Re: Yamaha FZ - X Video Test & responses 25th July, 2013

Sir you meant the rubber diaphragm? i guess that is a possibility too.. The carb valve slide, if gone bust will set you back by INR 1500 bucks! I was surprised to find that in the Mikuni BS 26 series Carburettor:

* TPS sensor comes for INR 4500 - 4800.
* Carburetttor is INR 4500.
* The valve slide is 1500.
* The Rubber diaphragm is 500-600 bucks, don't remember the cost, mine is still OEM stock and there were no visible damages on it.


Cheers,

Re: Yamaha FZ - X Video Test & responses 25th July, 2013

this was the condition of the spark plug.. there ware carbon deposits on the ring, but the center was mostly clean.. is it lean or rich.. i couldn't make it out..
the filament looked fine..



will get the carb checked for any damage or defect in a few days..
thanks

Re: Yamaha FZ - X Video Test & responses 25th July, 2013

Hi @nadz11.ns, It appears to be a lean mixture. There should be a dark tan to brown (but not black) on the tip on plug.
However if the engine does not heat up quickly and if you do not feel loss of power after engine heating up there is nothing to worry about.

And in regards to the bike gasping at higher rpms when you downshift, I would like to add up to what others have mentioned.
* I suggest you to check for any air leak (around carb boots and exhaust manifold).
* Next time when you are on higher speeds, just race the throttle mildly by holding the clutch for it 1-2 times and downshift. See if that helps.

Personally I feel that the bike at that RPM, when you downshift, would experience 'engine breaking' and 'acceleration' at the same time. The transition takes a while and hence the loss of power for 2-3 seconds. So to me what you experienced sounds normal.

Re: Yamaha FZ - X Video Test & responses 25th July, 2013

well.. i do feel power loss at times..
will look into the carb and the things what you and other rides have mentioned..
FZ is like a beast in its category and this power loss kinda makes that feel lose its shine.. we can't expect much more on a stock setup.. but we can keep it at it best..

Re: Yamaha FZ - X Video Test & responses 25th July, 2013

***The Basics of Reading a Spark Plug*** - Honda-Tech . Try and get a reading from this. Also, can't make out from the centre picture whether there're any deposits on the plug. If so, they're potentially dangerous to the engine's health.




Edit : The image is larger on my PC, not sure why it's resized so much here.

Re: Yamaha FZ - X Video Test & responses 25th July, 2013

there weren't any deposits on tip.. but there were on on the ring part.. it was coated black in powder.. but the tip was clean..

Re: Yamaha FZ - X Video Test & responses 25th July, 2013

No issues with the ring, unless there are OIL deposits, in which case there's a leak.
Appears you're running a bit lean. As others pointed out, you might want to have the carb cleaned (properly) and ensure the jets aren't clogged as well. Tune after that, and you should have a smooth ride.

Re: Yamaha FZ - X Video Test & responses 25th July, 2013

ya, will do just that in a few days..
thanks for your help

Re: Yamaha FZ - X Video Test & responses 25th July, 2013

Glad to see so many people participating.. Productive discussions are always a welcome on this thread

Reverting back to stock exhaust tomorrow along with some jetting experiments as mentioned earlier. If the weather permits, i shall take video of the Yoshimura exhaust, while the bike is stationary: one with the DB killler on and one W/O the DB killer just to give you guys an idea how she sounds..


Cheers,

Yoshimura Full Exhaust for yamaha FZ 29th July, 2013

Hi All,

A quick video of the Yoshimura Full Exhaust system before i bid aideu to it :



More reports coming soon. In the mean time, enjoy the noise!!

Cheers,

Re: Yoshimura Full Exhaust for yamaha FZ 29th July, 2013

Came across the controvesy about the Semi-Forged piston
Here is what i got to know for the Intrnet


WHAT IS A SEMI-FORGED PISTON?

Many works bike pistons are semi-forged (also known as squeeze-forged, hotpforged or pressure-forged). Semi-forging is a process that casts the molten aluminum in a pressurized environment. Combining some aspects of casting with the high pressure of forging produces a piston that can have the weight, silicone content and controlled piston swell of a cast piston with the strength of a forged part. Some OEM four-stroke pistons are semi-forged. Another plus of a semi-forged piston is that it requires less machining than a forged piston.

More info about Piston avaliable at THE TORTURED LIFE OF THE PISTON IN YOUR TRUSTY BUT RUSTY BIKE | News | mobile

Compression tests Stock Exhaust And Rejetting yamaha FZ 29th July, 2013

Hi All,

So finally with a heavy heart, i handed over the Yoshimura full exhaust and began the next set of experiments with my bike (What can i say i am mad!! ). We first dismantled the Yoshimura exhaust system from my bike. I noticed that the pipe from the exhaust manifold till some distance, the colour of the pipe had changed over a period of usage.



Pic: Pipe from the exhaust manifold colour changed.

The colour of the pipe was similar to what is normally seen on the KTM Duke 200's exhaust pipes. My guess it is natural for the SS grade exhaust to change colour due the high temperature exhaust gases hitting the manifold and the bend pipe from there at high speeds. The same change of colour was also seen on the Leo Vince Full Exhaust system as well.We then installed my stock exhaust and decided to work on the compression testing for the same. Now here comes the weird part, as per my earlier calculations the stock block's compression unit at sea level is 1200 Kilo Pascals which translates to roughly 174.045 psi.



Pic 2: Compression Testing gauge

So when we started the test: the spark plug was removed and the compression testing gauge was installed in its place. As a normal procedure, the throttle was kept at WOT and we pressed the starter motor to build up the PSIs into the cylinder. The reading kept on stopping at 98-99 psi no matter how many times we repeated the test. I was initially scratching my head over it as to why such a low pressure reading would crop up? Unless the piston rings have gone bust or there is a compression loss through other medium, there is no way a high compression set up will show such low readings, even lower than stock.



Pic 3: Compression testing gauge showing readings of 98-99 psi.

So when in doubt: i bothered two gentlemen who are always there to help me when troubleshooting anomalies: PSR Ji and abhimanyu31. According to them the prime suspect was the compression testing gauge itself: i.e. faulty readings. As always many thanks to both of you . So i guess it is time to visit my trusted workshop, Kamla Yamaha, Sewree and annoy the hell out of them!! . Abhimanyu31 has suggested me to check out the compression testing of a stock FZ so that we are sure whether the readings were correct or there is something wrong with the data on the workshop manual. regardless If the readings show the same values on their gauge as well, i.e lesser than a stock bike then most likely there is a compression leak somewhere, either from the piston rings or else one of the valve seats might be faulty or leaking. I shall report back when i do go for round two on the same. If that is the case then i will definitely scrap the BB kit, revert to stock set up for a while and till Motozone gets hold of the NiKaSil bores and their head as well. I have no intention to spend any more time, money or effort with this unreliable, moody BB kit then.

If so would it mean an unhappy ending of this thread and a closure of the same? would i stop writing or updating any more on this thread? NOPE! It would be an official closure of my experience with the RC kits and i shall start my full fledged experiments the Motozone products and kits. But till the time we do conclude after my second compression test, let's hold on to that thought shall we?

Moving on, we then started working on the BS 29 mm CV carburettor. The main jet was kept at 122.5, pilot jet 17.5 and needle jet was initially replaced with a genuine Mikuni series adjustable but comparatively thinner one, in order to see if we can increase the fuel flow with it. The centre thing which we had changed was reverted back to stock (sorry forgot to ask the real term for the same..), and then we installed the carburettor back. We then started the bike and then began with the tests. The bike was coughing and spitting and no matter whichever settings we tried it was not working. There was a huge flat spot from 7,000 rpm onwards. Since, i had my old damaged RTR 29mm CV carburettor (now you can call it a paper weight!) for which RC never refunded the amount nor offered any other help, was lying around i decided to experiment fitting the adjustable needle of the same on my Bajaj Pulsar Carb. The theory behind this crazy experiment was that both the carbs are manufactured from UCAL and more or less identical in every aspect. The needle visually looked the same though i am sure the fuelling properties are far more different than the stock non- adjustable needle of the Bajaj 29 carburettor. We tried different settings and finally put it on the richest setting. Now the bike would rev happily all the way to the red line and short plug chop tests revealed a golden brown tan on the spark plug indicating a stoich AFR. So for now, i decided to conclude our fiddling with the set up and see what results we we get from the same.

I also met another fellow rider from xbhp FZERIDER, who was waiting patiently, checking out all the crazy stuff i make my bike go through . He was kind enough to let me test out his Repsol CBR 250R which was for me, the second time i had got my hands on a CBR since, its launch in India. Personally, the initial experience of a CBR: felt front heavy and steering was definitely heavy, not as nimble as my FZ but nonetheless the power was pretty evident on a 25bhp bike compared to mine. Thanks again for the test ride mate.

So anyways, here are my initial reports:

* The FZ - X starts at one go without any throttle input. No reverse cranking or anything
* The performance has dropped significantly though when compared to the earlier set up.
* The engine feels vibey, there is knocking between 4k - 5k rpms when attempting WOT
* The bike now takes a lot of time to gather speed and the nos. on the speedometer takes ages to climb as compared to Yoshi and Leo Vince.
* The stock exhaust feels very restrictive.
* The engine revs all the way to the redline and beyond without any hiccups or flat spots.

Mind you these are just initial observations. I am not sure whether it is a phenomenon because of exhaust or something to do with the jetting experiment that i have done with the carburettor which is leading to this. I will also try out the ignition maps 4 and 6 from the programmed CDI again and see if there is any change in performance of my FZ -X. FE test will also reveal how much i have gained and lost.


Till then stay tuned


Thanks for the inputs mate.

A lot has been discussed on the thread started by Mik and Luke: : Probably having a look there will give you a better insight on the same: http://www.xbhp.com/talkies/general-...tech-talk.html


Cheers,

Re: The POWERHOUSE Fz18

^^^ just had a thought; did you replace the head gasket when you re- torqued the head?


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Re: The POWERHOUSE Fz18

I don't think we had replaced the head gasket. What do you have in mind?? BTW folks FZERIDER had a go on my bike and had pointed out that something was not right with my bike's front handling. Today i had let one of my friend's do a test ride and he too suspects that either the handlebar locking nut is loose or else the coneset might have gone bust. Dut to the rains so far, i had not ridden her much but after their comments, i intentionally took her through a few potholes and yes it feels like something is not right. I guess being 30k old she is now becoming more demanding then ever..


Anyways, awaiting for more inputs from other riders regarding the same.

Cheers,

Re: The POWERHOUSE Fz18

I was thinking in terms of the gasket being compressed due to excessive torque application. After which you loosened the head and used the correct torque specs. However, since the gasket has already been compressed due to excessive torque specs, applying the correct torque is not creating enough pressure on the gasket to create a effective seal, hence compression loss is a possibility.


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