Topic Re-opened for now. Please maintain sanity. And no more personal rants please.

It is quite possible that someone gets misdirections/ mis informations from his mechanics.
If that happens, its the role of senior members to politely point out the mistakes and help the newcomer.


@ Biplab: I think you've shared what you wanted to share. You'll have to get more knowledge, and stop trusting mechanics for everything. You can go to my profile and message me, if you want to talk anything personally, or want your doubts to be cleared.


@ ROCKRZ: I couldn't get the numbers you used in your post. But, Joel's Bigbore replaces the sleeve as far as I know. That could mean more heat dissipation. Again, this is something I can't confirm.

Ok, let me see if I can answer these in a logical manner:

The reason for such a massive increase in power is a combination of factors and not just simple displacement bump.

1. For the 172cc big bore, Joel offers a completely new head with revised flow to handle the additional flow demanded by the increased capacity. It has enlarged valves. Compared to stock inlet 19mm & exhaust 17mm, the new valves are inlet 22mm & exhaust 19mm.
2. There is a decent increase in compression from stock 160 psi to 180 psi.
3. The substantial increase in flow is matched with specifically designed free flow exhaust.
4. Last but not the least is the increase cubic capacity of 22cc.

The reason that the engine seized is most probably due to incorrect assembly. The assembly is extremely tight on tolerances, if one is not careful in properly inserting the piston in the cylinder the piston rings can warp very very easily.

Just saw this thread now.

Firstly, the owner of this bike/thread has been really confusing with his posts and nothing has been clear so far. The thread really did not serve any purpose, but added confusion and unwanted discussions. Starting a thread for the sake of it or for the purpose of it, is something the owner has to decide on his own.
I'll clear the air myself.

FIrst off, there was no promise of 25hp with this package. Unless stated by ME, pls do not conclude. The 25hp figure is with a hotter package than this.
Yes, we have achieved it and run on streets. The race bike makes a lot more than that. And we still run the std radiator.

Now getting to the point of what can go wrong.
A lot can go wrong during install, esp with an LC engines.
Airblock in the coolant system with does not allow the coolant to circulate and causes overheating. Caused due to improper filling. At one point, the airblock could pass out, but by then the damage is already done.
Damaged head gasket - The R15 dowel pins (at the time of install of the head, over the block, if you aint careful) is known to scratch the surface of the head gasket, which causes scars and leads to a small leak. The coolant seeps into the liner and later results in a water lock-up in the engine - seizure!
Not replacing the head gasket also causes the above situation
Wrong piston installation. I wonder how even yamaha mechs cannot understand which is the thrust side of the piston. Causes excess slap on one side of the wall and causes friction.
Not installing the piston pin locks - seen this a few times with most mechs goofing up on this.
Not coating oil on the surface, pistons and rings while installing, which leads to friction and could take a toll, at a later stage.
Improper run-in - carrying pillion and stressing the engine, wrong oil grade (using super thin snyth oil), revving engine is neutral soon after install, taking-off even before the engine has warmed up etc.
The reasons are endless.
We have hundreds of blocks which are running and clocking kms without a hitch.
Tuning is right, when done right. A wrong install cannot get away. It will show up, sooner or later and it will be bad.
Its a pity that most mechs do not have an understanding of putting back these LC engines.
The last time, someone said he will have his CBR head removed by a local mech to send down to me for a headwork, I declined. I do not wish to take up blame, if the mech did not install it right or goofed up something.

I'm going to be making an educational video on installing these blocks, setting cam timing and other critical installation instrcutions soon. Should clear all these confusions.

Its a sad state right now. The owner takes the part to the mech. Goofs up the install, part goes wrong and then blames it. The blame game is easy.

Thanks, but I'd prefer a technical one.

I'm noob on 4S, so pardon my ignorance there. But the rebore, AM exhausts & filters are nothing new in the world of 2S which is almost similar here. So, with a great effort (like stage 3 porting, expansion chambers etc) its possible to bump up from 11.8 to 16bhp on a 2S 135cc engine & this is a massive modification for such a small engine & mostly these engine builds last for not more than 10-15K km. Anyway, that's immaterial here.

I understand with point 1 & 3, there's a considerable increase in airflow from stock & point 2 the CR is increased from stock 10.4:1 to not sure how much. And point 4 is reboring the cylinder size from 149.8 stock to 170cc. I'm sure with the valves being enlarged the timings would also differ & sure there's a camshaft replacement & also the ECM.

So what leaves me a little puzzled is that the new timing, additional 20cc & increased CR, is this all that is required to get additional 8.24 bhp BTW, was the vehicle dyno'd before & after the modification to show the figures of 16.76bhp to 25bhp? I seriously feel ashamed to have bought the CBR if R15 can do this; really I mean.

Edit -
Excellent

Edit -
This sounds promising; awesome would be when we hear something positive from you on CBR 250R goodies (though OT, I hope the moderators don't delete this)

I think this is long overdue ,to Insure what is intended is done,and ensure proper install......make it an Elaborate Video covering all of the aspects of the install since most Mechs will need it..
Would request you to do it ASAP and then ship the mods..just so you don't end up playing ping pong with parts replacement and free up time to actually do other development work.
Just my Thought

I Never Blamed U..And i Also Said U Replaced The Block piston And Now Every thing Is Running Well And U Did Said After the Head work I Will Be getting Power of About 25Bhp.....Anyways leave that But i Never blamed u...

Thats What I Said It Was All my Fault that I Got My block Installed From A Local Mechanic To Save Some Time And They Didnt Installed It Properly And After That Mr joel Replaced The Block Piston And i Got it installed From An Authorized Yamaha Service Center And Now i Am Not Facing Any probs.So What I Want To Say Through This Experience Is PLS LISTEN TO WHAT MR JOEL SAYS AND ALWAYS GET IT INSTALLED FROM A AUTHORIZED YAMAHA SERVICE CENTER

Buddy, really sorry that a hornets nest has been stirred here. Sincere appologies.

As PSR rightly said, MAnufacturers put restrictions due to reasons which are beyond the scope of this topic. Modifying something will always have side effects. heck, why blame Joel or the the mech who installed? I had once opened upth head cover to replace the rubber gasket and i ended up getting the whole block piston assly just because i dropped a screwdriver bit into the engine. even i am learning the engine in detail as i face problems with my bike. you see, getting into mods is very easy but getting them to work properly and reliably is a whole-together different story.

My warm regards for your new modded R15.
As from some movie (which i have forgotten, MAY YOU ACHIEVE GREATNESS :P

OT PS: If you can source me an Zmr engine, please let me know :P

Yes I Can help U

Thanks buddy and today i completed my runing in and did 152km/hr with my stock ECU....

Ok Mr: Biplab,

I remember guiding you throughout your way on these modifications, but the talks we had are quite different from your posts here. Anyways best of luck.

I think its time for a proper review on a proper R15 Bore Upgrade here, will do it today.

What I have not understood is why individual people are opening the same thread again and again when their bikes get joel'ed?

There already is a thread which discusses Joel'ed R15s. Just add to that thread! Or maybe the mods should move the thread properly.

Even I have gotten my dazzler Joel'ed doesn't mean I should start my own thread because a thread discussing Joel'ed dazzler already exists man!

Everyone's got a different and elaborate story.Mixing it up all together would be chaotic.

Isnt this the case with every bike? everyone has their own story to tell.

Lets not spoil the spirit of the person who owns the bike.
This decision of a separate thread or not rests on the moderators.

Just what I've been thinking about too; is it a coincidence that Mr.Harish also experienced initial stages - http://www.xbhp.com/talkies/pit-stop...ing-tuned.html. He had also gone for replacement.

Yes, apologize to Biplab