Noo!!!!... Toast? :( [Archive] - Provoscooter.com

burnt_toast

11-10-2005, 03:57 PM

My zip broke down two days ago as I was slowing down at a stopsign, and hasnt started since. :(

Today I put in a new plug with hopes that maybe the one in there was burnt up. Nothing. Then tried jumping from my car, still nothing. I finally did what has worked many times for the spree and sprayed starter fluid directly into the carb, in hope of maybe a sign of life.. And yet still nothing! :angry:

The two things I know to still check for are compression and spark, which I'll hopefully do tomorrow. But I'm fearing the worst.. Can the rings have worn out like this after only 3k miles?

Does anybody have any ideas to what could be wrong??? :confused:

Spyder John

11-10-2005, 04:01 PM

You'll know after the compression test -- hope it is an ignition problem, much easier and cheaper to fix. I'd go easy on the ether, it's heck on rings and cylinders, especially on a 2-stroke.

XPS1210

11-10-2005, 04:06 PM

NEVER use starter fluid on these things... real good way to destroy your cylinder....

compression, spark and fuel...

make sure it's getting gas... pull the fuel feed line off and see if gas comes out... the tank could be full but it could be clogged at the outlet of the tank...

but if you sprayed starter fluid in, it should have done something... so more likely a sparking issue.... as I doubt you could have zero compression... and you'd get some burning even with bad compression

speedy_scooter

11-10-2005, 04:50 PM

I'm guessing your coil is bad. I posted earlier that I had a buddy with a problem similar to yours. Maybe its a bad thing to have that 82cc Zip after all? j/k.

Spyder John

11-10-2005, 04:58 PM

make sure it's getting gas... pull the fuel feed line off and see if gas comes out... the tank could be full but it could be clogged at the outlet of the tank...

I think you'll have to pull a vacuum on the fuel valve to check unless you've replaced it with a manual one.

speedy_scooter

11-10-2005, 05:08 PM

Not with these Vento bikes. For some reason there is a vac line but no matter what you do the gas flows. I've taken the fuel valve apart before thinking that something was broken but it was all together and seemed to be right.

burnt_toast

11-10-2005, 08:38 PM

Oh yeh just to clear up, when I say I get nothing, I mean starter spins but no sign of engine starting up. And I checked for fuel out of the drain on the carb, and its fine.

I think its an ignition problem too, where and how much would it cost to replace a coil? would a local scooter shop carry one or is it a specific vento one?

It was really weird too, b/c when I burned up a cylinder before on the spree I was topping out down a hill in warm weather, which makes sense. But here I was just coasting up from a hill and it stalled and died at a stop. :confused:

str8dum

11-10-2005, 11:00 PM

There should be published specs for your coil. Use a multimeter and check the resistance. I'd guess they'd be similiar numbers tothat posted in the service manual for the Zuma. That or just chcicking for spark will tell you right away if it is the coil. I repalced the coil, stator, and voltage rectifier in my zuma all to find out that none of that is the problem (argh!). I'd really check all aspects before dropping the money on a coil.

You checked your reeds?

speedy_scooter

11-11-2005, 06:34 AM

Simple way to see if the coil works at all is to pull the plug, ground the plug to a good ground, and hit the electric starter. The plug should put out a nice purple/blue/white spark. If its not, well then, order up a new coil. From Vento they're $15 and you can always get a high output coil for around $30-50.

burnt_toast

11-11-2005, 06:48 AM

speedy_scooter

11-11-2005, 07:09 AM

You would need to find an online place. I sent you a PM about it.

burnt_toast

11-11-2005, 04:00 PM

Checked for spark, it was fine. A nice white bluish spark.

Next checked for compression by doing the thumb hole test, and it didn't pass.. it wouldn't pop my finger off the hole. :(

I pulled off the engine covers and bottom panel and will pull the cylinder next week to check the rings and internals of the cylinder. Pulled the head today and cylinder looked fine though..

Oh btw yes, it really is a 82cc cylinder I'll post pics in that thread.

burnt_toast

11-12-2005, 06:34 PM

Well unfortunately my initial guesses as to what the problem was were correct, in that for all practical purposes my piston is toast.. --o

Whats strange is that the cylinder walls don't feel scratched, but the piston is in terrible shape. Piston has deep gouges on multiple surface areas. Rings seem questionable, top one moves freely while bottom one is stuck. This explains my loss in compression and under the circumstances why it wouldnt even show a sign of life from the engine, even with starter fluid.

I believe the whole ordeal occured because I was messing with the idea of the intake. While using the smaller jets it may have been too lean and ruined the structural integrity of my piston. Even though its a mighty 82cc. :dunce:

Time for an upgrade. :ghost:

Can someone confirm that I have a 12mm wrist pin?

speedy_scooter

11-12-2005, 07:48 PM

Its sure looking like a 12mm to me. The 10's usually dont look as thick on the pin edges.

burnt_toast

11-12-2005, 08:35 PM

Its sure looking like a 12mm to me. The 10's usually dont look as thick on the pin edges.

yeh compared it to my spree pin and noticed that too, thx.

what size pin is your ported 50cc speedy?

speedy_scooter

11-13-2005, 06:48 AM

12mm.

speedy_scooter

11-13-2005, 03:34 PM

I just got to thinking again. (I know look out.lol) It looks as though your cylinder studs are longer than a regular Zip. I'm wondering if there is a difference and if indeed, I'm guessing that a cylinder designed for a normal Zip might not fit right. Are you able to measure the cylinder's height? I'll see what it is on my stock 50 and that will pretty much show us if there is a lenght difference in the studs.

XPS1210

11-13-2005, 04:38 PM

I think burnt toasts cylinder has been changed from the stock 49cc to a larger cylinder... the one in the picture I think is an aftermarket cylinder hence the longer studs...

Lennox

11-13-2005, 06:28 PM

I think burnt toasts cylinder has been changed from the stock 49cc to a larger cylinder... the one in the picture I think is an aftermarket cylinder hence the longer studs...

if the studs are longer, then so is the CRANK!

Burnt, you better be sure of what you have before trying to get parts for it!

burnt_toast

11-13-2005, 06:56 PM

if the studs are longer, then so is the CRANK!

Burnt, you better be sure of what you have before trying to get parts for it!

ahh crap, ur right. that would really suck. if crank was bigger.

Now I'm worried... :(

burnt_toast

11-13-2005, 08:21 PM

Now that I look at it it looks much longer than my spree cylinder!

;no

speedy plz let me know asap the lenghth of the 50cc zip cylinder.

just saw a pic of the 50cc crank..
http://www.myvento.net/kbarticles/images/70cc-0402.jpg

not looking good..

burnt_toast

11-13-2005, 08:48 PM

I just cross referenced the part numbers for the stud bolts..

not a match _o _-_-_- :mad: :angry: :eek: :( ;no

yup im royaly screwed now..

Spyder John

11-14-2005, 07:17 AM

If this 83cc is the 90 they get in Mexico then you aughta be able to get stock parts somehow. I don't suppose you could just go to the Vento Mexico site and pay with US funds and enter a US shipping address, but surely a call to Vento could get some answers. I know you're thinking "who wants stock," but hey, you're already at least 13cc ahead of the majority of us. BTW, I noticed that the Triton series in Mexico has something they're calling a 100cc. Man, if that has the same bottom end you do....

burnt_toast

11-14-2005, 08:50 AM

speedy_scooter

11-14-2005, 08:56 AM

Ok, just measured the height of the stock 50. Its 87mm high. I too checked some part #'s and the crank, cylinder, studs, piston, all that dont match up between the Mexican R3i and the US R3i. This really sucks. Try taking it to the shop you bought it from and see if they can get the parts. Another thing I just noticed, in you pic I see the carb is right near the cylinder. Had you just disconnected the carb or what because a US Zip doesnt have it mounted in the front like on a Triton, Jog, Zuma, Vino, and pretty much every other bike.

str8dum

11-14-2005, 09:06 AM

just buy an aftermarket crank and cylinder. Sure that will be cheaper than tracking down some low quality OEM parts. Or just get one of those stroker cylinders.

Spyder John

11-14-2005, 09:40 AM

JMO...
If it was me I wouldn't rule out the Mexican stuff without investigating completely. Sure they're not performance parts and there may be some hassle getting them unless you have friends SOB, but think about this: you've already got what amounts to a stroker crank (it would have to be if they can make a 100cc version). The exchange rate with the peso is way to our advantage. From what I can tell the 100cc cylinder is $470 MXN ($44 USD) and the piston is $100 MXN (<$10 USD). If you could get it tuned with the parts you already have, it has the potential for cheap performance. All I'm saying is that it's an avenue I would explore.

speedy_scooter

11-14-2005, 09:44 AM

burnt_toast

11-14-2005, 10:53 AM

Very good point Spyder. I think that a $54 cylinder and piston would be worth trying. Also, you can always get the stock cylinder ported out for better performance. Most likely you're going to need to find a performance 90cc ATV motor.

thats exactly what im looking at actually, will update if i find anything. ;)

i've contemplated finding a vento shop in mexico and phyically going over there, since I live in Texas and am not too far away. But I dont know if it would be ok to bring it back and all the hassle i would go through.

burnt_toast

11-14-2005, 12:08 PM

the vento avalanche atv has a 100cc motor w/ same size stud bolts and connecting rod, but a different pin.. so close.

florida derbi rocket

11-14-2005, 12:10 PM

Whats that Son..Your names Burnt_toast.?.....Hmm were gonna have to check out that motor a lil' closer..:army: :smokin: ....o-- ::handleba ..LOL!

florida derbi rocket

11-14-2005, 03:29 PM

I'm sorry to be Joking about your Cylinder problem...John

burnt_toast

11-14-2005, 03:30 PM

I just found a 99-105cc big bore kit that looks like it may fit my crank! Its for an atv, but looks very similar to my 90cc. If the pin is 12mm then I may have found a match!

I wont post the link (unless mods allow it), but heres a pic and info:

http://www.gokartsrus.com/crimages.php?imagefile=images/MB014472_zoom.jpg

This kit comes complete with piston, wrist pin, top bearing, clips, gaskets, hi-compression head, and cylinder. Direct bolt on with no modifications needed to achieve 99cc.

Part Number: MB014540 (modify to 99cc)

*note* To achieve the maximum 105cc this mod must be installed with the 45mm Crankshaft option otherwise your engine size will be at 99cc

How do I go on about measuring my crankshaft without taking it apart?

Maybe I can save a trip to mexico! :ll

burnt_toast

11-14-2005, 03:32 PM

I'm sorry to be Joking about your Cylinder problem...John

lol, its ok. I was joking about it too at first b/c it gave me an excuse to upgrade.. but unfortunatley SOMEONE had to tell me my crank was too big. :rolleyes: (jk speedy)

speedy_scooter

11-14-2005, 04:20 PM

Yo man, thats kinda pricey for that cylinder. $244.95 plus shipping?!?!:eek::eek:

burnt_toast

11-14-2005, 09:45 PM

did some more research on my magic 90cc, and heres what I got:

"Bore * stroke 52. 0mm * 43. 0mm "

just verified and my 90cc bore is 52mm, so that means my crank is 43mm correct?

str8dum

11-14-2005, 09:49 PM

normal crank is only like 39.2mm and bore of 42mm.

so that cylinder is 10mm wider and the crank is like 3 mm longer. Thats how you get 90cc.

You are only really concerned with the conrod length of your current crank. If it is a 43, then that cylinder will work.

3mm isnt that much to measure so i wouldnt be comfy measuring that accurately with the crank still in the case.

burnt_toast

11-15-2005, 11:11 AM

I'm still trying to figure out how the crank is supposed to be measured. Heres a picture of the conrod, can someone look at the pic and tell me which option is right? Or am I trying to measure the wrong thing?

thx

str8dum

11-15-2005, 11:23 AM

eye to eye i'm pretty sure

burnt_toast

11-15-2005, 11:34 AM

eye to eye i'm pretty sure

from center or from end points, option c or d on my drawing?

burnt_toast

11-15-2005, 02:18 PM

crank pics

speedy_scooter

11-15-2005, 03:32 PM

burnt_toast

11-15-2005, 03:52 PM

pics of 90cc skirt for reference.

Lennox

11-15-2005, 03:54 PM

I know you and I talked about it already but for everyone else, measure like in option C. Its from centerline to centerline. Also an easy way is to put the crank at BDC and mark where it is on a ruler, then put the crank at TDC and remeasure. The distance between TDC and BDC is your stroke.

center, to center...or as speedy puts it "measure the stroke"! Measuring the stroke is the easiest way if you don't plan on splitting the cases!?! Just make sure you are EXTREMELY accurate!

Lennox

11-15-2005, 04:16 PM

pics of 90cc skirt for reference.

I guess the cases are already big enough for the cylinder skirt?

Speedy, is your Zip case this open?

speedy_scooter

11-15-2005, 04:49 PM

Heh, unfortunatly mine isnt since I have a itsy bitsy 39.2mm stroke not a big 'ol 42 or 45mm(like some people out there);)

burnt_toast

11-15-2005, 05:49 PM

I guess the cases are already big enough for the cylinder skirt?

Speedy, is your Zip case this open?

I dont see why it wouldnt be since its a 90cc and not a 50cc crank case.

Lennox

11-16-2005, 04:20 PM

ok, now for the money question..................

what carb and jetting came with your bike toast??? When did all these problems with your motor start?

burnt_toast

11-17-2005, 06:32 AM

ok, now for the money question..................

what carb and jetting came with your bike toast??? When did all these problems with your motor start?

Here's the weird part, stock zip carb and size 70 jetting! :eek:

*edit* just compared carbs between mexican and american versions, and the overall assembly is different, but both use size 70 jets. does this mean my carb might actually be bigger too??

problems date back to when i put on my stage1, if you go through the tuning forum you could see most of them, lol.

I had no problems with the cylinder itself, until I tried making that intake out of rubber hosing and trying out sizes 77.5-85 jets. About a week after this is when it crapped out.

Lennox

11-17-2005, 03:28 PM

until I tried making that intake out of rubber hosing and trying out sizes 77.5-85 jets. About a week after this is when it crapped out.

your carb is most likely bigger...... can you measure it?

my guess is you created an air leak with this "New" intake.

burnt_toast

11-17-2005, 10:41 PM

your carb is most likely bigger...... can you measure it?

my guess is you created an air leak with this "New" intake.

how do I go on about measuring it? The intake diameter is 1.5", but I know that doesnt tell how big the carb is.

And yeh its possible I created a leak only adding to the already lean mixture caused by the open filter.

VINOGT

11-18-2005, 11:32 AM

Simply adding the open filter leans the mix enough to fry a cylinder.

*A J*

burnt_toast

11-18-2005, 01:28 PM

Simply adding the open filter leans the mix enough to fry a cylinder.

*A J*

sadly I found this out the hard way.. :(

alloo

11-20-2005, 04:09 AM

I would just take the bike into Premier Motorcycle Service on Broadway outside of Loop 410, the shop is actually at the end of Boardwalk before Bitter Rd. End all of your problems. Bob can help you.

burnt_toast

11-20-2005, 07:22 AM

I would just take the bike into Premier Motorcycle Service on Broadway outside of Loop 410, the shop is actually at the end of Boardwalk before Bitter Rd. End all of your problems. Bob can help you.

isnt that a dirtbike shop? I think I've seen it before and been there if it is.

And BTW, Lets just say I got some tricks up my sleeve... :naught: ;wink)

*edit* hey just checked ur profile, you are in San Antonio, you wana meet up sometime once I get my zip going?

Spyder John

11-20-2005, 09:27 AM

Some tricks up your sleeve, eh? Did you find a 100cc P&C that'll work? Or decide to go ahead and open the case? Inquiring minds want to know!

speedy_scooter

11-20-2005, 10:30 AM

hehehehe, I feel special that I know.:D I'll keep it a secret until we find out how it works!!

alloo

11-20-2005, 05:09 PM

Nope the guy used to be the head mechanic at KCI. He does excellent work. Yes, we can meet up. I usually ride with the guys from the Alamo Scoots on yahoo groups. We're supposed to get together on Friday for a ride. I would check Premiere out. Hey you just want to get your bike running then move on buddy.

burnt_toast

11-20-2005, 10:48 PM

sounds good alloo. thx for keepin it quiet speedy. :)

Not to worry I will update with info and pics as soon as I know its a go. ;)

str8dum

11-21-2005, 06:16 AM

Hopefully its not another half baked scheme that will set you back even further
:yippy: Just kidding and good luck!

Lennox

11-21-2005, 08:48 AM

Hopefully its not another half baked scheme that will set you back even further
:yippy: Just kidding and good luck!

is Cambles chunky soup, or Progresso/

Spyder John

11-21-2005, 09:12 AM

Hey now I kinda liked the can-take. Sort of a Junkyard Wars/ Mad max look::unk:: . May have even worked had the wide-open unifilter not already toasted the engine. :smokin:

burnt_toast

11-21-2005, 09:24 AM

Hey now I kinda liked the can-take. Sort of a Junkyard Wars/ Mad max look::unk:: . May have even worked had the wide-open unifilter not already toasted the engine. :smokin:

:werd: it did work! the idea worked quite well actually, almost no lag between throttle but SOMEone had to shoot that idea down.. and look what happened! --o lol

burnt_toast

11-23-2005, 04:09 PM

heres some more pics of what happened to the piston. Notice its not only fried and scratched, but disfigured too! some crazy stuff happened in there.. :eek:

Spyder John

11-23-2005, 04:19 PM

Woah, check out that ring groove. Notice though that its consistant with the axis of the wrist pin. Any evidence of FOD?

burnt_toast

11-23-2005, 04:20 PM

the update u've been waiting for, lol:

http://www.provoscooter.com/vbull/showthread.php?t=4411

burnt_toast

12-14-2005, 11:52 PM

sigh..

XPS1210

12-15-2005, 12:36 AM

ouch! that's from a hot piston? My thoughts anyway... what did you determine?

Elliott

12-15-2005, 03:36 AM

It Looks Like The Spark Plug Did that Hole on Top . ;no

speedy_scooter

12-15-2005, 04:09 AM

burnt_toast

12-15-2005, 09:14 AM

It Looks Like The Spark Plug Did that Hole on Top . ;no

it makes sense, I remember tightening the plug a bit more than needed. Plus this piston was shaped more conical ontop to increase compression.

What would be the best way to clean the crankcase area of the leftover piston shavings? I've been using a small wet towel and my finger and managed to get some stuff out. Would it be safe to spray compressed air in there, or would it get into the oil line?

burnt_toast

12-15-2005, 09:20 AM

Wow, I havent seen a piston like that in a while. I'm guessing that you were running too hot of a plug and it just started to eat away at the piston slowly until boom! This 90cc motor doesnt seem to working so well for ya.

It was actually doing real great until the final ride, even then it gave me no sign of the problem. I was pulling on every car I could get a chance, it was so fun! :race:

Ahh crap, I just remembered when I tried putting the plug in the head alone while the engine was apart the node was almost level with the bottom of the head, so since this piston is bigger on top and I tighted the plug a bit too much second time around, theres the mistake. :angry:

str8dum

12-15-2005, 10:36 AM

U just burned up your NEW motor? Wow thats some bad luck. Hopefully parts are cheap. Good luck.

speedy_scooter

12-15-2005, 11:16 AM

Spyder John

12-15-2005, 12:41 PM

It was actually doing real great until the final ride, even then it gave me no sign of the problem. I was pulling on every car I could get a chance, it was so fun! :race:

Ahh crap, I just remembered when I tried putting the plug in the head alone while the engine was apart the node was almost level with the bottom of the head, so since this piston is bigger on top and I tighted the plug a bit too much second time around, theres the mistake. :angry:
Are you saying that the piston was actually hitting the plug? Too hot a plug makes sense, but I can tell you from experience that when a piston hits a spark plug the electrode bends and shorts out and you get no spark.

burnt_toast

12-15-2005, 12:57 PM

Are you saying that the piston was actually hitting the plug? Too hot a plug makes sense, but I can tell you from experience that when a piston hits a spark plug the electrode bends and shorts out and you get no spark.

i think it was an aluminum piston, so it was weaker material.

btw cool sig spyder john.

speedy_scooter

12-15-2005, 12:57 PM

When he ran this his plug was just sooo close to the piston that it would spark right next to it and the top of the piston got too hot causing it to kinda melt a bit and then it eventually just broke. I know what your saying though SJ about the electrode bending.

florida derbi rocket

12-15-2005, 01:11 PM

Hey, I just figured something out here. What plug were you using, the BR8HSA stock plug? If so thats definitly what caused it with the extended electrode. It looks liek you can get by with just a piston. As for the case flushing its gonna be a fair ammount of work. I'd say pull the motor from the frame. Then when you have it off fill the case with about 1/2cup of gas and slosh it around down in there. then tip the whole cases over and let the pieces fall out. do that a couple times and then look in to see if you see any sparkles of metal.Speedy got it again..:ll I looked up over the doorway of my workshop this morn and saw the NGK boxes and remembered how I have to have a shorter plug for my Derbi motor ..the Piaggio motor plug is real long. I'm sorry Burnt had to be an example..but hey all info is good ..sorry Burnt:( John

speedy_scooter

12-15-2005, 02:04 PM

Yea, with my Corsa/r it uses a 3/4" plug threads and the stock motor only uses the 1/2"plug threads. With BT's he just has an extended electrode not the actual thread length. It does suck though since his motor has so much potential!

burnt_toast

12-16-2005, 11:27 AM

Well speedy's observation was good, and ontop of that Dave explained to me that yet again, I was running lean.

When I broke in, I was still using the stock main jet since I figured it was 82cc stock anyway so it should be enough fuel for another 90cc. It broke in smoothly and felt good, but I should've noticed the extra coloring on my pipe, plus kept in mind the port work would require extra fuel. But I was oblivious to this and rode with the 70main and brh8sa plug. After break-in I checked my plug and it looked great, but in the process I was doing short burst runs and kept full throttle steady only a few times. Dave explained that at full throttle it required that extra fuel to keep it at a safe temp. So while my 70main was plenty for short distance neighborhood riding, it wasnt for long distance full throttle runs. And there you have it, a combination of wrong plug, lean at WOT, and disregard to that on my part..

This explains that mystery spyder john.

btw i think its kindy funny the 3 current posts in the tuning section are all problem I've had, lol. :o Atleast its a good review of what NOT to do when you upgrade.

Spyder John

12-16-2005, 06:55 PM

When you checked the plug did you run WOT for a while, chop the throttle and hit the kill switch, then coast to a stop? I guess the lesson here would be to remember that idle, mid-range, and WOT are three different circuits in the carb. I know you must be pretty bummed about this. We're all bummed for you, the setup had great potential. Do you know yet if you can just get by with a new piston?
BTW, I'm about to post in the Vento tuning section, so your posts won't be lonely for long.

burnt_toast

12-16-2005, 09:50 PM

thx for the company. :) My plug test was just a mix of everything so yeh not too accurate.

I'll see what I can do to remedy my situation, but gonna keep quite this time around. :---

str8dum

12-17-2005, 05:47 AM

Only a suggestion, but why not buy a bigger aftermarket carb this time and do it correctly? Something with readily available jets, as that seems to be what you have been lacking the past 2 motors.

burnt_toast

12-17-2005, 08:28 AM

Only a suggestion, but why not buy a bigger aftermarket carb this time and do it correctly? Something with readily available jets, as that seems to be what you have been lacking the past 2 motors.

thats the funny thing, I have the complete mikuni jet range from 77.5 to 95, plenty to play around with fuel settings. I just assumed I would only need them when using an open filter so they've been left unused. Once I upjet this time I will measure my carb and try to figure out what size it is.

str8dum

12-17-2005, 11:56 AM

yeah dont wanna burn up a 3 motor. Is the cylinder f'd as well or just the piston?

burnt_toast

12-17-2005, 04:04 PM

yeah dont wanna burn up a 3 motor. Is the cylinder f'd as well or just the piston?

time will tell. :dunce:

ex-racer#2

12-17-2005, 07:18 PM

It was actually doing real great until the final ride, even then it gave me no sign of the problem. I was pulling on every car I could get a chance, it was so fun! :race:

Ahh crap, I just remembered when I tried putting the plug in the head alone while the engine was apart the node was almost level with the bottom of the head, so since this piston is bigger on top and I tighted the plug a bit too much second time around, theres the mistake. :angry:

They always seem faster just before they go bang. Lean conditions make everything work really well and then the heat takes effect.