).

Consequently, the air-to-fuel ratio is constant (at least no leaner than the factory setting) and safe for your engine's health, so ride care-free!

Season's Greetings and Best Regards,
Lazaros Ampatzidis.

P.S.:The person who told you about a lean issue, probably had the carburetted model in mind.

---------- FOLLOW-UP ----------

QUESTION: Hello.. My motorcycle sounds like a sewing machine, I'd like to have it sound more like a motorcycle, of course i know of exhaust systems etc, right now, it's a budget issue for me. I also read of and inquired of having the baffels removed, I heard the pro and cons..

i need to ask the expert.

Can I remove the baffels without having to add a power commander or will it be something i must need if i did so..

Again.. Thank you for all your advice, help..

ANSWER: Hello again Robert,

I NEVER recommend tampering with the stock exhaust silencers, because the result is unpredictable.
An aftermarket system is compensated by the various ECU sensors, but modifying the factory one may cause unwanted side-effects and situations that the FI system can't handle.

To evaluate and properly tune the bike after removing the baffles, will probably cost you more than to buy branded competition exhaust, which will be "bolt-on" and require no additional tuning.

On the other hand, if you know an exhaust technician who can properly modify and not just remove the baffles, and guarantees the result, then go ahead.

Season's Greetings,
Lazaros Ampatzidis.   

---------- FOLLOW-UP ----------

QUESTION: Hello, long time.. I have a 2006 boulevard c50.. well as you can see from our earlier conversations, it is still electrical i think. anyway, my bike has been running well, still had to turn the ignition switch quite a few times in colder days but on warmer days, it would just come on like nothing wrong. Well until yesterday.. i went riding, the bike was doing fine, arrived at a friends house then a few hours later it was time to leave, then as i got on my bike, i looked at my speedometer of my bike, i never seen the needle that way down, like it was broke just hanging there (the speed indicator stick). sure enough, it did not come on at all.. no power, no nothing.. just dead.. what can it be?

Hello Robert,

It's always a pleasure to see returning "customers".

As for your electrical issue,it seems we are back to the beginning.
My advice is to roll back and carry out the tests and measurements I mention in my first answer and on.

The speedo pointer position, is due to power fluctuations. It is driven by a stepper motor, which can stop at any point, when an abnormal voltage is applied.

Start from the battery terminals and the main power feed/fuse on the starter relay (

Best Regards,

P.S. : Open a new question, to avoid excessive follow-ups, if/when you come back.

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Lazaros Ampatzidis


I can help you on EVERY issue involving POST-1980 Japanese Motorcycles plus KTM and Husaberg. My field of expertise includes Engine, Transmission, Fuel system (carburation & EFI),Electrics and Electronics. Maintenance, repair and tuning. Road and off-road suspension tuning. Please don't ask me about non-Japanese Motorcycle, especially American built on which I have low to zero experience.


I'm a rider and hobbyist since childhood. 25 years motorcycle workshop mechanic.15 years motorcycle racing mechanic. In order of experience high to low:Kawasaki,Suzuki,Honda,Yamaha,KTM,Husaberg.

Hellenic (Greek) Technical School.Internal Combustion Engines Engineer. Automotive Electronics.

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