Project Dhoom YD 70 Upgrade to 110cc

[asjdsm]

hi
as the title suggests.. i have undertaken this small project.. so far i have made my bike partially ready.. here is what i have done so far..

    1:installed a 4 wheeler Cylinder of 107cc capacity
    2: and a corresponding  Cylinder head..

both the things were just bolt on fit.. no new timing chain was needed..
i also upgraded to an after market china carburettor that comes for qingqi 100cc rickshaw.. did nothing to the jets ..mixture is a bit rich but proper setting is needed.current jets are unlabelled. however from spark plug reading mixture is in acceptable range...

So far results are quite decent...pick is increased . very much..it reaches speeds of 80 in fairly short time..top speed is 90 but it severely vibrates past or close to speeds at 80. current sprockets are 14/41 default..

UPDATE [17/06/2012]
after i added the clutch box and sprocket was changed to 15/41 top speed is 100 and no vibrations..

the new 110cc head is exactly the same as of the chonda 70 only difference is the size of combustion chamber which is slightly enlarged for the 52.4mm cylinder as opposed to the 48mm chamber of chonda 70.. The intake valve is 23mm and the exhaust valve is 20 mm.same values as of default cylinder head of dhoom 70. silencer is the same old of dhoom 70..

Now i need suggestions/verifications as to what should i do to make it a bit faster.. in-fact not faster but to make the gears longer as at speeds above 60 (definitely in 4th gear) it seems as if it needs to be shifted to next gear..

Now, one mechanic suggested me to use the following
1: qinqgi clutch gear..and he said it costs 800-900 rs in new.. DONE
2: and also to upgrade to 3 discs/plates clutch boxa...( infer for yourself
what he meant.) DONE
3:someone also suggested me to open the ports ( portain khuli kara lain) [To be done]
4: replace the paper type filter element with a foam type ,, [To be done]
will make a video about the project on what i have done so far.. in a couple of days. and rearrange this thread..

also suggest a good mechanic..in pindi islamabad..

thanks..

Some pics of the new cylinder head (110cc)
This is the combustion chamber of 110cc cylinder..

Following pic show the scale next to the centre line of a 110cc combustion chamber ..my readings using vernier scale were as follows.
the inner circle is of 40mm dia same as in dhoom 70 chamber
the outer is of 52mm dia , 4mm bigger then the chamber of dhoom 70
depth is same for both..at the center line..

vernier calliper showing the outer dia.

110cc cylinder installed.. along with a piston. the piston was partially seized but the mechanic who installed it said it is ok.. many mechanics also said so.. however rings were new. of STR.. the rings which i bought were for 150 rs and they were of zero number from united 100cc bike..(that bike in reality is a 110cc)

Piston at BDC of the cylinder.

another view of piston at BDC .

Piston at TDC. not the piston was flat shaped but there was too much compression.. so we tapper cut the piston.. that's why the piston looks pretty old at centre and clean at the edge... this pic was take after this piston did some 20 Km ...

Another View of Piston at TDC,

Picture of Exhaust port from cylinder head.. no silencer installed yet..

another view of the exhaust port of the cylinder , silence isn't installed yet..

[hidalgo]

now thats what i call modification
an engine swap
good luck bro ahsan
as much i kbnow about chondas etc they are altration friendly means there gear box clutch box can be altered pretty easier as compared to others
so bro best of luck and keep us updated

[asjdsm]

after tappet adjjustments the vibration thingy is ok,, now i cheked it and the max i got was 95km/hr and still there was some reving left,,

i need some guidence about the points that i have raised and also ,, any other tip that any one has do share it,,

[Automotorsport_Lover]

I guess ur bike is vibrating due to over powered head and lower speed designed gear box.
What i can guess is happening with ur bike is the same which happens to a cycle when u paddle it tooo fast! Paddles sorta become free!

So such high reving can damage ur engine! U need to lower the Revs! By adding load to the engine! In worst cases ur engine head can blow off! (Now ur bike is not tht much powered to do this, but im just telling u)

What u probably need is to alter the engine weights of ur bike. to add some load.

[asjdsm]

^^ dear after tappet adjustment vibration is gone... its very smooth at 80-90 km/hr even.. it revs much much better.. however there is a gasket between the exhaust port and the silencer jo iss particual which is not perfect.. due to which there is some karrrr karr but that is minor issue.. just a gasket replacement will do tat and update the thread..

[overspeed111]

very nice upgradation also share its mileage..can i ask a Q? dont u get tired of everyday hassle?

[asjdsm]

very nice upgradation also share its mileage..can i ask a Q? dont u get tired of everyday hassle?

i will check exact mileage using a 100ml method to remove any ambiguity,, and will share it,, may be tomorrow or the next day,, but m using it for quitesome time ,, and it seems that its avg is not different from what it used to be, but will test it,,,

yar local so called ustaads and mechanics sa bahoth tang hotha houn as they know nothing an then they talk as if moding is a sin,, anyhow as soon as i get away from them i m ok and energized,, i like it ,, i like doing mods

and ma ciggerate nahi peetha is lia nahi thaktha

[asjdsm]

^^ dear after tappet adjustment vibration is gone... its very smooth at 80-90 km/hr even.. it revs much much better.. however there is a gasket between the exhaust port and the silencer jo iss particual which is not perfect.. due to which there is some karrrr karr but that is minor issue.. just a gasket replacement will do tat and update the thread..

silencer gasket replaced seems much better now,,

[cursedd]

Very nicely explained..keep it coming(Y)
One thing i didn't understand is that u said air filter is of paper type (that i know) and foam type(didn't get it?) u meant to say kay foam type wala wo hai jo junaid bhai ne apni 125 main use kia tha or some else?
and my advice is that i feel if u change the sprockets u will get more speed!

[asjdsm]

foam type filter is used in honda cg 125,,
read at this forum for more details,, it is what i want to do,,
Yamaha Gladiator RS Air filter Change from Paper type to Foam type - xBhp.com : The Global Indian Biking Community

or u can google for foam type filter for motorcycle

[N0m1]

Cursedd is right.U Can get more speed with Sprockets.Like Front 15th & Rear 35th.Then u Will fly:D.LolX! Or at least u can use front 16th sprocket,easily available.It will smooth ur drive and pick will also increase.

[asjdsm]

just asmall update,, today i changed the engine oil,, put 700ml havoline,,drained the old,, the used engine oil was of normal colour , thickness and smell as i would get with earlier oil changes,,the old engine oil did me 1000km approx,,

[cursedd]

thanks.. now i undesrstood:)

[asjdsm]

today i did 100km/hr... on this bike.. it was scary but had to try this and it achieved that pretty quickly and it seemed that if i need to shift to next gear but no 5th gear..
i also used the autolite spark plug which i bough from tabi hawk for 70cc.. i tried both ngk c7hsa and this autolite.. to me there was no difference in both .. but ngk was slightly better ... and regarding the issue of the core being of copper after a little research i found that all the standard plugs use copper cores..
here is an ngk c7hsa plug specs
NGK C7HSA Spark Plug

also please tell me about the questions that i have raised .. to further optimize it..

[N0m1]

100km\h!
Impressive.

[asjdsm]

pick was awesome even at 100 i felt to shift to next gear,, unfortunatey no next gear,, its ride in 4th gear is awesome and the first three gears are extremly short,

[r1]

Lalay do post some video of your altered bike!

[asjdsm]

yar i will ,, though i have crappy mobile. but will try to get its video..

what shoud be in the video ?

[daniyalahmad]

^ Your speedometer OFC.

[daniyalahmad]

Let someone else make the video for you.
Dont try to make any video while driving.
Do it on an empty road with proper safety equipment. (Atleast with a helmet)
Will be waiting for the video.