72cc or 80cc?

[Kenho21]

So its crunch time buying my new kit tomorrow but having trouble finding the kit I want to go with. I'm leaning toward a 72cc kit rather than 80cc because I will probably get more life out of it but I have three questions.

1. What are good brands to look for? I saw airsal and think they may be good?

2. Will there be much difference between a 72cc kit and a 70cc kit? probably not I know especially if the 70cc is a better quality...

3. Anyone here have experience with this and give me any tips on what to look for?

[Kenho21]

Also, the 70cc Airsal kit is aluminum. Would this eventually cause damage between a steel head and engine block?

[thebatman]

Airsal is real good quality stuff.. you just have to be more careful with the aluminum, they can ruin alot easier than cast iron... Malossi is another top dog.(it's what i use on 2 of mine atm)...polini is good but it's higher also.... To many bad words have scared me from anything else "ncy"..... some ppl say it's ok stuff, but i know ppl used there stuff and swear it's crap....
Actually if you get a 70 kit, your scoot will be 71.8cc in the end so a "72" kit would only be like 73.5cc and no the aluminum wont damage other parts unless under abuse it's possible...lol

[Kenho21]

Thanks, I was just worried about the aluminum responding differently to temperatures than the cast iron is sandwiched between. I think the 70cc airsal is the winner.

Will my 80cc cam run alright with it, I've seen advertised on some websites the use of an 80cc cam with a 70-80cc ki

I also have a 85cc 52mm head layin around, that wont do any good on my 70cc kit will it?

[sidthesloth]

I think you will find that your crankcase and head are also aluminium. The aluminium cylinders are supposed to be good, I believe the cylinders are coated with a harder surface treatment to withstand the friction. The only problem is that if you do damage it I am of the impression that it is then disposable, others with more knowledge will be able to add more/correct me. With cast iron, if you damage the cylinder with seizing you can run a hone through to clean up the bore and reuse it, this gets my vote.

[thebatman]

Yeah, the cam should be good to use...
IDK about the head though.. the kit is smaller than the 52mm head but it's worth a shot to look and eye it good while she's apart ..

[thebatman]

Yeah, sid's correct on the cylinders.... On the aluminum you'd have to have the nicasil recoated,etc. etc. if it's not TOO bad, otherwise it'll be a paperwieght... I'm with sid, cast iron for a street scoot..

[Kenho21]

Much appreciated! I think I'm just gonna go with the cast iron then. Now I just gotta find the right one with a balance of quality and price. Tryin to stay away from the chinese stuff...

[baddi]

I believe that alu would suffer from corrosion when touching iron, and as aluminium expands when corroding, i think that  the best solution would be to use a cylinder in the same material as the rest of the engine, even if the aluminium is coated with something to prevent corrosion.