How fast should my ZX50 be going after mods?

[Shaka]

HaHa!  Doesn't sound very pleasant to me!  Yeah, i see it, your burgundy/red color looks soooo much better!  I still have not received my jets!  I like how overnight shipping turns into 3 day!!!  It has been at my local post office since 3:17PM Saturday!  It was supposed to have Sunday delivery also according to the USPS website.  I called them this afternoon and they said it is an additional $12 for Sunday delivery!  WTF!!!  Still haven't figured out how/if I'm getting to work tomorrow!

[zombie]

Man That sh*t BITES. They charge, and charge, and charge! You still get squat...30 bucks to get 9 dollar jets,and you still can't roll

[wordslinger]

It's kinda sorta like being in a fat mans arm pit all day. Can you see the zx/50 headlite on the Ebay add? that's the color mine was...

..I lived on Fort Walton beach for a year or so when I was 11...It was niiiice...What wasn't was the year that I lived in central georgia...talking about a fat man's armpit...we had pet names for the mosquitos...killed small animals to offer them a blood sacrifice just to keep them away...





..no, really....






 

[zombie]

Yeah ,the only thing that really bites here is this area has been so secluded for so long, It's sort'a like living in the 1840's. Just ain't got much uuu's fer any o dat fancy New York lernin. The two high points of Franklin county are true! Highest per capita drug arrests in the state of Florida, and lowest unemployment in the state of Florida. Imagine 4,500 drug addicts that have NEVER had a job! This is MY pain. I was also wondering why there are no squirrels around here! Ps. there are 12'500 people in Franklin

[Shaka]

Dang, must be bad if the squirrels don't even want to live there!  I can assure you I have plenty here!  I sat on the back porch all summer and shot the ones in my vegetable garden!!!  Little furry rat bastards!!! 

I got a ride to the post office first thing this morning, I actually got there an hour early, can't even get the time right over the phone!!!  Anyways, I picked up my jets and rode my bike home.  I tried the 30 first, and it was too big.  I pulled the whole thing back apart and put the 25 in there, seems to work well!  I have a nice responsive bottom end, with adjust ability with the mix screw.  The mid-range seems good.  Still no top-end though!  It accelerates nice and quick up to about 40mph, then tops out at about 45!  I just don't get it!!  I was hitting 50mph pretty easily before I did the manifold!  Frustrating!!!!!

[wordslinger]

..well, at least you're up and running again..that's a good thing!!

..don't know much about your 2-strokes tho...

[zombie]

W/ the larger intake I would assume a larger main, and drop the needle down 1-2 to keep the mid range. perhaps a plug chop at top end? If you can't get it back there your reeds may be too stiff.Like slinger said, at least your running. Getting the main jet, and the right needle poss. is where I had the toughest time of all. I did the best I could get by over jetting to be sure, went back to the good size, then started on the reeds. they took an idle circut adjust, and 1 spot up on the needle. It just don't end!!!

[Shaka]

Yes- very happy to be back running!  Thanks for the tips Zombie.  I haven't messed with the needle yet.  I think from the short ride on it today that I may need to raise it and put in a smaller main jet.  Only plug chops will tell!!!  I don't even know where to begin with the reeds, it might help if I know what reeds where in there.  I may try and talk to Steve at Moped Hospital about it.  I should get a chance to mess with it a bit tomorrow.

[Shaka]

I got to put a little mileage on the scoot today.  It seemed like it was running rich, but wasn't too bad.  Still only hitting about 46mph though!  I managed to do one plug chop, which looked ok.   This was with a 25 pilot, 115 main, and needle all the way down.  I raised the needle on notch, and my mid-range was gone!  Totally bogging, until I opened it all the way up.  Then I switched out the main jet for a 110, and it seems to run much better!  The current setup is 25 pilot, 110 main, needle in the middle.  I'm still only getting about 46mph, but the scoot seems to be running well, sounds like I got the rpm's up a little at WOT.  I'm going to run it like this tomorrow and see how it feels. 

I think I may have narrowed down some of my loss of top speed to the reed valve, as this is the only thing that has really changed.  I did notice that the reed block that came with my manifold doesn't have Viton coated reed seats.  I'm wondering if they aren't sealing closed completely, but I don't know what a symptom of that is.  Also, I don't know how to tell if the reeds are too stiff, or too soft.  I have been looking at the Malossi reed cages.  The VL15 looks to be about the right size, and it's completely Viton coated.  I will probably contact them to get the dimensions.  As for reed thickness, I have read that thinner is better.  Basically, go as thin and flexible as possible, without sacrificing durability. 

I have also been thinking about the CDI.  I'm wondering if going with on that has a different timing curve for high rpm's would help get the rpm's higher?  I'm running the stock CDI de-restricted, which I'm assuming runs the same timing from where it is restricted (35 mph) up to as high as my motor will rev.

Any input is appreciated!

[zombie]

Good to here you are back on LEVEL ground. Ok, my thoughts are: W/ the extra air the larger manifold CAN move I do believe it has to be a reed problem. To test if they seal you can put the piston at BDC. you will have to make an adapter that fits the spark plug threads, and has a Schrader (tire) valve in it. The Carb. has to come off though. you can use a small compressor to pressurize the block to 6 psi. That is the safe limit of the crank seals. Even a tire pump for a bike will work. the crank seals will blow under pressure because they are made to work w/ a vacuum, so don't pay too much attention to them. A little soapy water in the reeds will tell if they are sealing or not. An OLD SCHOOL trick is to use a razor blade to apply 3m 5200 (marine adhesive) to the cage. It is sorta like silicone only permanent. The reason I believe yours are too stiff is the idle jet is SSOOO small, and your reduced top end. The malossi reeds gave me the same symptoms you have now. A poor sounding low to mid and a lean top. Look at the Boysen reeds. They have been making performance reeds since somewhere around '70-72. Another point is if you torque the cage too tight it can deform. W/ the leak you had I think it may be another point to think about (as if you don't have enough on your plate)! Just thought if you do the first pressure check deal you may be able to HEAR the air escaping through the carb, especially if you can get some soap(dawn) down there. Might save you taking the carb off. And almost finally: Contact Suitai!!! They programed my cdi to the full blown cdi the factory used in '04. It was only 49-51 bucks to my door. That did give me alot more pep from low-mid to top. The idle suffered because the initial timing is 2% less than the "road" scoot. I assume this is done to keep things cool in a "race" scoot vs an every day warranty scoot. W/ the higher advance in the top end, you certainly need the extra fuel you can get now. There is a post in one of the other threads about a tuned Jonway self destructing after 1000 miles. I bought my scoot w/ 8000km , and just looked tonite. 41274. The SAME crank/con rod/bearings/seals/rear gearset/housings. Kymco ROCKS! No doubt. Ps. 2 1/2 years.

[Shaka]

I'm leaning towards the reeds being a problem as well.  I will try and come up with some type of adapter for the spark plug hole.  I don't quite understand how the process works though.  Essentially, I'm pressurizing the crankcase against the reeds?  The reeds should seal and hold back 6 psi?  But the crank shaft seals will not hold pressure, only vacuum, so how will I test the reeds?   Where does the soapy water come in?  Why do I have to take the carb off to do that test?  I'm confused, did I totally mis-understand?  I've seen the video from Aeromyst i believe, on the vacuum test, I get that.  I just don't get the pressure test.

 I'm pretty sure I took care of the initial air leak around the manifold.  I sealed all the joints with some marine silicone stuff.  I couldn't find the OMC Perfect Seal, but I think the stuff I used is same type of sealer.  I don't think the idle jet is really that small.  I think my Arreche jets are numbered differently than your Delorto.  Seems like Arreche may number by flow and Delorto by diameter.  The jet I used (25) is about 0.45mm.  Everything I've read says the stock 20 is almost always adequate.

I researched the Boyesen a little and couldn't find anything that looked like it would work.  I didn't look all that hard yet though.  The other problem is I don't know exactly what size I'm looking for.  I'm also not all that comfortable with cutting my own.  It seems like they have to be so exact!  I'd like to find some that fit right into my reed block.  I may just end up getting an entirely new block because I want one that has Viton reed seats.  Seems like it would seal much better!  I like the looks of the Malossi VL15, and I wouldn't have to use gaskets on either side of it from the looks.  That would eliminate the some of the hassle of pulling the manifold off to remove the carb.  The gaskets on the current setup don't fit all that well.  Actually, it's more the flanges on the current reed block aren't wide enough on the sides to make real good contact with the manifold flange. 

I'm going to definitely look into getting a new reed block, if nothing else, for a better fit and hopefully function.  Once I get that figured out I'll look into getting a custom programmed CDI.  I've also been wondering if the extra head gasket I used may have changed the squish band enough to lower my output.  I'm running 2 paper type base gaskets and 2 aluminum head gaskets on my cylinder to alleviate my piston/head clearance issue.  This may have every so slightly changed my port timing as well.  I've been thinking about making a thin aluminum spacer to go below the cylinder so I can remove the extra head gasket.  I don't really want to run 3 paper type base gaskets, but I could sandwich an aluminum one between 2 possibly.  Just more ideas, I swear I always thinking of different scenarios!   Like you said Zombie, get it running well with the current setup before moving on to the next phase!  Sounds like some good advice!

[Shaka]

I was just pondering this pressure testing procedure.  I would have to either plug the exhaust port, or I could pressurize through the exhaust port and leave the spark plug in.

[Shaka]

After riding to work and back (short distance)  I definitely need some more carb tuning!  I was bogging pretty bad all through the low-mid range!  I'm considering taking out the new reed block, just putting a gasket between the two manifold parts, and putting the stock reed block back on the bottom.  The opening for the stock reed block is just so much smaller, I fear that will cause issues also.

[zombie]

Hey shaka, Sorry for the delay. Gonna be soon ex-wife came in to tell me what a heartless turd I am while I was trying to answer you. I got a little distracted! You are right on the preas. test Just bolcff what you need to. The soap will help to give you a gurgle to ID the reeds if that's where the prob. is. You may be able to leave the cab. on I just think it will be easier to see first hand if the cage is twisted or if your reeds have a taper on them. The seals will blow by but if your reeds are leaking you will see that first. The squish zone shouldn't be a factor, and I think it is a great idea to have a spacer cut to fit under the jug to get the clearance. You could poss. do it all through the mail by sending a gasket to a shop that does water-jet cutting. I don't believe it would cost more than 30.00 bucks. The deal w/ the jet size makes sense (flow vs mm) so you should be alright there. Idle size anyway. That set up w/ the block/ manifold not mating well bothers me too. Maybe another call to Moped Hospital is in order. The parts you have gotten there seem to all have fitment issues. Everything can be made to work you just have to hit it one section at a time. Sucks it is your main transport! I tend to put projects up until the light bulb switches back on an the right idea hits. Maybe try to get it close to dialed in and start at the beginning again w/ getting the cyl. set up right. That way you have a chance to let the dust settle, and figure the next step. Having the extra pressure of tear down/ fix /reassemble /hope it works / get to work / think about how to fix it all day / eat, and do it all again would KILL me! Get one part perfect, and it will start to come together easier. I sure feel for you Bro. Hey a PUPPY will help you to feel better! (just messin w/ you)

[Shaka]

Zombie- No worries on the delayed reply!  I understand completely, really sucky situation!  I won't really get a chance to do any more work till Sunday anyways; just kinda brainstorming in the meantime.  I think I understand the pressure test.  I put a little soap down inside the manifold so I can hear it bubbling if there is a leak, right?  Will the soap cause any problems when I start the motor back up and it gets sucked through?  I would imagine as long as it is a small amount it should just pass right through.  Just thinking about the reeds, I don't really think there is a good seal there.  It is just a fiberglass/composite material that has slight ridges from the weave, having to make a seal against a piece of hard plastic.  I don't know how well of a seal it has to make, but seems like it would definitely leak somewhat.  A Viton coated seat just makes so much more sense!  Do you know the symptoms of leaky reeds?  Would that cause my loss of top end?  I sent an email to malossiusaonline inquiring the dimensions of the VL15 reed block.  Hopefully, they can get back to me with some useful information.  If that block fits that may well be my next step.  That thing is pricey though, $89!  I think a call to Steve at Moped Hospital is in order as well!

I like your idea about having an aluminum spacer cut with a water jet!  I may try to make one on my own first, a dremel is a great tool!  But, I will definitely look into it!  Glad to get another opinion on the squish zone as well, that has been in the back of my mind all along!  It's not the block-manifold space that is off.  It's the bottom half of the manifold-reed block-top half of manifold joint.  The side flanges on the reed block are not very wide!  It is cut in on the sides from where the bolt holes are kinda like an hour glass, but with a flat middle.  This is part of the reason why I think an entirely new reed block may work better. 

I would love to be able to put this project aside for awhile, I'm pretty burned out on it!  I just want to get it running right with the current setup so I can move on to the Vento.  Once I get that going I will have back up transportation and can focus back on the ZX! The Vento is going to take some money I fear though, something I'm tired of putting into scoots right now!  They are almost like boats, a big hole in water you throw money into!  I guess it's a little more justifiable though, I don't use a boat to get me to work!

p.s.- Still good on the puppy!