engine mod guide

[Sharkey]

going to pull my cy26 apart this winter to have a look at it and am thinking of doing some mods. possibly a stuffed crank, ceramic bearings, low drag seals, etc. im also thinking about porting it, ive got a set of dark soul port templates on their way.

im looking for some info on internal mods for these motors. i know tuners are pretty tight lipped about what they do, but im sure there is some info online somewhere about porting, port timing and compression, i just cant seem to find it. anyone have anything?

 

[pablo]

its best to try and get your hands on a tuned head even if its blown you can still get the basic ideas from it. i used an old 23cc head to practice on but then never got round to using it. instead i just went for the bolt on option of a 30.5 kit with stuffed crank fast eddy bearings and a dom pipe.

 

[marderdeej]

its best to try and get your hands on a tuned head even if its blown you can still get the basic ideas from it. i used an old 23cc head to practice on but then never got round to using it. instead i just went for the bolt on option of a 30.5 kit with stuffed crank fast eddy bearings and a dom pipe.

hi pablo, just wondering what sort of money i could expect to pay for a 4 bolt head in new condition? also how does it bolt to bottom end if mines only a 2 bolt block? sorry for my nievety buy im relitivly new to fg's although iv had quite alot of 2 stroke bikes

 

[46u]

One thing I recommend doing is torque all engine fasteners to manufacture specifications. In my opinion mandatory on a 2 bolt cylinder bolts.

Here is a thread with some help full information.
http://www.hpibajaforum.com/forum/showthread.php?t=83403

 

[pablo]

a 4 bolt head won,t go on a 2bolt crank case. my motor is a 2bolt but as 46u says you must use a touqe wrench to clamp the head down. i used a k,m 30.5 kit which comes with a 2mm stroker stuffed crank it cost £55 and the k,m dom pipe another £50 the bearings and new seals £20, i allready had the c,y casings so the whole motor cost around £125. its a bit of a watch this space at the moment tho, i,ve only had 1 tank of juice thru it but it ran very well but i do have a bit of history with motors going pop. theres 4 bolt 29cc engine kits on ebay under the hpi section think there about £70, but if you,ve got tho money just get a zenoah 29cc 4bolt complete motor, there awsome.

 

[Sharkey]

thanks for that link, tons of useful info there. i think i need to pull my motor out and apart and start measuring.

 

[marderdeej]

a 4 bolt head won,t go on a 2bolt crank case. my motor is a 2bolt but as 46u says you must use a touqe wrench to clamp the head down. i used a k,m 30.5 kit which comes with a 2mm stroker stuffed crank it cost £55 and the k,m dom pipe another £50 the bearings and new seals £20, i allready had the c,y casings so the whole motor cost around £125. its a bit of a watch this space at the moment tho, i,ve only had 1 tank of juice thru it but it ran very well but i do have a bit of history with motors going pop. theres 4 bolt 29cc engine kits on ebay under the hpi section think there about £70, but if you,ve got tho money just get a zenoah 29cc 4bolt complete motor, there awsome.

thanks for that,
:lol:i cant spend anymore money on it at minute, but im thinking of swapping a few bits and then selling the mt and then il be able to spend a bit on the beetle, id like a new shell what i can paint myself,some alloy hubs,and a few other things before i start on engine,plus mines a 26 and goes well and its been reliable up to now,