yx 150cc to 170cc Questions

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J3NNINGS_024

J3NNINGS_024

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hey guys, im thinking of turning my yx 150 (klx style) into a 170 and ive got a few questions.

1. has any of you guys bought the TB 170 kit and if you have, whats it like?
2. can i turn it into a stroker, with the works yx 160 short crank off TBoltusa?
3. if i can turn it into a stroker, what do i have to do to make it a stroker?
4. will the updated crank case fit a yx 150?
5. can i upgrade the bearings in the cases or are stock one's fine?

any help would be great.

cheers, Brad.
 
ok, the yx160 crank will go straight in but depending on the engine you have a clutch cover may be required.(i have done this myself in the past)

the yx160 crank is a short crank meaning it doesnt run an oil slinger. there was a batch of yx150's that also had the short crank but you will need to verify this by removing the clutch cover and finding out if an oil slinger is present..
Works YX160 57mm Short Crank - Pit Bike Engine Parts - Parts & Kits ZS 155cc & YX160 - Works YX160 57mm Short Crank - TBolt USA, LLC

if you need a clutch cover you can see in bold on the link that they use is Works YX 150cc DTE-5 Clutch Cover (Daytona Type) - Pit Bike Engine Parts - CLUTCH KITS - Works YX 150cc DTE-5 Clutch Cover (Daytona Type) - TBolt USA, LLC

also you need to work out if you want the yx160 crank in there before choosing the big bore kit, some are specifically for yx150 and some specifically for yx160
TB YX150/ GPX 170cc KIT - TB Parts - CHINESE ENGINES - TB YX150/ GPX 170cc KIT - TBolt USA, LLC
TB YX160/ GPX /OGM 184cc KIT - TB Parts - CHINESE ENGINES - TB YX160/ GPX /OGM 184cc KIT - TBolt USA, LLC

some require your engine cases to be machined out for the new over-sized barrel.

the updated crank case and gear set will swap straight over and is recommended if you are increasing the engine size... if you dont do the case swap then at least put a decomp cam in it or one of the other options..

bearings are generally fine but upgrading to high quality jap bearing is always good..
only problem is there not all that readily available..
look in my sig for a link about bearings..

also, if you are going a big bore kit then i would advise that you also install a V2 head for best all round performance.
the big bore kit alone will only offer more low down torque and most of the potential power is wasted because the standard head doesnt have big enough valves..

to give you an idea, it will pull like a tractor down low but only be marginally stronger up top..
also remember that by increasing the engine size the camshaft duration will change..
IE: a standard cam will allow the engine to rev less with a big bore kit

this may all be too much info for what you want to achieve but at least you know ;)
 
ahhhhhh thank you so much sean, your are bloody legend:clap:. yeah my engine does have an oil slinger. Does that mean i have to get daytona style clutch cover? it'll be great if it does cus this dirtmax one looks crap. i got the stock head ported & polished and it has the de-comp cam put in too. so wil the 160 short crank work with the 170cc big bore kit? or only the 184cc?
 
id say the since the 170 kit is a shirtless design it wont work with the 160 crank as the piston will more than likely travel further than the bottom of the barrel.

but dont take this as gospel, email tboltusa and get them to confirm. they ll be able to answer any questions you have and hook you up with the needed parts..

and yeah the daytona cover looks alot better than the shtmax one..
 
yeah i'll email tbolt tonight. ok, the 184cc kit wont fit a yx 150 so could i use the 160 short crank on the stock cylinder? i really want the engine to have a heap of torque cus the 53mm stroke is horrible.
 
yep short crank is compatible with all the standard items apart from the clutch cover...150 bore, 150 piston, 150 head..
and you will actually bump the compression up to a nice level using the 150 head..

you may be able to get a 160 long crank off ebay aus
 
got a reply from tbolt today and he said that the 160 short crank will work with the 170 big bore kit. the only reason the 170 cylinder is skirtless is because of the smaller spigot hole. looks like ill be getting a longer stroke and a bigger bore:D
 
if ya want a cheap deal on the crank and case alexwarehouse.com do both for around $130 delivered. i just got a crank and case recently from them comes with no filter though i used one from a yx external oil filter comes with the spring needed aswell ($20 off ebay), also you need the cable bracket and and a few longer bolts. if you do buy from them make sure they give you the little glass window oil level reader they just sent me one for free since they had none in stock when i bought the case and crank.
IMG_32492.jpg


if you do go that route you have to mod the head oil feed tube the the case and block the bottom outlet off like the picture
below and then run the cooler lines from the case.
195002.jpg
 
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saga.. did you get all the accessories for the clutch cover too, like oil level glass, kicker seal, oil filter and cover and so on?
 
sean01 said:
saga.. did you get all the accessories for the clutch cover too, like oil level glass, kicker seal, oil filter and cover and so on?
Click to expand...

no oil filter or kicker seal. the seals are the same as old style case so you can swap them over aswell as clutch arm and comes with oil level glass and covers in the picture
 
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or do the cheaper option and buy a 160 motor and get the bore kit at the same time save you having to split cases then u get a new updated motor
 
fiffty _boytim said:
or do the cheaper option and buy a 160 motor and get the bore kit at the same time save you having to split cases then u get a new updated motor
Click to expand...

i already got the engine striped down to the cases because of a stuffed shift drum so i might as well build up a better, faster engine while its apart.


if ya want a cheap deal on the crank and case alexwarehouse.com do both for around $130 delivered. i just got a crank and case recently from them comes with no filter though i used one from a yx external oil filter comes with the spring needed aswell ($20 off ebay), also you need the cable bracket and and a few longer bolts. if you do buy from them make sure they give you the little glass window oil level reader they just sent me one for free since they had none in stock when i bought the case and crank.
Click to expand...

cheers saga, ill look up alexwearhouse. only $130 delivered? that'll save me some money for other mods:action-smiley-033:
 
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