YX160cc into 191ccBeast Am I crazy?

[epod]

G'day all, the weather sux so nothing better to do than talk up my new build.
I have a V2 head with S25 Cam and TB decomp button, Plus a 65mm piston and barrel ordered. Should be here soon enough. I could put this kit on either my YX 150cc or YX 160cc to run in my pitster for racing and run on single tracks and mx.
I would like to here from anybody running such a big bore kit on a yx pitster setup or similar.
Is the 191 going to be out of control with the V2 on it? Should build the 150 into 181 instead.
I am told the standard clucth baskets hold up fine to the 184cc builds, will the 191 be a bit to much for the stock basket?
The american kid I am buying the V2 off says he's 184kit with V2 and S35 does 22.93hp on the dyno. Thats a lot for a 12" back wheel. He recomends gearing from 15- 39 to 16 or 17 39 combo's.
Any comments appreciated.
Ride on DD

 

[wogtaz ryder]

The Power should definately be there , if you need more the s35 is a overal rev range upgrade on the big bores.

I would probably go for a clutch upgrade.

Gearing is preference , i was running 14 front on mini tracks (I find using 3rd-4th have alot better power spread then 2nd-3rd with tighter gearing)

And on the w/e at blackduck (all massive big bike tracks) i swapped out for a 17 front and it still needed taller gearing , was all 3rd/4th pinned


Should be FUUUN let us no how it turns out .

How long till you will be riding it?

And what type carb you going for

 

[SunnyCoastRider]

do you like buying new tires?

 

[wogtaz ryder]

Good call ..

Heres mine after the weekend.... Isnt no cheap tyre either.. nor is it soft.
Another day there and would of been ripping the middle nobs off

 

[epod]

Cheers, gona run a PWK28 from akunar comes with a jet kit. But a will have to run a 26mm OKO flatslide for a while till I have some extra cash. I am going to try the stock basket first as I have 2 more stock baskets spare from lifan 140 motors with gear box issues. I run heavier springs on the 5 plate clucth but if stock plates splip i will install Kevler plates.
Paying for the head tomorrow but it is coming from UsA so not sure how long it will take barrel and piston should be here on wensday this week. have to bore the case's to fit the barrel and might even run it with the stock head to see how it goes then I will be able to judge the v2 better when it goes on.
So black duck is open again. Do your V2 add much to the 155z mate?

 

[wogtaz ryder]

Yep its back to $50 a day , bloody awesome!

Yer the head made a hell of a difference!

Got it off daimojay he ported it and put 450 springs and s35 cam in it then i just added the tb hc piston, and its a frigging rocket ship now , and with the springs you cant valve bounce the thing , it just keeeeeeps revving.

I reckon it needs a 28mm and a nice pipe and it would be a beautiful setup.

Sounds like a awesome build tho , be good to get some feedback once its done.

Try and compare the bore kit , then add the v2 , then add the carb . will be good to see what each step effects and what makes the best difference.

 

[NRG]

YES you are Crazy! But it will be fun to watch! post a Vid on first run!

That combination will have WAY too much compression and will most likely LUNCH itself within a few mintues.

The decomp cam will only reduces the compression enough so you can kick start it, but does nothing when the engine is actually running.

With a stock V2 & the 65mm in either the YX150 / YX160 (Worse) compression would around 18:1.
Stock YX150 is 9.4:1 & YX160 is 10.5:1 & To give you some idea, most race bikes are running between 12:1 - 14:1 Comp depending on the fuel used. You would not exceed 12:1 if you are running PUMP Gas!

Hope info was helpful.

 

[epod]

Funny I picked up the bore kit from daimo.
To scared to kick start it without the decomp though so if i install the stock head will have to clutch it. Would be interesting to compare though as the stock head has a home port job also. The V2 i am getting has also been ported.
Will let you know how it goes. Still have not decided whether to run it on 150 or 160 base, making 181cc or 191cc. What do u think guys, is anybody in Oz running a 191 or 192 on MX setup not monkey bike.
Ride on I off to get a feed.
DD

 

[woods11]

I have an LXR with a 184 V2, PC pipe 28mm carb. Its good on mini tracks but could do with more on the big bike tracks, maybe 220cc would do it better.

 

[epod]

Interesting thoughts on compression. I am using a decomp button the cam is S25grind. Should start easy. Plenty of crazy riders in the states are running similar setups without blowing up top ends. Clutch baskets can be a problem appartently.
I will be running 91 pump fuel. How did you calculate the compression in the cylinder during running.
Cheers DD

 

[epod]

I really gotta go eat, but woods how long have you been running that 184. Could you really use more power?
ride on DD

 

[wogtaz ryder]

Also with the S35 , the overlap or something it gives bleeds off most of the compression , after getting it past tdc i can kick with my hand .

and the Z's have more compression stock then the yx's.
Yer how do you get those comp numbers nrg??

220 woods!lol . i reckon you could get alot more power working the kit you have got

 

[Stompy_Chan]

YES you are Crazy! But it will be fun to watch! post a Vid on first run!

That combination will have WAY too much compression and will most likely LUNCH itself within a few mintues.

The decomp cam will only reduces the compression enough so you can kick start it, but does nothing when the engine is actually running.

With a stock V2 & the 65mm in either the YX150 / YX160 (Worse) compression would around 18:1.
Stock YX150 is 9.4:1 & YX160 is 10.5:1 & To give you some idea, most race bikes are running between 12:1 - 14:1 Comp depending on the fuel used. You would not exceed 12:1 if you are running PUMP Gas!

Hope info was helpful.

Helpful? .... well yeah and no .

Yes it's probably more helpful than threatining to sue the site and mods I'll give you that .

but like your unproven dyno figures your compression ratios have just confused the crew ... we all wonder how you got these figures and you don't say mmmm just like the dyno figures .... mathematically we are not that stupid so please explain how you came to these figures .

besides that crew are running this set up in the states all day which would suggest it doesn't detonate in 5 minutes which suggests said figures may be wrong .

Tell ya what .... if you REALLY want to be helpful try answering this thread

http://www.miniriders.com.au/mini-chat/21896-free-dirtmax-50sbrotherhood-4.html

And lastly a tip to you from me .... this one's free

If you are expecting people here to believe you when you say the legal threats on the site and mods here was all about protecting your name and that you welcome new companies into the market ?

Well you should maybe protect your name before trademarking other peoples ?

That way SOMEONE might believe you .... but it won't be me Bill.

Word: Dirtmax
Image:
Lodgement Date: 31-DEC-2007
Lapsing Advertised: 02-JUL-2009
Class/es: 12
Status: Lapsed/Not Protected
Kind: n/a
Type of Mark: Word

Owner/s: Bill Sayed


Relax Bill I thought about it but that would just be lowering myself to your level ... and we couldn't have that .

Still I'd hurry up and trademark your name ..... maybe not everyone here is as morally developed as me.


Now back to the thread ... sorry to hijack it there for a bit Durant ... I've seen other motors you've built and the one you did for the unlock the box section in the 50sbrotherhood is still running strong as a motard Dready tells me

So I say go for it mate if it fails it fails ...at least you'll know

 

[NRG]

TB V2 65mm YX160

TB V2 Head is 12cc with allowances made for Raised Piston and Valve Cut Outs.

YX160 is 57mm Stroke
Headgasket is 65mm Diameter with 0.1mm thickness

Compression Ratio is 16.33:1

Using the same information for a YX150 with 54mm Stroke / compression is reduced to 15.5:1

PUMP GAS no more than 12:1
Race fuel between 13:1 - 14:1 / 14:1 would be my limit

Anything above 14:1 compression will most likely result bottom end failure eg: Clutch pack gears / Broken cases.

Online compression Ratio calculator used from Engine Compression Ratio (CR) Calculator

HAVE A NICE DAY

 

[krazed0451]

One question down, several to go...

I'm really tempted to TM a certain name

 

[mattbombers]

yeah i actuly checked out them when all the v*****x fiasco was happening... who really cares, lol why register an unwanted name?

 

[sean01]

we have a couple of 65mm kits running.
1. yx150 (none upgraded case) with 65mm ceramic bore
2. yx150 (none upgraded case) with 65mm ceramic bore and cnc 59mm stroker crank..
3 zonger 155z (none upgraded case) with 65mm ceramic bore and cnc 59mm stroker crank. (only about 10hrs old now)

1 out of the 3 are still running (the 155z)
none have cracked a case as there always carefully kicked.
the 2 150's run yx150 heads and the 155z is running the zonger head
all running 28mm oko's and standard cams..
plenty of grunt but they all could do with a v2 head..

now after trialing these ceramic bore kits i have come to the conclusion that there absolute rubbish, well the ones we got anyways...
the 2 tht have died have removed chrome off the bore at the top(approx TDC) they still ran but blew still loads of smoke..not to mention the oil rings collapse.
both these engines lasted about approx 60-80 hrs

EPOD.. the CC's you mentioned are way off...
and NRG(aka tool) yx150 has 53mm stroke, and you go to the trouble of mentioning compression ratios but not sign's of CC'ing the head or high comp pistons..

so please everyone disregard his babble..

yx150 with 65mm bore kit and 53mm stroke is 175.87cc
yx160 with 65mm bore kit and 57mm stroke is 189.14cc

now also all these engines run standard clutch kits. the only one tht has had a drama is the 175.87 engine, it stripped teeth off and killed the rubber dampeners in the basket..

oh and EPOD download ya self a copy of Virtual engine calculator. Virtual Engine Calculator Free Download

works everything out for you man

 

[epod]

Thanks

Thanks Sean for the correct measurements on the cylinders. My math was never that great. I am actually glad it will be a 189cc. These are all my numerolgy lucky numbers. lol
I will be running a alloy cylinder with steal sleave.
80 or 90 hours is not to bad considering those cylinders only cost as much as a top end pit for a jap bike bike.
Cheers for the info on the clucthes. I have 2 spare baskets near new. So should not have to spend any more money on the clutch for a while.
Ride on, DD

 

[sean01]

yep, all good man.. and good luck, you will have fun..

and yeah a steal sleeve should be heaps better...

 

[grnman]

ive seen a 155z with a 68mm bore making it 200cc on the motard track i go to Epod. its really fast. his clutch couldnt take it but is was just a spring thing. he got off the thing and kept saying 'thats 650 Sh11t man....thats 650 Sh11t' so i think he was impressed with the power.

you should be to