@nanotech

Dude you can go for 180 bore kit with your eyes closed.Regarding head, there's no need to change it.You can get the combustion chamber size increased in order to accommodate the bigger bore.Bigger carb and ignition of rtr are optional.But jetting is a must!
My advise ? GO FOR IT!!!!

@bprags
Man tell me something about the previous big bore set up you were using .As to what was the bore size,the kms it lasted, where you got the lathe work done etc.
Coming to your current set up ,how much did the rtr idi ,bore kit cost etc.How's the performance of the RTR idi unit?
I have a 195cc config and the engine is silk smooth .In fact its smoother than stock.Any ideas as to why the NVH of your bike has gone up? Which crank are you using?any air filter mods? or a free flow exhaust?

PS: Brand new carb ucal BS29 AND BS32 COST 2100 bucks at the Bajaj showroom and at the ucal distributor also. Personally i am going for a used 29 mm carb or a back door carb from bajaj dealer .

@nanotechnology
I'll be going to the tvs dealer to buy a spark plug today,when i'm there i'll ask the cost of the bore kit .

thanks buddy.
if i can keep my own head now, its well and good.
I'll get jetting done presently, but change the carb to BS29 or BS32 later on..

if i can fit up everything within 4.5k then I'll do it by next week itself, if not then maybe some other time or maybe NOT.

and please can you please explain in detail the expansion of combustion chambers??
all i got into my head so far was just fit the bore kit in replacement of this kit...
of-corse the piston too with rings..
and i suppose that the current piston connecting rod will work.

jetting can be done by a carb specialist, or maybe i can myself replace those small jets to bigger ones.
but i am sure i'll end up wasting 4-5 spark plugs to determine weather its done right.

anything else???

Yeah man it won't cost much.But not the same performance you can expect when joe's worked on it
You can opt for the bore kit and get the head's combustion area extended to match the bore size .Then jetting is cheap affair and you're done !!
Coming to the combustion chamber expansion .What they do is grind out the head's combustion area to widen it to cover the increased bore size.Here compression can be increased based on whether the area around the valves are grinded or not.
The connecting rod doesn't need to be replaced .Provided it's ok.
That means the total cost will be the cost of the 180 bore kit plus the lathe work to expand the combustion area and the porting is optional but advised.That's it!!!!!!!!!!!!!!!

PS: Crankshafts need not be replaced if they aren't damaged .All it needs is to be re-set at the lathe.They replace the bearings and re-set it.My bike's crankshaft was fine and so is yours as you are not facing any probs.

@nanotechnology

The things that need to be done:-

1. Buy 180 bore kit(comes with piston and rings)

2.Get the lathe work for the combustion chamber area increased of the head part.That is from the stock bore width to that of the new bore which is 62.5 mm .Here ask the compression to be kept relatively low.That is ask them to grind out the area surrounding the valves to increase the size of the combustion chamber.

3. Porting of the head (optional but highly advised)

4. Mech will check the crankshaft for any play.If its there then crankshaft needs to be re-set at lathe.If there's no play and bearing is fine ,then nothing needs to be done to it.

5.Jetting/carb tuning

thanks gixxer..
i understand that porting is the process, in which the air intake of the valve is modified with a new inlet.. am i right?

my CAM-shaft is just 4300 kms old, so its new and does not need replacing..
besides, do these lathe guys know what they are doing?
how much did you guys pay for the lathe work?

62.5mm, copy that.
from 57mm ,its decent.

and gixxer, did you ask the cost of the A180's block?

PORTING IS OPTIONAL too buddy

Lathe work is simple and minimal .Just take the bore ,the RTR 180 bore and tell them to match the head to the size of the bore.Thats it.
I wasn't ab;e to go to the dealer because of rains so called up Rajesh the guy who's worked on my bike and bprags .He told me the RTR180 bore costs around 2500.Apart from the bore kit and the small lathe work which might take not more than an hour at most ,rest is just fitting the engine.
You can go for porting at a later time too.Just get the bore installed and do jetting and you will have a 180cc bike.

thanks buddy...

i will do it.
i am feeling very tempted.
but running a bit low on cash, i might take some time..

if i ask then to keep compression as low as possible, they won't design the head like a curved slice right?
all they will do is just widen it a bit from 57 to 62.5, that's it..

will it provide any problems to the tappets?

secondly, as bprags and you are already running such setup, do you have an idea about the jet sizes which will match perfectly?
it will save my trial and error method.

1 more thing.
if i update my carb later on, which one should i go for BS29 or BS32 ??
let me know the difference, as i don't have much information about the carbs...

Porting has to be done right ,otherwise it will cause valve problems like increase in noise etc.As when porting the tracts(inlet and exhaust)they will remove metal from the head.
If you are not sure about the lathe guys ,then don't go for porting for the present time anyway.
If you wannna be on the safer side ,then don't tell them to reduce compression by grinding out the head's area around the valves.That is keep it as it is.
So all that is left to do will be to match the size of the head's combustion area to that of the bore,which is to increase it from the present 57mm to 62.5mm.Which is 15 mins to an hour's work at lathe.The charges wont be more than 100 to 200 bucks for the lathe work maybe even less.
Just buy a pulsar main jet of the size 110 and 115 each costing 15 to 17 bucks .
Buy a NGK R CR7E spark plug, which costs 75 bucks.
Then the packing and head gaskets.That's it.
No need to do anything to tappet other than adjusting it.

Forget about bigger carbs for the moment.I will be buying one shortly and i'll let you know about it.
If you go for porting ,then you can buy ucal BS29 carb.As joel joe used it on his highly tuned fiero 195 and was more than enough for him to set the highest speed.Then bprags is also currently running it with good results.

The more concave the combustion chamber area of the head the less compression and lesser the power.
So ,if you aren't confident about the lathe guys skill and as suggested in my previous post, not to ask them to grind out the area around the valve in the combustion area of the head,in order to reduce compression.What will happen is since the combustion area will be widened only to match the bore ,resulting in relatively higher compression.
All these things have nothing to do with the tappets.

thanks man..
so only jetting will be done now.

about porting, I'll see if i feel confident I'll get it done, besides everything that you explained had removed all the doubts from my mind.

thank you again.

last question,
pulsar main jet of size 115 and 117 each?
do we need 2 jets?

also why not NGK IRIDIUM ?

Get things done one at a time if you are not sure.That is first get the bike to 180cc and do jetting .Then go for porting and bigger carb when you are satisfied with the 180cc set up.
The jets are there to play around My bike's running on 115 main jet and its not enough.But the 125 jet is proving to be too rich in the current set up.
Once the spark plug is settled with then you can go for iridium ,for now normal plug is needed to tune the carb/jetting.
I have tried lot of plugs and still intend to buy the twin electrode bosch one today.But the best plug i've found out so far to keep the engine's NVH low and engine performing well is the NGK R CR7E which is the stock plug.

thanks again gixxer.
I've spoken to vishal today.
he knows the right people for each and every job, and i feel very confident now.
i think I'll straight away go for 115 main jet, as its lean for a 195, it might be enough for a 180..
if i am happy with the performance i might go for big bore on that 180 block too, to make it 200 or something
but that will happen not before a year, if the bike still lives..

1 query,
you earlier said that fiero f2 has 2 modes economy and power mode with different mapping, which means i will get better output with the power mode, i.e low revv limitations?

as i don't actually plan to go for apache rtr's CDI unit.

besides i need to change my sprocket set too, its kinda needing replacement, so do you guys suggest some particular, bigger teeth setup to match that 180cc performance??

@ chief ashman.

bro, your run-in period might be over by now !!! isn't it?

how's the bike running?
keep updates on bro..

@ chief ashman.

bro, your run-in period might be over by now !!! isn't it?

how's the bike running?
keep updates on bro..[/QUOTE]

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Nano bro... I have been a silent follower of the thread for some time... The conversations are into upgrading the aging Fiero ... something not on my mind at the moment ... but one never knows in the future I may join the bandwagon. Since I know nothing about these things, I have been maintaining a low profile.

It's monsoon bro and the roads are muddy so riding less ... just to work and back. The bike has been ok... it's just completed about 400 kms so far. But I find the engine is getting smoother by the day. I guess the first servicing will be a critical one... as I will have to sit with the mech and tell him exactly what I want... I think the tappets need to be tuned. I will also be replacing the chain sprockets set and the clutch plates. So I assume after the 500 - 800 km (I have a good mind to wait for about 750 km) servicing, things will be butter again. I will then have peace of mind and enjoy the Fiero.

One thing has been bothering me lately... it's the starting key lock. I have replaced the original lock with something else quiet recently ... just about 3-4 months back... and now it's giving problems again. The bike shuts off by itself in the middle of the road and I have to really twist the Key to make it start again... this often happens before the ride too. Can anyone suggest me a good reliable lock and key set for the Fiero?

Good to hear chief that your bike is running well. Keep it running .
Nothing as good as the original set of lock, though it does not come cheap Maybe there is a rusting issue in the lock due to the rains & hence the contact must be breaking off. Try to put some WD40, rustlick or some similar products which are antirust products.Else you can even put in some motor oil in it.

Vishal