Stiff Varitor and other problems...

Hey, yesterday I fitted a polini 70cc kit, new variato and carb and other bits and bobs. I don't have a kickstart so I depend on my electric start only. This is the first scooter I've owened and the first engine I've worked on and to the best of my knowledge it was fitted fine.

Now heres the problem. I checked to see if the new kit turned over by turning the variator pully, and it does it smooth and effortlessly. But as soon I put in the sparkplug on certain parts of the stroke its quiet stiff. I put this down to compression and thought not much of it.

But now the electric start doesn't have the power to turn the variator pully. So something can't be right. Any help would be wonderful. Thanks

 

just check you've put the right spark plug in might be too long ? or it could be the kit having more compression making an old starter motor struggle
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Thought I'd add that it might be that I haven't attached the variator and that perfect, and the electric start bounces off the pully for a couple of seconds before it catches.

So the problems with either the kit of the variator pulley, or even the electric start. But I'm stumped as what to do, is it normal for it be stiff at certain points with the plug in, but not with the plug out???

 

I've checked to see if its hittin the spark plug and I'm confident it isn't. It could be an wearing startor motor but it worked perfect with the 50cc kit, and I've never heard of somebody having to change their startor motor to power a 70cc kit.

I'll try the electric start without a plug, see what happens... Can't do it tonight thought so keep the sugesstions coming!!! Many thanks

 

Just read this on Bell Rock Racing

"The electric starter on the SR couldn't cope with the larger compression on the 70cc racing kit I'd fitted, so I would have to kickstart at least 5 or 6 times to get it to go, with the Splitfire on the other hand, the SR would start first kick come rain or shine."

So it's not just me, looks like I'll have to fix my kickstart, can somebody who's changed a cylinder kit please confirm that it can be stiff at certain points in the stroke, because I really don't want to put in the kickstart, kick it, fuck it up and then be told I shouldn't of kicked it if it was stiff. Many thanks

 

it should really make much difference, ive got a rep kit and my bike starts with just the tinyest of touches to the button.

if it worked before then its something youv'e done!

sounds more like the variator ent on properly so sort that out first, then with a freshly charged battery try again, if its still struggling to turn over then check the motor itself.

if it turns over freely by hand then the bore should be fine, and yes they do get 'stiff' but that is compression and the laws of physics.

if i was you id fuck the motor just stick a kickstart on it and get it started!!!

best of luck mate

 

Yeah cheers for that mate, I was kinda leaning towards it being the variator side of things.

Waiting for the new kickstart gear to arrive, gonna take about a week. In the mean time I'll charge the battery again the rebulid the variator and that and try again.

Not sure what I could of done wrong, I added some washers because orginally after adding the new variator the variator pully caught on the electric start constant, maybe I've got it sticking out to far, but I'll find out eventually.

Just a question when people talk about allinging the pullies in the transmission, do they mean the one's furthest from the engine, because I wasn't entiliey sure what I was meant to be allinging. Cheers

 

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baz172 Posted: Thu Jun 26, 2008 6:38 pm

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just check you've put the right spark plug in might be too long ? or it could be the kit having more compression making an old starter motor struggle
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^^ thats a good point or you crank might be seazin put a kick start on it and kick it

 

my 70cc aerox has the same problem but it starts fine once the engines warm.

 

might just need running in? or try your oringinal variator on it

 

i was told some 70kits are to heavy for the standard starter ???? ive also tried a spare starter and that was the same.

 

What did you set the squish at?

 

what the hells that lol

 

Basically the gap between the piston and the head, it sets your compression ratio.

You use base gaskets to alter the height of the cyl thus adjusting the comp ratio.

 

dont hav a clue the lad i bought the ped of has had all work professionally done by a garage. it makes 130psi though.

 

didnt think of the squish, pop the skull off and check the level