Is this just how 2 strokes are??

cslacker
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cslacker 8/13/2014 1:34pm
8/13/2014 1:34pm
I would charge my friends a case of beer, not $50 an hour. And a highly skilled person can easily do this job in under 5 hours.

The leak for the drain bolt will be easy to fix if it is due to stripped threads once the cases are split. No big deal.
mxrose3
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mxrose3 8/13/2014 1:37pm
8/13/2014 1:37pm Edited Date/Time 8/13/2014 1:41pm
Before you split the cases and do all that work, check one thing:
The star-detent wheel. The biggest complaint normally from owners of this bike are that it is hard to find neutral.
Some people have ground down the edges of the neutral position on the detent wheel to make it go into neutral easier.
If the previous owner did this and ground too much of those edges down, that could be a symptom. Also, make sure the bolt that holds it down is tight.
Read this (about 5 posts down):

Thumpertalk link
huck
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huck 8/13/2014 1:49pm
8/13/2014 1:49pm
I thought 2 strokes were indestructible?
cslacker
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cslacker 8/13/2014 2:00pm
8/13/2014 2:00pm
huck wrote:
I thought 2 strokes were indestructible?
Does a transmission care if the engine is a 2 or a 4 stroke?

The Shop

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mxrose3
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mxrose3 8/13/2014 2:07pm
8/13/2014 2:07pm
huck wrote:
I thought 2 strokes were indestructible?
huck
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huck 8/13/2014 2:08pm
8/13/2014 2:08pm
huck wrote:
I thought 2 strokes were indestructible?
mxrose3 wrote:
[img]https://upload.wikimedia.org/wikipedia/commons/7/77/Deepsea.JPG[/img]
Silly Whistling Silly
gt80rider
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gt80rider 8/13/2014 2:13pm
8/13/2014 2:13pm
Starting a yz125 cold- turn on choke, give zero throttle, kick, turn off choke immediately after firing up...

When hot... No choke, 1/4 throttle until it fires...
HazemG
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HazemG 8/13/2014 2:42pm
8/13/2014 2:42pm
mxrose3 wrote:
Before you split the cases and do all that work, check one thing: The star-detent wheel. The biggest complaint normally from owners of this bike are...
Before you split the cases and do all that work, check one thing:
The star-detent wheel. The biggest complaint normally from owners of this bike are that it is hard to find neutral.
Some people have ground down the edges of the neutral position on the detent wheel to make it go into neutral easier.
If the previous owner did this and ground too much of those edges down, that could be a symptom. Also, make sure the bolt that holds it down is tight.
Read this (about 5 posts down):

Thumpertalk link
Good focus.. will keep this in mind.. It might be time to cut my losses if that doesn't work. Not sure I want to rebuild the whole motor AND transmission. I wish I did my research on the 05-06 faulty part. Good on Yamaha not to recall the bike.. Angry
JBernard_401
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JBernard_401 8/13/2014 2:46pm
8/13/2014 2:46pm
huck wrote:
I thought 2 strokes were indestructible?
most likely due because he sadly doesnt have a red brake line and horrible graphics.
scotttydog 8/13/2014 2:50pm
8/13/2014 2:50pm
YZ125H1 wrote:
2 strokes should always start easy. My bike is 1 kick almost everytime hot or cold. What is your jetting and premix ratio? What type of...
2 strokes should always start easy. My bike is 1 kick almost everytime hot or cold. What is your jetting and premix ratio? What type of fuel are you running? Also color of plug?
Everything about Two strokes is easy except riding the dam things !
HazemG
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HazemG 8/13/2014 3:01pm
8/13/2014 3:01pm
YZ125H1 wrote:
2 strokes should always start easy. My bike is 1 kick almost everytime hot or cold. What is your jetting and premix ratio? What type of...
2 strokes should always start easy. My bike is 1 kick almost everytime hot or cold. What is your jetting and premix ratio? What type of fuel are you running? Also color of plug?
scotttydog wrote:
Everything about Two strokes is easy except riding the dam things !
At this point I wish it were true! I had always heard "the worst case scenario, it's 500 bucks tops" line about two strokes and apparently I was able to find the one exception!! Gggggreat! lol.
JA946
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JA946 8/13/2014 3:04pm
8/13/2014 3:04pm
YZ125H1 wrote:
2 strokes should always start easy. My bike is 1 kick almost everytime hot or cold. What is your jetting and premix ratio? What type of...
2 strokes should always start easy. My bike is 1 kick almost everytime hot or cold. What is your jetting and premix ratio? What type of fuel are you running? Also color of plug?
scotttydog wrote:
Everything about Two strokes is easy except riding the dam things !
HazemG wrote:
At this point I wish it were true! I had always heard "the worst case scenario, it's 500 bucks tops" line about two strokes and apparently...
At this point I wish it were true! I had always heard "the worst case scenario, it's 500 bucks tops" line about two strokes and apparently I was able to find the one exception!! Gggggreat! lol.
That gets thrown around by people with even the most basic mechanical understanding. Yes, it's only $500 in parts.
million
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million 8/13/2014 3:55pm
8/13/2014 3:55pm
Can’t help but feel you could perhaps be making more of this than it needs to be. I appreciate that the unknown is scary and the questions you’re asking suggest little experience with mechanics and the inner workings of motorbikes. I really don’t mean anything harsh by this. With that said, maybe its best you take this as an opportunity to learn and do the work yourself. If my 9 year old cousin can split a case with minimum supervision, then I’m sure you can too mate. It’s just really methodical work and nothing out of your ability. Take your time, get a manual, take pictures, be organised (separate part lots into boxes, trays, zip lock bags etc) and if you get stuck just fire some questions at us lot with some pics.

Starting procedure is unique to 2/4’s which has already been covered and any engine, or should I say every engine, will have something that needs attention eventually. Better the devil you know chap.
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rmpilot 8/13/2014 4:00pm
8/13/2014 4:00pm
hillbilly wrote:
You dont want a 2stroke to idel more than about 3 to 5 seconds. If you are not opening the throttle any and just kicking it...
You dont want a 2stroke to idel more than about 3 to 5 seconds.

If you are not opening the throttle any and just kicking it that is the problem.

Open the throttle half way and kick. It is not like a 4 stroke,it wont flood.
explain to me the idle part. what you are on the line or warming it up?
YZ125H1
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YZ125H1 8/13/2014 4:11pm
8/13/2014 4:11pm
hillbilly wrote:
You dont want a 2stroke to idel more than about 3 to 5 seconds. If you are not opening the throttle any and just kicking it...
You dont want a 2stroke to idel more than about 3 to 5 seconds.

If you are not opening the throttle any and just kicking it that is the problem.

Open the throttle half way and kick. It is not like a 4 stroke,it wont flood.
rmpilot wrote:
explain to me the idle part. what you are on the line or warming it up?
I think he is referring to a racing 125. Usually they are jetted for only high RPM and they almost never want to idle and will load up very quickly.
mx5471
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mx5471 8/13/2014 4:22pm
8/13/2014 4:22pm
This is just my opinion, but I do have considerable experience working on these things. I have an '06. You need to split the case. You said the shift stopper was broken off. That's a big piece, and it's still in there, either in big pieces or little ones. You don't want that tranny locking up when you are on the track. You could get hurt, or worse. The clutch basket gets the grooves from wear, not by that piece floating around. You need to split the case and look at everything. The tranny is pretty bulletproof. I suspect that you just need to get that stuff out and get a look at everything. There is a lock washer on the clutch side you need to get. There's 2 tabs on it but if some one took it out once, you can't use it again. It's #15 on the motosports OEM page for the clutch. You also need an o-ring for the case. It's #16 on the same page under crankcase. You also need a tube of Yamabond to seal the cases. $250 is too much, find another buddy. It's not very hard to split the case, but some have more ability than others. But, you need to split the case, clean it out, replace what you find wrong, clean the carb and start with stock jetting, and take it from there, and you will have a great bike to have a blast on.
Matt Fisher 8/13/2014 4:34pm
8/13/2014 4:34pm
hillbilly wrote:
You dont want a 2stroke to idel more than about 3 to 5 seconds. If you are not opening the throttle any and just kicking it...
You dont want a 2stroke to idel more than about 3 to 5 seconds.

If you are not opening the throttle any and just kicking it that is the problem.

Open the throttle half way and kick. It is not like a 4 stroke,it wont flood.
rmpilot wrote:
explain to me the idle part. what you are on the line or warming it up?
I'm going to disagree. My 2 strokes will idle just fine for several minutes and I do just that to warm them up- no cold seizing here. If the jetting is right, they'll idle just fine.

Years ago some 2 stroke carbs had no idle circuit, so the idea that they shouldn't idle came about. Why would you want the bike to die on something like a simple tip-over in a race? Makes no sense to me.



million
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million 8/13/2014 4:41pm
8/13/2014 4:41pm
hillbilly wrote:
You dont want a 2stroke to idel more than about 3 to 5 seconds. If you are not opening the throttle any and just kicking it...
You dont want a 2stroke to idel more than about 3 to 5 seconds.

If you are not opening the throttle any and just kicking it that is the problem.

Open the throttle half way and kick. It is not like a 4 stroke,it wont flood.
rmpilot wrote:
explain to me the idle part. what you are on the line or warming it up?
Matt Fisher wrote:
I'm going to disagree. My 2 strokes will idle just fine for several minutes and I do just that to warm them up- no cold seizing...
I'm going to disagree. My 2 strokes will idle just fine for several minutes and I do just that to warm them up- no cold seizing here. If the jetting is right, they'll idle just fine.

Years ago some 2 stroke carbs had no idle circuit, so the idea that they shouldn't idle came about. Why would you want the bike to die on something like a simple tip-over in a race? Makes no sense to me.



I'll bite. It's a safety thing thing also. Not every body or organization adhered to this but the clubs i raced at scrutinized the bikes and check for this. The theory was you didn't want to encourage a bike to run on in the even of a crash possibly catching or sucking in fingers, hands, loose jerseys or whatever

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Matt Fisher 8/13/2014 4:54pm
8/13/2014 4:54pm
rmpilot wrote:
explain to me the idle part. what you are on the line or warming it up?
Matt Fisher wrote:
I'm going to disagree. My 2 strokes will idle just fine for several minutes and I do just that to warm them up- no cold seizing...
I'm going to disagree. My 2 strokes will idle just fine for several minutes and I do just that to warm them up- no cold seizing here. If the jetting is right, they'll idle just fine.

Years ago some 2 stroke carbs had no idle circuit, so the idea that they shouldn't idle came about. Why would you want the bike to die on something like a simple tip-over in a race? Makes no sense to me.



million wrote:
I'll bite. It's a safety thing thing also. Not every body or organization adhered to this but the clubs i raced at scrutinized the bikes and...
I'll bite. It's a safety thing thing also. Not every body or organization adhered to this but the clubs i raced at scrutinized the bikes and check for this. The theory was you didn't want to encourage a bike to run on in the even of a crash possibly catching or sucking in fingers, hands, loose jerseys or whatever
So at your club all fuel injected bikes are outlawed, along with any newer bike (last 20 years) with an idle circuit that's properly jetted? Of course not. A bike in gear with the throttle stuck at 9000 rpm is a far cry from one that will idle on the stand in neutral or will idle for 20 seconds on it's side at 700 rpms.
million
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million 8/13/2014 5:03pm
8/13/2014 5:03pm
No need to the smart man. Them USED TO BE the rules sir. Read it again, i used words like "encourage a bike to free run".

A well jetted bike can have the idle turned down can't it? And yes your right the rules changed when 4st came about
me_da_racer
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me_da_racer 8/13/2014 6:11pm
8/13/2014 6:11pm
IWreckALot wrote:
When you're kicking the bike, are you giving it any gas at all? I was taught not to touch the throttle on a 4 stroke while...
When you're kicking the bike, are you giving it any gas at all? I was taught not to touch the throttle on a 4 stroke while kicking it (which I normally did anyways). But when I switched, I was told that 2 strokes like a little gas when you're kicking it. When I start mine, as I kick, I twist the throttle a quarter of a turn or so. The bike seems to love it. Not sure if that's right or wrong but it's worked for me.
HazemG wrote:
Not at all.. Like you, on my honda 450 I just kick it and within 1-2 kicks it fires right up, cold, warm whatever.. So have...
Not at all.. Like you, on my honda 450 I just kick it and within 1-2 kicks it fires right up, cold, warm whatever.. So have you tried not giving it gas on your 2stroke? Maybe that's what is going on.. I'll give that a shot and see if it helps...


And mxrose, I'm not touching the choke lever at all, cold, warm or otherwise
IWreckALot wrote:
I tried kicking it a few times without twisting the throttle with mixed results. It would fire sometimes and sometimes not. I'd say give that a...
I tried kicking it a few times without twisting the throttle with mixed results. It would fire sometimes and sometimes not. I'd say give that a shot and see how it does.

Given the way the previous owner is acting, I'd probably put in a good piston and rings as was suggested by someone else just to be safe. I know nothing about bottom ends except I've never had a problem with one.

And for a reference, I've been running a fuel mix of 50% 100LL (get it from a local semi-private airport) and 50% premium gas. Mix that with a 32:1 Bel Ray oil. Bike seems to love this mix. Getting the 100LL is a bit of a pain in the ass but I'm not going to change that for now.
Quick HIGHJACK

What is 100LL and what does it cost?
Moto75
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Moto75 8/13/2014 6:26pm
8/13/2014 6:26pm
Sounds like you were brought up in the modern 4 stroke era.

When 4 strokes came out, all of us old 2 stroke guys had a hard time adjusting to not giving the bike any throttle when kicking. Open the throttle a little as you kick, bike will be fine.
Radical
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Radical 8/13/2014 7:10pm
8/13/2014 7:10pm Edited Date/Time 8/13/2014 8:24pm
On my older bikes, the shift fork would get bent and cause shifting issues. Check that too before splitting the cases. But, if you have pieces of the stopper floating around they have to be removed or you're putting yourself in danger. Having a tranny lock up unexpectedly is dangerous. So I recommend splitting the cases. BTW: the parts for a top end should not be $350. Maybe $150 tops. I believe I paid somewhere around $120 for a kit that included everything from the local Yamaha shop. All Yamaha parts.
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JBernard_401 8/13/2014 7:28pm
8/13/2014 7:28pm Edited Date/Time 8/13/2014 7:31pm
me_da_racer wrote:
Quick HIGHJACK

What is 100LL and what does it cost?
100 octane low lead. aka av gas (aircraft).

about 6$ a gal depending on where you are.
edit: MOST fields will NOT sell to you (walking up with a jug vs them filling your cessna up) since 9/11. so goodluck.
hillbilly
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hillbilly 8/13/2014 7:32pm
8/13/2014 7:32pm
hillbilly wrote:
You dont want a 2stroke to idel more than about 3 to 5 seconds. If you are not opening the throttle any and just kicking it...
You dont want a 2stroke to idel more than about 3 to 5 seconds.

If you are not opening the throttle any and just kicking it that is the problem.

Open the throttle half way and kick. It is not like a 4 stroke,it wont flood.
rmpilot wrote:
explain to me the idle part. what you are on the line or warming it up?
I'm about out of battery,this will take a while.

If you set a 2str to idel,and they have always had a pilot jet ,no idea where you get a idle circut,but,if it idles it is a little lean to do so.

When charging into a corner or a long downhill and the throttle is closed the engine is turning a lot of rpm.

The idle way there is not enuff air/fuel mixture being pulled in to lubricate the crank and piston skirt.

My way,when the throttle is closed the pilot jet supplies fuel mixture because it is in front of the slide.

Battery is dead,be back later to tell more advantages
Matt Fisher 8/13/2014 9:29pm
8/13/2014 9:29pm
million wrote:
No need to the smart man. Them USED TO BE the rules sir. Read it again, i used words like "encourage a bike to free run"...
No need to the smart man. Them USED TO BE the rules sir. Read it again, i used words like "encourage a bike to free run".

A well jetted bike can have the idle turned down can't it? And yes your right the rules changed when 4st came about
Didn't mean to come across as a smart ass and I didn't glean from your post that your were referring to the pre four stroke era.
bvm111
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bvm111 8/13/2014 10:07pm
8/13/2014 10:07pm Edited Date/Time 8/13/2014 10:08pm
mx5471 wrote:
This is just my opinion, but I do have considerable experience working on these things. I have an '06. You need to split the case. You...
This is just my opinion, but I do have considerable experience working on these things. I have an '06. You need to split the case. You said the shift stopper was broken off. That's a big piece, and it's still in there, either in big pieces or little ones. You don't want that tranny locking up when you are on the track. You could get hurt, or worse. The clutch basket gets the grooves from wear, not by that piece floating around. You need to split the case and look at everything. The tranny is pretty bulletproof. I suspect that you just need to get that stuff out and get a look at everything. There is a lock washer on the clutch side you need to get. There's 2 tabs on it but if some one took it out once, you can't use it again. It's #15 on the motosports OEM page for the clutch. You also need an o-ring for the case. It's #16 on the same page under crankcase. You also need a tube of Yamabond to seal the cases. $250 is too much, find another buddy. It's not very hard to split the case, but some have more ability than others. But, you need to split the case, clean it out, replace what you find wrong, clean the carb and start with stock jetting, and take it from there, and you will have a great bike to have a blast on.
X2!!!

Order a service manual, not owners manual, and the parts MX recommended. I split my first cases when I was 13 by myself on my 87 CR80! If you can follow a typical service manual and have the mechanical ability of a chimp you can do this on your own, it's not as complex as you think.

I promise you will learn a ton about how it works and you won't be scared the next time something happens! Shit I think 75% of the fun of riding is understanding and working on my own motorcycle and making it run perfect!!!
pecu_83
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pecu_83 8/13/2014 10:38pm
8/13/2014 10:38pm
Where is the video of some pro testing a 250 2-stroke for the first time in a long time (maybe Nick Wey or js7 or it9?)? He could not get it fired up when warm and then he remembers its a 2-stroke and kicks it full throttle and fires right up. I thought it was hilarious Smile

My RM125 fires in 1-2 kicks cold with the choke on and 1st kick hot with throttle open.
scotttydog 8/13/2014 11:02pm
8/13/2014 11:02pm
YZ125H1 wrote:
2 strokes should always start easy. My bike is 1 kick almost everytime hot or cold. What is your jetting and premix ratio? What type of...
2 strokes should always start easy. My bike is 1 kick almost everytime hot or cold. What is your jetting and premix ratio? What type of fuel are you running? Also color of plug?
scotttydog wrote:
Everything about Two strokes is easy except riding the dam things !
HazemG wrote:
At this point I wish it were true! I had always heard "the worst case scenario, it's 500 bucks tops" line about two strokes and apparently...
At this point I wish it were true! I had always heard "the worst case scenario, it's 500 bucks tops" line about two strokes and apparently I was able to find the one exception!! Gggggreat! lol.
exceptions to the rule don't change the rule.
HazemG
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HazemG 8/14/2014 6:48am
8/14/2014 6:48am
Would it be a good idea to try to find a transmission or cases from a parted out bike and just swapping that on? Or do you run the risk of the same exact problem? How much is a new 2014/15 motor for a yz? Would it bolt on to an 05 chassis?

Trying to figure out the safest/best/most cost effective way to go about this...

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