pk80 or gt5 .160 piston fit in raw motor .100 piston with manic mechnic head ? HELP

R

riff44raff

New Member
I bought a manic mechinc gen 2 head . the add said it "will work with pk 80, gt5 and raw motors 80/66cc" but it only works with a .160 crown piston motor . well my raw motor has a .100 crown piston my luck . anyhow I realy want to try this out I like to go faster and dont want to ship it back . so can I get a pk 80 or gt5 (or any ) .160 crown piston and put it in my raw 80/66cc .100 crown piston motor if I use the manic mechnic head ?????????????? also where can i buy a .160 crown piston that will fit or where can I buy a pk 80 motor ??? thank you
 
Re: pk80 or gt5 .160 piston fit in raw motor .100 piston with manic mechnic head ? HE

riff44raff said:
I bought a manic mechinc gen 2 head . the add said it "will work with pk 80, gt5 and raw motors 80/66cc" but it only works with a .160 crown piston motor . well my raw motor has a .100 crown piston my luck . anyhow I realy want to try this out I like to go faster and dont want to ship it back . so can I get a pk 80 or gt5 (or any ) .160 crown piston and put it in my raw 80/66cc .100 crown piston motor if I use the manic mechnic head ?????????????? also where can i buy a .160 crown piston that will fit or where can I buy a pk 80 motor ??? thank you
Click to expand...
Are you sure you are measuring the piston correctly? [SEE PIC]

I have an older RAW motor that has the 0.160 piston.

You need to make sure that the deck height is correct too.
INFO

PISTON1.jpg
 
Re: pk80 or gt5 .160 piston fit in raw motor .100 piston with manic mechnic head ? HE

thank you for the reply and honestly no I dont know how to get a accuret mesurement can you explain basics do I use a stright edge and top out the piston then go from there ? I got a cheep calipers I took a few pics I will try to post but it looks almost flat to me
 
Re: pk80 or gt5 .160 piston fit in raw motor .100 piston with manic mechnic head ? HE

riff44raff said:
I bought a manic mechinc gen 2 head . the add said it "will work with pk 80, gt5 and raw motors 80/66cc" but it only works with a .160 crown piston motor . well my raw motor has a .100 crown piston my luck . anyhow I realy want to try this out I like to go faster and dont want to ship it back . so can I get a pk 80 or gt5 (or any ) .160 crown piston and put it in my raw 80/66cc .100 crown piston motor if I use the manic mechnic head ?????????????? also where can i buy a .160 crown piston that will fit or where can I buy a pk 80 motor ??? thank you
Click to expand...

I've just bought the same head. Holding an electronic caliper up next to the piston you can get a pretty good idea if it's .100" or .160"

You're going to need some mearsuring tools, because we're going to have to set the squish.
 
Re: pk80 or gt5 .160 piston fit in raw motor .100 piston with manic mechnic head ? HE

allright biknut I guess I got to go digital any sugestion on a dicent set for cheap ? and I am guessing the .160 and such is metric ? but they should come in What metric and standard ? funny thing is I have allways worker on my cars bikes motorcycles ect my whole life but never got into them like pulled the heads crack the cases because I never had access to the big tools/machines but these china motors are so small I can use my dremmal so if you can please walk me through this I will appreceiatei it so first ?? is calipers where and look for what and second ?? whats .160 .100 ect metric ?? hundrith of an inch or some straing china thing that we shoulnt be alloud to have olny in calif ??
 
Re: pk80 or gt5 .160 piston fit in raw motor .100 piston with manic mechnic head ? HE

You're in luck, because right now the market is flooded with cheap digital calipers for $20 and under, that are very accurate compared to our needs. Try harbor freight or almost any hardware store.

The piston top is measured in inchs. The Gen II head appearently calls for a 0.160" crown. Eye ballinng mine with a caliper, looks like it's probably .160" if there's only 2 choices. I know it's not a flat top lol.
 
Re: pk80 or gt5 .160 piston fit in raw motor .100 piston with manic mechnic head ? HE

you got the caliper eye ! hay at least its better then my idea I just put it on and rolled the bike slow to see if I could hear anything hitting and I assumed I eather have the right one or too short and ya the raw motor I got looks .100 almost flat I will get the calipers and check but I d bet its .100 so i will get back to you in a day or 2 but can I take a .160 piston from a pk 80 or gt5 and use that ?? and where can I get one ? in fact where can I get a pk 80 ??? again thank you
 
Re: pk80 or gt5 .160 piston fit in raw motor .100 piston with manic mechnic head ? HE

riff44raff said:
allright biknut I guess I got to go digital any sugestion on a dicent set for cheap ? and I am guessing the .160 and such is metric ? but they should come in What metric and standard ? funny thing is I have allways worker on my cars bikes motorcycles ect my whole life but never got into them like pulled the heads crack the cases because I never had access to the big tools/machines but these china motors are so small I can use my dremmal so if you can please walk me through this I will appreceiatei it so first ?? is calipers where and look for what and second ?? whats .160 .100 ect metric ?? hundrith of an inch or some straing china thing that we shoulnt be alloud to have olny in calif ??
Click to expand...
0.125" = 1/8"
0.0625" = 1/16"

0.160"
-0.100
------
=0.060" difference which is a bit less than 1/16"

You really don't need calipers.
Click on the pic above to see the bigger size.

Once you get the right piston height you still need to measure the
deck height and maybe sand some material off the top of the cylinder.
 
Last edited:
Re: pk80 or gt5 .160 piston fit in raw motor .100 piston with manic mechnic head ? HE

ya it looks like I got the wrong piston and for sure i will have to do some sanding .03 is what 1/32 ?thats thiner them the gaskit . do you think I can just change pistons ?
 
Re: pk80 or gt5 .160 piston fit in raw motor .100 piston with manic mechnic head ? HE

I fitted one of the Pirate heads (MM clone) to a older Raw engine with good results... I know that the newer Raw engines can have totally different parts than the older ones, so you have to measure carefully before ordering. :/
 
Re: pk80 or gt5 .160 piston fit in raw motor .100 piston with manic mechnic head ? HE

I kinda like that older original Pirate's head style it has a better classical look on the board trackers and the like.
 
Re: pk80 or gt5 .160 piston fit in raw motor .100 piston with manic mechnic head ? HE

A couple weeks ago I bought a 80 cc cylinder and piston set, from BGF. I just checked it and the piston dome is 0.160

It was $35 w/free shipping
 
Re: pk80 or gt5 .160 piston fit in raw motor .100 piston with manic mechnic head ? HE

thank you guys for all the info ! so can i buy a piston with the .160 crown and put it in my raw motor if I use the new head ??? my raw motor has a .100 crown also any advice on sanding the barrel down ??? thank you
 
Re: pk80 or gt5 .160 piston fit in raw motor .100 piston with manic mechnic head ? HE

You can use the head in the engine with a .100 crown, it will run fine, but for maximum compression, you would need the .160 crown.
 
Re: pk80 or gt5 .160 piston fit in raw motor .100 piston with manic mechnic head ? HE

hay thank you for the info and I went and tryed it out and I could not get the motor to start it uasualy stars right up with the stock head . with the M M head it wanted to fire but nope any ides advice I have been told piston bikes sales a .160 crown piston I am not sure if it will work but if it fits the bore it should be ok with the M M head and I will have to get the deck might right .let me know what all of you guys think ! any advice ? thank all of you ps the motor wont start but wants to it feels like not enough spark or if I could get going faster it might but thats just how it feels and I am going as fast as I can .thank you guys
 
Re: pk80 or gt5 .160 piston fit in raw motor .100 piston with manic mechnic head ? HE

Sounds like mebbe your head gasket seal is not right? I mean if the only thing you have currently messed with is the head? That puppy should start right up! Mebbe double check you did not crack your spark plug try a known good spark plug double check the spark plug wire etc.
 
Re: pk80 or gt5 .160 piston fit in raw motor .100 piston with manic mechnic head ? HE

ya did that I put the old head back on and fires right up
 
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