CDI Limiter?

[meatshake]

Hi all

I have just bought a bullet 50 that was in the middle of a 70cc kit, and subsequently is not running properly right now..

I have been reading about this cdi limiter and I am wondering how it works.

If it is supposed to cut revs over 8000rpm, if I have the bike on the center stand and rev it out, the revs should not pass 8000rpm...

Is this correct?

[harry]

more like 9,000 -- 9,500

a half finished mod is suspect  i'd check everything if i was you.
 its so easy to put  the piston  in wrong(turned 180) as well as the rings
or a 'c' clip which would ruin your motor in the first  ten miles.

oilyhans

[meatshake]

I agree with that suspect part! the is pop rivots everywhere and dangly bits and all sorts...

I plan to rip it apart this weekend and access what it needs.. I was a bit concerned when I read the possibility of a cdi rev limiter, but this thing revs out to 10,000 on the stand no problems So I guess that shouldn't be an issue.

Also it does run right now, it just doesn't feel much better than my vmoto milan with a zx pipe.. So I think something is a miss.

I have jetted up the carb with some jets I had around to a 85 (from a 70) and this seemed to have fixed a bit of spluttering, but it still feels very sluggish.. fun times ahead!

[kennedyrd]

9000 rpm on my Bullet RR. Tried one of those 5 pin "racing CDI with advanced curve", but seemed down on power, then after two or three runs just wouldn't start. Into the bin! Going to try some other brands.

[harry]

 as you might know a un limited or un restricted cdi
 will allow the motor to turn faster ~ more rpms
however you need to develop higher rpms  like with a bbk , pipe or bigger carb.
to really make any real difference  in top end speed

oilyhans

[kennedyrd]

Thanks for your input Harry. Yes, it was after fitting my Technigas pipe I noticed the "problem". I thought it was rich but after trying many jets realised it was a limiter. I know what too rich is like and it was not that!  Unfortunately the aftermarket CDI unit I tried stopped working before I installed the pipe. I tried to cut the "brown wire" on my standard CDI as I see in some forums but then it wouldn't even start. I was optimistic it may have been unrestricted!

However even when I do install the 70cc kit and 17.5 mm carb I might well leave the rev limiter in place to preserve the weak crank I hear about on these Morini based motors. I suspect the motor will be "revved out the back door" even at 9000 anyway as the standard peak power is at 7500 and the Stage 6 70cc kit may well be similar in it's power band, as I chose it for it's advertised "tame exhaust timing".  If I want more top speed I will install the Polini gear set I see available. It is really only an around town scooter so even now it has the speed and power to pass cars!

Having my GP bikes I know how high maintenance highly tuned 2 strokes can get (top end rebuild every 600km and crank at 1500 km) so don't want my scooter like that!

[harry]

your right at  looking at a gear kit upgrade.
that is the best way to get the best top
end and is the easiest on the crank .

and yeah over tuning can wipe a crank out in a
very short time.

oilyhans

[meatshake]

oh wow.. this is a while ago now! turns out the scooter I had had no rev limiter and was just a tuning issue with the carb causing it to crap out early.