Re: Suzuki Gixxer 155

When you cross from 2k to 4.5k rpm did you feel like your bike is trying hard to move past that rpm range?

I thought something was blocking the air filter but nothing was there... When the bike crosses 5k rpm, she behaves in a very different way..

Re: Suzuki Gixxer 155

I have not noticed such... I did not look into the cluster for that much detail.

But my friend who bought a trigger recently has made a thorough comparison of both bikes.

And according to him, gixxer seems to develop power at relatively lesser rpm than trigger.

He said a notable 500rpm difference.

Re: Suzuki Gixxer 155

60 is achieved at 4000rpm in gixxer. And trigger required 4500rpm to do the same.

And this means gixxer has more power in lower rev ranges right?

Correct me if I am wrong.

Re: Suzuki Gixxer 155

The gixxer does develop more power at lesser rpm ..
Can someone here make this small check so that I can understand if its just the bike's way of responding to the throttle?
I would need you to run your bike at a constant 3k rev range for 300 or 500 meters in the 4th or the 5th gear and then open the trottle..
I would require you guys to observe if there is a blocking effect or lagging effect when achieving higher rpms.. I would really appreciate this help..
With this I can diagnose what is going wrong..

Re: Suzuki Gixxer 155

Gixxer has a long stroke engine.Due to which when you are on lower rpm and suddenly twist your rpm it would require upto 4sec time to cope up with high rate of incoming fuel/air to be burned properly, but after that the rpm would rise linearly. This effect is less in over square engines such as ktm dukes,or Apache's

Re: Suzuki Gixxer 155

[MENTION=35827]shubhamt[/MENTION]iger... Thanks for your response ..I was owning an R15 v2 before.. I never faced an issue like that.. So i thought something was off. Your response gave a very good idea on whats goin on
Long stroke = more torque. I heard that the Gixxer does 60 in 4.4 sec.. Havent tested it yet..
Does this concept of delay in achieving high rpms Affect the acceleration?
Thanks again (Y)

Re: Suzuki Gixxer 155

Acceleration depends on your engine configuration and gear ratios. Long stroke engine can have good acceleration for example r15 has a bit of long stroke engine and best acceleration in 150 cc segment. So does the gixxer if you keep the gearing proper.

Re: Suzuki Gixxer 155

What did you do with the Yamaha R15 v2?
What's the ODO reading on GiXXeR-155?

Re: Suzuki Gixxer 155

Pictures of yesterday night trip...

Re: Suzuki Gixxer 155

I sold my yammie..
In hopes of getting duke 390 and i ended up getting the gixxer cause of my parents..
They didn't want me to spend more than a lakh once again or a sport bike.. Instead they insisted on me to get a car.. :P and I don't like to ride cars as much as I like to ride a bike [MENTION=36366]SparKot[/MENTION] I havent connected the cable to speedo..
The speedo is still dummy.
But the tacho is still active.
But my yammie had a 63mm uma racing block, a polished head and a 10 port injector coupled with a uma racing ecu.


I may have covered around 400 kms on the gixxer.. Took her to tada falls twice.. And then for sometime I was just roaming on the streets [emoji38] [MENTION=23608]Shubham[/MENTION] ... So which rpm range according to you would be the best to achieve the maximum acceleration the bike could produce?
Thanks again for your responses..
Much appreciated

Re: Suzuki Gixxer 155



I do not own a gixxer but I have experienced the same 'lag' on opening the throttle in my dio and rtr180. This is not due to engine characteristics but it is due to bad tuning of the carb. If your bike is running lean then at lower rpms, when you open the throttle, there is not enough fuel to burn and this causes a momentary lag which can be experienced only at lower rpms.
I read that you are coming from a r15; the r15 has an ecu which maintains the optimum air fuel ratio at all rpms and hence you would never have felt this lag on r15, but on carburetted bikes like gixxer, rtr etc, there is a fuel screw which regulates the amount of fuel going into the engine. You need to make the air fuel ratio richer by turning the fuel screw located on the carb in anticlockwise direction by about 1/4 to 1/2 a turn.
This is a trial and error method where you turn the screw then ride around for a day then depending the performance tune it again till you obtain the optimum ratio. Once you feel you have obtained the optimum ratio, remember the number of turns of the screw from its fully closed position in case the tuning gets messed up in future.
A few points to remember are:
1. Always tune the carb when the engine is hot.
2. If you are not confident then tell the svc to tune the carb. (most of the svc mechanics keep the ratio a bit lean as this increases the mileage but in turn reduces performance and is not good for the engine)
3. The air fuel ratio can be determined by looking at the spark plug as well. Take a photo of the spark plug and post it here.

Re: Suzuki Gixxer 155

[MENTION=41442]Abishek94.. Thank you so much For your input.. Will definitely check the AFR ..
I may take the bike to SVC tomorrow will have the guy check the same.
To summarize,
The lag may be a characteristic behavior of the bike
Or
It could be improper carb setting
I will try to take the bike which they have for test ride once again and compare the throttle response.
With that I can isolate which on is the reason behind the lag..
At times, I am in doubt whether I am actually experiencing this problem or am I feeling like this since I downgraded..
Time will answer these questions..
Like always the xbhp does clear the air for a confused rider
Thanks once again everyone for your responses..
Will update about the results tomorrow.. Hopefully they open the SVC that is..

Re: Suzuki Gixxer 155

This is from the user's manual of the bike:
"The carburetor is factory set for the best carburetion. Do not attempt to alter its settings". I hope a direction like this is there in every bike's manual. If the bike used at high altitudes, replacing the jets is recommended; not turning the AFR screw. If the air fuel ratio altering experts dominating here are correct, the engineers designing the engine are fools. Otherwise the 'tuning experts' here are moronic. I am not sure which one is idiotic but like to believe that the latter is.
However, some expert tuners are riding with a small screw driver and a diary in their pocket to 'tune the carburetor' in every 100 meters of ride and note the number of turns in the diary to refer later. I have seen some of them on the straight roads in Bangalore recently. When asked I was told that they are trying to find out the sweet spot of the carburetor for the last one year or so. Hope they will continue it until they sell the bike and buy another carbureted one and continue this tuning.
One of my previous posts about the so called carburetor tuning was deleted by the moderator for correcting the number of turns of the AFR screw to 1.800921 where mere 1.8 was suggested by a friend. I was trying to help my rider friends but that post was deleted.
So a request to bike owners. Never try to alter yourself or ask to or allow the mechanics to alter that AFR adjusting screw on the carburetor. It is to correct the emission gases and that too with the help of gas analyzer and accurate digital tachometer. Turning that screw does not increase FE, torque or power of the bike.
And to the tuning experts. Kindly stop spreading the insane idea of the AFR adjusting in the pretense of carburetor tuning. None of the bike manufacturers are recommending it even in their workshop manuals.

Re: Suzuki Gixxer 155

I have a bike, a carbureted GS 150R I bought on 27/1/2010 which has covered about 41,000 kms, using for my rides including long trips up to 350 kms. Never tried that moronic "carburetor tuning" and so it still gives about 60 kml.
It was not even serviced at the SC after the first servicing. I am not willing to "tune" its carburetor as per advised by the experts until it is scientifically proved that that tuning improves the FE, torque or bhp of the bike.
It is true that everybody has the right to do whatever he likes on his bike but that doesn't mean that he has the right to mislead others.
Kindly try to understand what carburetor tuning is and how to increase the power including torque and hence the pickup or FE of a bike.

Re: Suzuki Gixxer 155


The point you made about the emission gases is true. Agreed. You also go on to say that turning the screw does not affect FE? It is not rocket science that a rich mixture will give poor mileage and a lean mixture will give better mileage, maybe we can have a meeting and i will prove it to you. and you also say that turning the screw does not affect torque or power of the bike. While the maximum power and torque an engine CAN produce will remain constant throughout its life, the tuning does play a role in the power/torque output. For reference i have posted a graph which was posted on xbhp itself on anothr thread. The shaded region of the graph shows the power varying with respect to the air fuel ratio on the x-axis. It is clear that power is maximum at a particular A/F ratio of around 14-14.2. If you still do not trust me or the graph, you can actually go and try it out on a carb'd bike, first lean the A/f ratio and go for a ride, then make the A/f excessively rich and go for a ride. I am waiting for the observations from your side.
Now coming to the 'expert tuners with a screw driver' part, it really takes only a few kms to tune a carb if you know the basics. So I really dont know whom you happened to meet who has dedicated his life to tuning nor do i care about the same.
Yes, none of the manufacturers recommend a change in Afr setting unless there is a related problem and my previous post about the afr tuning was to an individual who is facing a problem which is most probably related to incorrect A/f ratio.
I have only given what i think is the solution going by my own past experience, implementing it or not is up to the individual concerned.

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For the record, yes it is scientifically proven that the right Afr setting gives maximum power and torque, the limit to the same being the engine's max output capacity. It also gives an optimum mix of FE and performance. Why do you think Electronic Control Units (ECU) and fuel injection systems are being used in automobiles these days? The ecu always tries to maintain the correct afr at all rpms and since it works on electronics, it is much more effective and reliable than the mechanically operated carbs.
There is absolutely nothing misleading in my posts.
Kindly try to understand that you dont go and tune a bike which is not facing any related problems. If your GS 150R has not faced any tuning related issues in 4-5 years, then I am happy for you but that does not mean that all bikes are perfect from the showroom like your bike.