Re: The POWERHOUSE Fz18

Good to know that niggling problems are getting settled...
I feel you should say good bye to your BB in the interest of the rest of the engine's life. Right now nothing had happened to the internals..imagine if the Piston suddenly shatter and drops metal pieces inside...as such I remember your post that the Piston inlet and outlet marking and hence the weight is lop sided, and it must have by now made the bore Oval in shape.....Try to open the engine and inspect for worn bore and Piston skirt... Sooner you take the BB + Piston out , safer the rest of the engine will be.

Re: The POWERHOUSE Fz18

Hi All,

sorry for not updating the thread.... Been busy and been lazy from posting my usual detailed blabbering here .

Anyways, off lately my bike was behaving quite erratic in terms of handling and the accleration went down drastically. Also when i would start to roll off on 1st gear, there would a be "Khat" noise emanating from the rear tire which would disappear subsequently once the bike is in momentum. So i was scratching my head over it and also had a long chat with @psr ji regarding the same. He suspected that the cush drive/pads might have gone bust or else it would be a good idea to get the rear wheel dismantled and inspected properly.

For readers who have no idea what a cush drive is and what are it's primary functions please go through the following links below:

Cush Drive: Cush drive - Wikipedia, the free encyclopedia

Video Link: Cush Drive Replacement - YouTube

I hope whoever might be facing the problem with their respective bikes will also get the cush pads and the rear bearings checked and replaced as in when needed after checking the video link above..

Anyways, after inspection at the SVC, it was discovered that the rear tire bearing has gone bust. Simultaneously, for some odd reason my bike was consuming rear brake light bulbs quite quickly. I have a suspicion the so called cheap aftermarket 10 bucks bulbs were the culprit so decided to give a shot with the OEM Philips 5 watt bulbs for 30 bucks. I picked up one extra as a spare so that when needed i can do my own DIY right in the garage. Got the rear tire bearing replaced along with cush pads as a precaution. My FZ - X is now accelerating vey very fast!! I have a feeling it was actually the main culprit behind the limited top end eating away a lot of power and creating a lot of friction at the back. Must have gone bust sometime back and my SVC guys might have ignored to inspect and grease it.


Regardless i am sharing you a screen grab of the bill:



As one can see Yamaha has been very kind in keeping the prices of the parts really cheap . The bearing costed me peanuts in comparison to the critical work it does with keeping the wheels turning. As a precautionary measure i also got the front tire bearings checked. It is functioning well but still i shall be getting it replaced within the next 5,000 kms as a preventive maintenance.

My FZ - X's engine oil consumption thanks to the crappy bore has gone up significantly so it has become a serious headache. In the coming week's i shall let Mr. Vikram take a call on whether we continue riding with the same bore or what would be the best course of action to be taken. Under the circumstances, all high speed runs with G-tech and Go-Pro videos have been scrapped keeping safety of the engine and self in mind.

I am aware that the report on the Go Pro run in which my FZ -X managed 130 kmph and the 'Tooner' racing clutch springs vs stock are pending. Give me some time to clear out my work schedule and then i shall share the whole lot with you all.

Until then..


Cheers,

Re: The POWERHOUSE Fz18


I mirror that, expanding the combusion chamber is not as easy as we think or being thaught. A 200CC FZ from Yamaha factory will be altoghter a different engine assembly. Even the Pulsar 150 vs 180 or Apache 160 vs 180 arent the same engines internally though they look, sound and taste identical.

Re: The POWERHOUSE Fz18

Re-boring is a common action to restore a worn cylinder block and piston....the increment in size of increased Piston and bore is 0.25mm than stock..Each re-bore will be such increments till the 4th over size..ie., 1mm more than stock.....OE pistons for such an exercise is available for most engines....where no such piston is offered by OE then aftermarket Pistons that have least temperature expansion coefficient is selected for the re-boring....A forged Piston is one such choice...
If the competence of the boring machine, and it's operator is in question, then the easy and reliable way, is to go for stock Bore and Piston assembly from the manufacturer .

----consecutive posts auto-merged-----

Yes...but the most important thing to note is the expansion coefficient of the Piston with heat, and how far the bore can be overbored safely.......
The distance between the Piston Pin to Crown, it's weight, head shape, are some of the critical parameters to be carefully selected if you want a reliable re or over boring to be done.

Re: The POWERHOUSE Fz18

So you can get piston of any dia you want???


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Re: The POWERHOUSE Fz18

If its only the rings that have worn out, you can just replace the rings and regain compression. The reason for reboring, is that if the cylinder walls are too scored then it will not be able to provide a tight seal against the rings, thus leading to lack of compression, loss in power and bad sound.

Reboring increases the bore dia, generally in increments of .25mm. Then an approprite oversize piston and ring set is put in. People often go for reboring because they believe its a cheap and easy job. In effect, if not done correctly it will blow up in your face.

Many aftermarket pistons are equal or better than the ones provided in a stock bike but are a costly affair. In a 4 stroke bike, where spares are available in the market, and are comparatively cheap, you can directly go for a cylinder swap. It will save some headache, as if the clearances in a rebored cylinder are not properly put in, it would not work as intended and end up wearing out the new set up even faster.

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Re: The POWERHOUSE Fz18

[QUOTE=siddharthsure;1006660]Btw guys i have a question.. When a bikes engine worns out say busted piston rings and white smoke, people go for reboring.. May i know why they do that?? Reboring means increase in dia of cylinder and stock piston is not a correct fit... Right?? So what piston they use?? And why not a brand new stock piston and rings instead of reboring which according to me is not atall precise and cylinder loses its original strength.

There are after market oversize pistons available.But I hear many of them are not upto the mark,also bore job needs to be perfect,So nowadays many stick with new stock bore and pistons.

Re: The POWERHOUSE Fz18

Btw guys i have a question.. When a bikes engine worns out say busted piston rings and white smoke, people go for reboring.. May i know why they do that?? Reboring means increase in dia of cylinder and stock piston is not a correct fit... Right?? So what piston they use?? And why not a brand new stock piston and rings instead of reboring which according to me is not atall precise and cylinder loses its original strength.


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Re: The POWERHOUSE Fz18


There is no harm if one wants to experiment for the pursuit of knowledge.. But more or less the results will remain the same.. either you will get a better mid range or a better top end but never a balance of both plainly because of the nature of the engine and the capacity.

Stock exhausts will always give you stronger mid range but a crappy top end.. agreed with FFEs the engine's revs open up drastically... I guess the tank range of 400+ kms is helping you to keep up running costs down eh?? :P


Cheers,

Re: The POWERHOUSE Fz18

[MENTION=32641]shv18[/MENTION], Good info on the carb there.

Let me share some info from my side. I think my carb was very much similar to the one you posted, but it was 33mm and the slide was not round but mostly in the shape of a D, more like round on one half and almost flat on the other. And my observations were similar too, a very good top end (which is also partly attributed to the free flow filter) but a moderate low and mid range. I did a few jet changes myself which had improved the mid range. But FE was pathetic , there wasnt proportionate increase in performance for the fall in FE! Might also have been due to bigger than needed main jets.

Have been on stock carb + filter for a long time now.. Sometimes I miss the extra punch at top end on highways but the extra tank range due to higher FE (40+kmpl consistently ) and the reliability of engine due to stock filter is worth much more!!

Currently I have been running on stock exhaust (FFE needs some cleaning) and the low end is even more pronounced at the cost of top end (Well, that's the way FFEs are right?).

Will try out the experiment of putting the 33mm carb with the free flow filter along with stock exhaust just to see if the low/mid range is better than before. This is just for my own observation and learning. Let me see what happens.

Re: The POWERHOUSE Fz18

My mistake, its 32 n 33.

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Re: The POWERHOUSE Fz18

Sir the actual carburettor when received by my friend was covered with dust and filth which i guess confirms the point of origin i.e. breaker's yard. The main issue was, he was supplied a non functional carburettor while he was charged (read overcharged!!) the full amount for the same without inspecting the unit before shipping it to the end user.

With the 32mm carburettor the performance of the top end will be great which is good for a track but then again like you have mentioned, majority of riders don't have access to the track and 70 - 80% of their commute is within the city limits which limits their riding to low end and mid range. In this case using this carburettor will prove to be a nightmare. Unless one is willing to live with this trade off for a higher top end.. stick with BS 29mm CV carburettor.


Pulsar 220 comes with BS 32 carburettor while Pulsar 200NS comes with UCD 33 carburettor as far as i am aware of. There is no 31mm carburettor from UCAL to the best of my knowledge.

information about:

* Pulsar 220: Pulsar 220 carb - BCMTouring
* Pulsar 200NS: 2012 Bajaj Pulsar 200 NS - Top Speed


Cheers,

Re: The POWERHOUSE Fz18

The 220 comes with a 30mm autochocke and ns comes with 31mm carb.

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Re: 32mm CV carb courtesy Tooner, more fun stuff, 1st November 2013

Shv18....what you have showcased here from ,...the Bigger carburetor to the reason for poor low to mid end are but recollection of painful experience of many ...even recently another member who had gone in for an " Upgrade " of 10 cc BB etc., had got the 32mm carb., to replace a 29mm for a BB Kit of JUST 10cc Increase...... needless to say only the top end was good, the FE was pathetic.....and the member was mostly using it in city...The problem here is that most of the people going for BB kits are users who are going to ride the bike in the city under low to mid RPM range, which does not warrant such big Venturi carbs....There is a lack of understanding of the principles of proper tuning of a bike by the supplier of parts......
I am Happy that at least the Carburetor supplied LOOKS new....in most cases they look pathetically old,used and full of dirt and grime.
Continue with your informative posts , which should throw more light on the ways of the " Tooner "

32mm CV carb courtesy Tooner, more fun stuff, 1st November 2013

Hi all,

thanks to another victim for shipping me his 32mm 'performance' carburettor for inspection, which he was promised by our Tooner will provide him out of this world performance. Now one correction on my part. The carburettor the Tooner seems to be currently selling is not a semi flat/D slide type but a standard round slide, Mikuni CV carburettor. Let me share some pics with you all to give you guys an idea about the carburettor:








If my hunch is right the carburettor is not brand new but has been bought off from a salvage yard/breaker's yard and is most likely from an old 400 - 600cc inline 4 motor. Now readers please don't get put off by the word second hand or stuff picked up from the breaker's yard. Worldwide it is actually a common phenomenon for tuners and speed enthusiasts to pick up good condition parts from such salvage yards in order to keep the overall costs under control for the build.

Just to keep things in the perspective check out this episode from Wheeler Dealers where they source out a re-conditioned/second hand Supercharger for a Mercedes Benz from Breaker's yard:
Wheeler Dealers S11E08 Mercedes SLK - YouTube


Anyways, coming back to the 32mm CV carb.. as per the rider, the top end is good but low end and the mid range was more or less non existent. Now one may wonder why the bike was losing steam at the bottom end when one is putting in a bigger carburettor which should translate to more fuel and air being pumped in = more power generation right?? Well the problem is with the Venturi velocity. An engine has a specific limit to what amount of fuel it can 'suck' in at different speeds. Now because one has mounted a bigger carb, the size of the venturi is bigger which actually results in reduction of vacuum pressure and speed of the air fuel mixture going towards the combustion chamber. Imagine you trying to drink your favourite soda with a smaller sized straw and then trying to consume the same drink with a garden water hosepipe. Your vacuum potential remains the same but then it is not sufficient to draw in the soda from the bottle to your mouth unless you exponentially increase the vacuum creation from your end vis a vis engine doing the same for getting in the AFR in. Not exactly a great example but hope you get the point..

With a 32mm CV carburettor on an FZ, the venturi velocity of the air and fuel mixture is just not enough at the bottom end which results in engine starving off from the required fuelling. Thus, my friend finally found out that his bike would like to idle only at 2,000 rpm and not below and in some cases for other riders: erratic idling, cold start issues or even worse the engine rpms coming down at ridiculously slow speeds even after one has shut off the throttle. The second major issue was that the mouth of the 32mm carburettor would simply not fit in into the existing contraption of the FZ... so one can expect an air leak from the carburettor making things worse. As a result, one will not get the desired result in terms of performance right from the bottom end to all the way to the top end. What most of the riders experienced was that the top end increased slightly higher but at the cost of FE and overall performance in terms of streetability.

What ticked me off was the price at which our respected Tooner was selling these 2nd hand carburettors for: RS. 6,500!! And for what?? When i got the carb inspected from Motozone what we found was the carb slide was faulty, the throttle slide would not return properly to the original position as quickly as it is supposed to. A lot of parts were missing from it and also a lot of internals were in bad shape. I guess i have uncovered enough and by now we all already know the true intentions of a profiteering start up at the cost of trust and hard earned money of unsuspecting riders don't we now??

If one is still willing to experiment with a 32mm CV carburettor, you can try your luck sourcing out stuff from Pulsar 200 NS or Pulsar 220 which if i am correct comes with 32 mm CV carburettor from UCAL and the cost according to my estimates should not be more than 3500 bucks at the max for a brand new piece from a Bajaj official spares shop. From a salvage yard, the same would not cost more than say 500 - 1000 bucks for a good condition carb. Mind you though, you will still have to get hold of the correct jets in order to get the fuelling right.. though if one has understood the explanation above, it will leave you with more headache than joy when it comes to getting the max out of your tuned FZ as you will never be able to get the low end and the top end performance at a satisfactory level.

As always, i would request senior riders to please correct me on anything i might have missed out on the explanation given above...

When i start experimenting with Flatside carbs.. i shall try and provide more write up on the same.

For the benefit of the community and to understand the terms: Head porting and Polishing, Head shaving etc. I am sharing another episode from Wheeler Dealers regarding the same on a Lotus Elise in order to extract more power:

Wheeler Dealers - Lotus Elise S2 - YouTube


A wiki link to Head Porting: http://en.wikipedia.org/wiki/Cylinder_head_porting

Hope we have learnt something more today


Thank you for your kind words.. well the effort is on..


Agreed sir. The moderator deserves an appreciation from everyone of us.

Well let's hope all of us can always add some more informative posts and in the end help each other learning something new everytime on visits this thread.


Cheers,