Arreche 19mm carb tuning

[zombie]

Hey man. Sorry it's been a while. What kind of bore kit did you use? Did you contact the manuf? Seems to me there has to be a wrong part mixed up in there somewhere! Not trying to panic you but you should not have an interference issue w/ a new kit. Also I didn't notice if you worked on the variator/ clutch. They will give you the 50- 55 mph mark. I'd double check the jug kit just to sleep well. Just another thought, If you raise the jug, you are also raising the ports w/ it. That will have a small amount of difference in performance. Most likely not enough to feel, but when you are squeezing tiny amounts of HP at a time It all counts. Keep posting because this has turned into basicly, a full system build overview. Good luck Bro.

[Shaka]

Zombie-  I got the kit from moped hospital.  It is an Airsal 46mm jug.  Everything I have come across points to that being the correct kit.  The manufacturer number matches with what I have run across from other suppliers as the correct kit.  When I got it Steve at moped hospital told me to use two bottom gaskets.  He said the Honda Dio uses one, but the zx50 uses two.  He actually forgot to send me two to begin with and I had to call him because the piston was hitting pretty badly after initial installation!  This is when he told me I needed two gaskets, and he sent me another.  When I put the other gasket in it seemed to be better, until I got it spinning fast enough.  Then apparently is was just barely touching.  There doesn't appear to be any damage.  The piston just had a small silver ring around it where there was no carbon build up.  It sounded way worse than it was!  I thought about the port timing. I guess that is another question I need to address.  It is such an insignifigant amount that the jug is raised, maybe 2mm at the most.  Could be enough to make a difference though.  As for the variator and clutch.  I am still running the stock ones, but have installed 6.5g rollers, down from 8.5g, and stiffer clutch springs (green).  These came with the kit.  I am also running a Malossi kevlar belt.  Could this be what is holding back my top speed? I also got a chance to mess with it a bit today.  I tried the needle in the middle and fully raised position.  It bogged out pretty badly.  It wouldn't even idle with it raised all the way.  I put the needle back in the lowest position and it ran alright.  I played with the mixture screw and still couldn't get the top speed any higher that about 42mph.  It accelerates way faster than it used too, but I had a higher top speed before I did any of this work.  Something is just not right!

[zombie]

Hey shaka, Do you still have the stock belt? I am running all malossi prod. in mine, and the variator is a different diameter than the stock unit. your malossi belt may be too small to get topped out. also there is another post (I think in the zx/50 forum) about removing a spacer washer behind the  stock variator. IF the malossi belt is too short this may give you some extra room. I thought these things were supposed to be FUN! Oh well.

[Shaka]

It is fun when I'm riding it, not working on it!  As for the belt, I still have the stock one, but it is very worn!  I do recall the malossi one being a little bit shorter.  I replaced the belt right before I did the rest of the kit and it went about 44mph on the flat and 48mph downhill with the stock motor.  This leads me to believe that the belt, variator, and clutch are not the culprit.  When I bought it used the dealer removed the washer in the variator, so it's not that.  I think it is the carb.  I rode it to work and home today and it just seems to be possibly bogging out.  I'm going to try swapping the jet out for a smaller one.  I haven't tried anything but the 130 since I put the 130 jet in.  Now that the clearance issue is remedied it might run better with a smaller jet, hopefully!  The other thing I was thinking is that the combustion chamber is slightly larger now with the extra head gasket.  This may be the reason why I need to almost start over on tuning it.  I need to get some more spark plugs to do some more chops.  And more free time to mess with it!  At this point I have about a dozen spark plugs I used for previous chops.  Can I reuse these for another run?  They are all very clean looking still as it was running lean before, and I only used them for about 1/2mile each.

[zombie]

Yeah Bro, Reusing the plugs is fine, Just give it a few miles to take a new reading. It all makes sense. You were chasing a pre ignition problem w/ jets, only to find it was a clearence problem. You prob are too rich on the jet now. Funny thing, I took off my cyl. head after posting , and getting back in the mood to trouble shoot mine somemore.  I put on the new regulator, still had good spark, still was getting fuel, still no start! pulled the head , and found a pin hole in the piston. you cant get a sewing needle through it but turned upside down fuel just runs through. No matter how many times you think you got it down and don't need to look there/ there it is. I also lost my key, go figure. Thanks for ALL the help along the way. When I get this thing put back together I'll post a few Pict's.

[Shaka]

Zombie- That sucks!  I guess it is a good thing that you found the problem though!  Hopefully, that is the only thing wrong!  Good luck! 

[Shaka]

I got some time this afternoon to do a little more tweaking.  It has been bogging all week with the 130 jet installed.  I also noticed that there was a "sweet spot" in the throttle between 1/8 and 1/4 throttle.  If I just held it there it would run at a faster top speed than anywhere else, kinda weird, but makes sense with the jet too big.  It was a little scary a few times while decelerating I would run back down past this point and it would take off on me again!  Anyways, I down jetted today and ended up with a 115 installed currently.  That took care of my WOT bogging at smoothed out the entire range of the throttle.  Now I'm getting a top speed on the flat of about 47mph.  Still seems a bit slow for my setup, I'm going to check the belt and variator next time I get a chance and make sure it is operating correctly.  I'm gonna run this 115 jet for a few days and see how it goes.  Will post updates, any input would be appreciated.  Anyone else running  a similar setup?  What kind of a top speed are you getting?