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Posted by: dj250r
do the comp check i think 135 125 is good on that motor for stock
my sons bike runs a hi comp motor at close to 200
plus a ton of other mods also if you get an aftermarket fuel filter and replace the fuel line
Dwayne
Posted by: Raptorlegs
Air screw should be 1.5-2 turns. Roll the idle screw with air filter on until quad starts. I found sarter fluid or chain lube help the process.
Posted by: Raptorlegs
The one that was faily flush on mine was the air, the one sticking out was the idle. Using a different carb so this is by memory.
Posted by: Raptorlegs
Quote
Originally posted by: atvrme
its a yamaha just like eton atv's
Linhai
Posted by: Hawkdriver
My son rides a 90cc Sundiro - it's very very similiar to an Eton. I bought it two years ago off someone else, so I don't know where the original dealer is, but Eton went out of business anyway, so I doubt that would help.
I just moved from GA to AL and after the move, I went to ride with my son, and his ATV started very rough (coughing every 2d stroke and choking when I added gas). It finally improved after I let it run for a while, and we rode down the street. About a block later it just quit. I haven't been able to start it since, and it has been 4 weeks. I looked at all the normal things - gas, oil, spark plug, etc. My father-in-law looked at it as well and he thinks a valve may be stuck.
I have been trying to find someplace to take a look at the bike, but none of the dealers around here will touch it since it's not their brand (ie - Polaris, Honda, Kawasaki, etc). I need some advice - his ATV is just sitting there as the summer fades away!!
Posted by: Hawkdriver
The full model name is Sundiro XDZ90ST. The engine is an air cooled 2-stroke, 82cc displacement, bore x stroke is 50x42mm, a compression ratio of 6:1, and it has an automatic transmission.
The spark plug is sparking. When we pulled off the air filter box, it doesn't feel like there is any suction in the engine compartment - it didn't suck with a hand over the opening (where the air filter connects) when we tried to crank it. That is why my father-in-law thought a valve might be stuck. It's getting gas (we checked the fuel line). The engine turns over, but it won't cough to life. It has an electric start, but the battery died, and we've just being trying to crank it by using the kick start (which my son normally can do just fine).
It has one of those safety straps that allow you to kill the engine when you pull it. It connects by a rubber cap to the back. It's come loose before, but I checked that several times, and I'm pretty positive that isn't it either.
Posted by: Hawkdriver
Here's an update - the bottom line though, is I still haven't figured out the problem. First - thanks to you all for your input and help!
I spent the weekend camping with a friend from Tennessee who has been playing with motorcycles all his life. I took the Sundiro with me to see if he could figure it out. After changing the spark plug, taking apart the carb (it was very clean), checking the suction on the carb, checking the fuel flow, and a couple of other things, he concluded that the engine isn't getting any gas. It sparks, and it sucks, but for some reason fuel is getting into the chamber. The fuel filter and fuel line are clear, and yes - the fuel switch is on (we tried it both in the reserve and on positions). His hand wouldn't get wet when he held it over the carb and we tried to crank it, even with hitting the gas pretty heavily.
He speculates that it may be the reed valve (in fact, he cannot logically come up with anything else).
03Ozark - you suggested this as well. I'm not that familiar with these engines to fully understand what a reed valve is. Does anyone know how hard it might be to replace and how much one might cost?
Thanks for the help!
Posted by: Hawkdriver
I haven't tested the compression yet - I have to find someplace that will even look at it. So far, no one will look at the bike. It seems to have pretty decent compression.
However, I called Cow Town USA (reccomended earlier in this thread) and they say they have NEVER seen a broken reed and it's almost always a seal problem. They told me to get a compression test first (again - back to my problem that no one will take a look at the bike).
I think I may just order a new reed and replace it to see if that fixes it. If it's not a seal and it's ultimately a blown seal, how difficult could THAT be to fix?
Again - thanks to you all for suggestions!
Posted by: Hawkdriver
When holding my hand over the carb, it DOES suck, but my hand does not get wet. Where should I look for the bad seal and how will I know it is bad when I see it? Is this seal in the carb?
Posted by: Hawkdriver
Sad to say, still no luck. I haven't been able to get a compression test, but when I use the kick start, there is lots of back pressure, which I have been told, is indicative of good compression. I have a new theory, that it's not getting gas. The spark plug is sparking (and it gets wet) but I think the carb might be clogged internally somewhere. I took it out last weekend and looked it over - it's quite clean and was full of gas. However, I am thinking the gas isnt making it to the chamber. I intend to get some carb cleaner this week and soak the carb for a few hours. Thanks for asking! Having my sons 4-wheeler down for the past 2 months is really getting depressing!
Posted by: Hawkdriver
Sorry for not getting back sooner - I've been dodging Hurricanes the past two weeks.
I did not yet take apart the carb, but I bought the carb cleaner and wil try to do it this week.
Bandits3 - if you can find the number to place you called for those parts, I would appreciate it very much. I am not very confident that cleaning the carb will make much difference.
Thanks to you all for the help.
Posted by: Hawkdriver
I finally put the carb back together after cleaning it thoroughly (I let the carb cleaner soak for about 24 hours). No luck. I'm starting to think it is the compression. Frankly, I am just frustrated. I'm going back to calling every mechanic in town to see if anyone will take a look at it.
Posted by: Hawkdriver
I'm taking my sons 4wheeler in on Thursday to get the compression check done. I really hope that tells me something.
DocTurbo - thanks for the analysis - I now know what a compression test will do for me!!
Bandits3 - thanks for the info - I'll order this weekend if that looks like it will help. Bumping up to 93cc would be fine by me! Thanks!
Posted by: Hawkdriver
Compression test COMPLETE!! Finally - it was so simple, I feel stupid for not doing it sooner.
Anyway, it appears to have good compression. The first stroke is about 75psi, the second takes it up to around 100psi, and the 3d (and all additional) strokes takes it to 120psi. The range mentioned earlier by someone else was 85-120. So - good compression - back to the spark plug or fuel issue?
I changed the plug a while back (but it hasn't run since then) - I will get another spark plug. Could it be wiring?
Posted by: Hawkdriver
Major Update - today a friend came over and we made some major headway.
I changed the spark plug again, confirmed it was firing. Emptied all the gas and put fresh gas in the tank. Blew out the carbeurator with carb cleaner (we think we found a couple of blockages) thoroughly. Took off all the plastic, removed the carbeurator, took out the reed valve. Confirmed the reed valve was fine, and cleaned it with carb cleaner. Reinstalled the reed valve, re-installed the carb (after finding an o-ring that was missing for one of the connectors). Using jumper cables to the battery, we tried to start it electrically (it has an electric start that works fine). We double checked the compression with the electric start and it topped out at 110psi. Re-installed new spark plug.
Using ether, we got a few 'coughs' from the engine. We had exhaust coming out of the back (not much, since the engine never caught, but some). Switching to the fuel/gas mix, we would get coughs when adjusting the two screws on the bottom of the carb, we got some coughing from the engine. It sounded like it wanted to catch, but just didn't.
My NEW question is: what is the standard setting for these adjustment screws on the bottom of the carb - I'm assuming that all the other bikes (eton and others) have the same or similiar carb. How many turns from the bottom should each screw be?
Here's a webpage with some pictures from today's maintenance, including some closeups of the carb. Sundiro Maintenance
Posted by: Hawkdriver
Do you know which screw is which??
Posted by: Hawkdriver
We took it apart as far as we dared...we sprayed carb cleaner in every hole and orifice we could find and made sure it blew out somewhere. I'm pretty sure it's clear...but I guess anything is possible.
Posted by: Hawkdriver
I tried pouring gas in the spark plug hole, I've tried Ether in the carb, I have tried the carb adjustments mentioned. I still can't it to fire up. The engine coughs a little when I do these things, but my neighbor (who has lots of dirtbike two-stroke engine experience) and I are pretty sure its either:
- the carb settings
- the amount of spark the plug is generating
It seems like the engine is getting TOO much gas or not enough spark. The Sundiro has an electric choke. When trying to crank it electrically, it coughs a few times and then stops coughing as it gets more fuel in the chamber. The spark plug is quite wet.
Since all this started after carrying the 4 wheeler cross country while moving in a heavy rain showers all day, I'm wondering if the coil is slightly damaged to the point that the spark plug fires, but it's not hot enough.
The other possibility is that the plug gap is wrong. Does anyone know what the gap should be on a 90cc engine like this one?
Also, could the coil be damaged where it still gives a spark to the engine, but not enough of one?
Again - thanks to all of you for the suggestions...
Posted by: Hawkdriver
New progress!!!
I went by a shop here the sells Polaris ATVs (it's a lawn mower shop) and looked at their 90cc Polaris. I was checking out the carb settings (I felt like I was spying) and wound up talking with one of the maintenance / tech guys. After I described all my trouble shooting, he suggested the exhaust was probably clogged. He recommended opening it up or taking it off and trying that.
Well, I had to take off the muffler at the engine mount (it's all welded solid)- but it now fires up with Ether sprayed directly into the carb. It has coughs and fires up with gas sprayed directly into the carb. WHOOOHOOO!!! Progress.
Now - it seems that the remaining problem is my carb. I am thinking I need to soak it again. Thoughts?
Posted by: Hawkdriver
OKAY - another update and request for help - again.
A friend of my neighbor has looked at my sons ATV and concluded that the problem is the timing. It has fuel, compression, and spark - apparently just NOT in the right order.
Does anyone know the timing settings for a SUNDIRO 90cc 4wheeler? I assume the settings for an Eton or Polaris would work.
THANKS IN ADVANCE!!!
Posted by: Hawkdriver
Where is the stator - is it hard to get to? How will I know what it is when I see it?
Posted by: Hawkdriver
Well, I give up. After 5 1/2 months of working on my son's ATV, it hasn't cranked once since the problem developed. My frustration level is pegged out. Nothing has worked. I cut off the muffler and got it to cough pretty good but it wouldn't crank at all.
Fortunately the local Polaris dealer finally agreed to look at it. It's in the shop now. I'll let you all know what they tell me.
Thanks to everyone for their constructive help and suggestions.
Posted by: Hawkdriver
I finally got my kids Sundiro back from the shop - it's a Polaris shop, so it is limited in what it could do. However, their diagnosis is that the piston on the top end is "scored" and is leaking fluid and compression. The mechanic was certain that a new set of piston and rings would fix the problem, and possibly a new "top end".
This is all a bit beyond me, but as I recall, piston and rings aren't very expensive. What about a new top end? Any one have ideas on where I can find one and how much it might cost? Thanks again...
Posted by: Hawkdriver
I thought about the compression readings as well - the same mechanic told me a number of weeks ago that it should run with as little as 60-90psi compression (as you said as well). However, now he is saying that the 'scoring' on the piston is causing 'blowback' and it's blowing fuel/air back out of the carb instead of sucking it in. This is all a bit beyond me, since I've never gotten this far into any engine. However, he was pretty convinced that is the problem. They didn't charge me a dime to trouble shoot and didn't try to sell me any parts.
Still - I'm convinced the experience exists in this forum to diagnosis the problem for good. Is it possible to have good compression yet have blowback that would prevent the engine from starting?
Posted by: Hawkdriver
I forgot to add that the mechanic took off the reed block and looked at the piston as it would cycle and saw this 'scoring'. He is assuming there is similiar scoring on the cylinder wall that he couldn't see.
Posted by: Hawkdriver
Bandits3 - I would need whatever parts and services pages they have on replacing the piston and rings. You can email me at hawkdriver@hawkdriver.com - thanks in advance. How significant is this job? I am planning on digging into the engine this weekend to see if the cylinder has 'scoring' on it as well. I'll take whatever pictures I can and post a link here once I get to that point.
Posted by: Hawkdriver
Bandits3 - I re-read your earlier post about the WRH racing site for the new top end. I'm calling them tomorrow about the same setup. Do you have any reccomendations on this mod? Thanks.
Posted by: oldyeller
Perhaps the local dealer went out of business but E-ton is alive and well.I don't know much about your bike but isn't it a two stroke engine?Two strokes don't have valves.Is the spark plug sparking?Is it wet or dry?We need some more info to help out.
Posted by: oldyeller
Is the spark plug wet or dry?Just trying to figure out if its getting too much gas or not enough.Also do a compression test.Should be somewhere between 85 and 120 lbs.With the gas turned on if you put your hand over the carb and crank it your hand should get wet with fuel as your hand is now a big choke.If you open the throttle you should feel some suction on your hand.If I understand you right it still runs but runs poorly?
Posted by: oldyeller
If you follow the peice that the carb attaches to where it bolts to the engine block that is the reed block.Just a few bolts and it should all come right out.You may have a broken reed or something.It could also be low compression or a blown seal as well.Did you test the compression?
Posted by: oldyeller
You can do the compression test yourself.Just buy or borrow a gauge and screw it into the sparkplug hole and take a reading.The seals will be on the crankshaft.Did you try putting a little shot of gas into the carb and seeing if it would start?
Posted by: TeamSRacing
I'd be willing to bet you reeds are good as is your compression. I've seen two with the exact problem over the lasty month, crank seals! If you hold your hand over the carb and it won't suck or get your hand wet, you're not sucking air or gas through the carb. The seals are real easy to replace and cheap if you do it yourself.
Just remember, top end compression and bottom end vacume are two different issues, both of which are needed to make a 2 stroke run.
Posted by: WILDCARDSHOOTER
hawkdriver you sundiro is the exact same quad as the articat , predator,bombardier , kasea, e-ton . find a friendly dealer or tech and pic there brain . the company that makes these bikes for sundiro is nusun try a web serch for it . if all else fails try calling my dealer he sells sundiro . its called cow town usa inc. 573-885-6300 or try cowtownusainc.com
we have had no trouble with ours so good luck
Posted by: Doctorturbo
The FIRST thing you need to do is do a compression test. There is no way myself or anybody else can make a call on this without a compression test. Once we get the compression test over, we will know where to go from there.
Ex.- Bad compression...........going to be bad top end, crank seals or a bad reed valve. In any event, the engine is going to have to be torn apart and one or all of these things will need to be fixed.
Ex.- Good compression.........Put a new plug in the thing and give it a shot of ether. Does it start and run for a few seconds and then die? If so, this will be a fuel issue. Plugged jet, port or fuel filter or line. If not, it's more than likely a spark issue.
Not to give you more to check or do but, these little 2 strokes will plug the muffler if the fuel to oil ratio is not on the money. I've seen these things so plugged with oil and carbon that there is no way these things would start. You can test it with air pressure and volume.
It's kinda weird that a shop won't work on it for you???? Around here, a shop will diagnosis anything if they think they can do it, and gladdy accept your money!!!!! They might tell you that they can't fix it because of parts, but they will tell you what is wrong for a price.
Get back to us with that compression test and there will be people on this board that will fix you up, and have that thing running in no time!!!!
Posted by: Doctorturbo
Hawkdriver, I'm sorry we could not figure this out for you. I know your frustration; been there a few times myself. Sometimes you just have to throw in the towel and let someone new take over.
Do us all a favor and let us know what they found out so we can all learn.
Posted by: wannabe1
This is kinda basic, but make sure the choke is not stuck. I have read that those electric chokes were a problem and that some of the manufacturers have gone to a manual choke just this year.
Posted by: wannabe1
BigRic, this thread is a year old.
Posted by: 03Ozark
Hawkdriver - My son also rides a Sundiro, exactly like your sons. A friend of mine also has one. We've put some miles on 'em already, with no real problems so far. We've had to replace plugs once in each.
You've already tried everything that I can think of trying! MAYBe a reed valve is stuck. I would try the hand over the carb throat thing mentioned above to see if there is any suction on your hand.
Good luck, and keep us posted on what you find out.
Sorry I couldn't be of help, I ll mention it to my friend that also owns a Sundiro, and see what he says.
Oh yeah, I had a problem like that once. I forgot to turn the gas ON.The tether coming undone got us once too.
FYI - Your Sundiro is the exact same as a Predator, except for the plastic.
Posted by: 03Ozark
Boyesen makes aftermarket reeds. They show them as for the Predator 90, but it is the same motor. They are not expensive. I couldn't tell you how to change them though, sorry!
Posted by: 03Ozark
Any updates???
Posted by: 03Ozark
Yeah, thats depressing!80(
Keep us updated.
Posted by: newnick
My boys eton was doing similar stuff a while back. The rings were gone. You can just hone the cylinder and put new rings and gaskets, maybe a piston if its bad. I also removed the oil injection.
Posted by: newnick
I'm not sure but I think the timing may be fixed with little adjustability, or not adjustable. If you have spark it may not be stong enough. If you take the flywheel off you'll find the stator, thats whereyou will see if you can adjust the timing or not. You probly need to clean the stator real well with say contact cleaner, unscrew the screws that hold it down and make sure theres no corrosion on them or the mating surfaces. Clean the surfaces of the stator with sandpaper . Some preditor 90's have problems with stators going bad, if you ride through water I would suspect you might be having the same problem. Also you could have corroded contacts where two wires connect together.
Posted by: newnick
Its on the right side , where the fan is. You need a flywheel puller to get to it, or a steering wheel puller.
Posted by: newnick
In an earlier post you said you checked the compresion and got 120 lbs. My sons would still run when it was down to 70 lbs. If you in fact have 120, I would look elsewhere for the problem. How did they determine your cylinder was scored? Did they take it apart? If you do a top end you can bore your stock cylinder from 50mm to 52mm and use a wiseco piston and rings or a stock one from polaris. Good luck
Posted by: newnick
If your blowing fuel out of the carb, not sucking it in then your reeds are the problem.The reeds are suppose to close on the compession stroke. Sounds like you need to find someone to work on it that you trust. Or take the plunge like many here and do it yourself. Theres plenty of information on how to work on them if you look. All of the motors are basically the same, so find an shop manual and get after it.
Posted by: newnick
http://webzoom.freewebs.com/miniatvs/Viper%20Manual.pdf Here's a manual for a Eton Viper 90
Posted by: quadduck
Have you taken the carb apart to clean the jets?
Posted by: quadduck
When you cleaned out the carb did you take it all the way apart? It sounds like there is still something blocked.
Posted by: quadduck
Unfortunately it may be time to take to a shop.
Posted by: quadduck
Posted by: quadduck
Bummer
Posted by: quadduck
Did we ever figure out who actually makes the motor?
Posted by: bandits3
I have a Sundiro Ridge Runner 90. Probably the same engine. Had the same problem. It was compression. I ordered a new top end, problem solved. I could not get the parts thru a dealer, but I found a place that sells a higher displacement kit that included a cylinder, piston, and rings. If you still don't have it fixed I can find the number of the place for you. I will try to check back on this site in a few days.
Posted by: bandits3
Sorry it took me so long to get back to this. I got the new top end from WRH Racing. They have a web site. It is wrhracing.com. The phone number is 251-675-9906. I got a new cylinder, piston, rings, and gaskets from them for around $150.00, I don't remember the exact number. The kit they sell is a 93cc instead of the stock 83cc, but it fits right on. I have not had any trouble since doing the top end job. It is tight, but the cylinder will come out without taking the motor out of the frame. I will try to check back in a day or so if you have any more questions.
Posted by: bandits3
I still think you have a compression problem. I doubt the engine still has 120 lbs. of compression if it is a few years old and has had no motor work done to it. A burnt piston will cause blowby. The motor will run with low comrpession, usually caused by worn rings, it just won't run very good. I have a parts and service manual for this bike that will help you if you decide to do the work yourself. Earlier in this thread I posted where I bought the parts to repair my bike. If you want a copy of the pages you need for this repair, leave a post on how I can get ahold of you and I will get you a copy. I will check back in a day or so.
Posted by: bandits3
Hawkdriver, check your e-mail.
Posted by: Chevymudnut
my son has the same 4 wheeler and it's acting the same way but sometimes it will start and just run kinda bad at top end and won't idle but most the time it will not run or after i have ran it for a few mintues it will not restart any ideas out there?
Posted by: atvrme
man all u need is air , fuel, and spark. with good comp. wicth you have take the air filter off and spray so mixed gas and 2 stroke oil in the carb and try to start it if that works you need to check to needle an seat and the floot lto see if there stuck i dont think you have a wireing problem my 5 year old races a eton 90 and ive had it in peaces top to bottom if your carb is bad i have a good used carb and they are easy to change. well dude hope i helped take care
Posted by: atvrme
its a yamaha just like eton atv's
Posted by: freightrain
Try pouring a little gas into the spark plug hole. It should fire up. Your compression reading seems a little low. I think it should be closer to 130. If it doesn't start with the gas in the hole trick, you most likely need a new piston and rings.
Posted by: BigRic
You say these crankcase seals are easy to replace. Don't you have to pull the stator on one side to get to the seal, and then pull the CVT to get to the seal on the other side?
Posted by: elecguitarACDC
Hi, i am new here, but i have been searching for forums about Sundiro's. I have a Sundiro Sunray 90. It was ok. But after a few years it started to really shut down. It wouldnt start good. and Something was always wrong. Well i am saving up to get a new 4-wheeler. So i just wanted 2 know if any1 needed anyparts for their sundiro sunray 90. if you need anyparts, i will be glad to sell them 2 u. (at a reasonable price that is). I will be on almost everyday to come check. In my profile on this website, i have a AIM screen-name. if u need to contact me plez do. and if you dont i believe my email address is in there too. Thanx 4 lookin.
