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-   -   Yamaha XT600E 3TB - cold starting problems (https://www.horizonsunlimited.com/hubb/yamaha-tech/yamaha-xt600e-3tb-cold-starting-93500)

bernek9000 22 Nov 2017 11:53

Quote:

Originally Posted by xtrock (Post 574195)
Why dont you charge the battery? Its normal that the bike can die after starting and then have to start again if it has been standing for some days, do you pull throttle when it starts or just waiting to see what happens?

I charged it already and after each use I put the trickle charger on it.

I just wait and and see sometimes I tried give it some gas to clear up and it started after 1-2 attempts. But it’s definitely not leave it for a week and start first time .... it needs 3-4 attemps (some firing some not) to have it started!

I don’t like this condition because these small batteries can run out of juice after a few failed attempts...

xtrock 22 Nov 2017 12:31

If your battery cant do more than 3 starts you need to replace! Here is best way to start:

1. Always turn petcock off, and best is to let bike idle till it stops and carb is empty.

2.When you start bike hold throttle a little and when it fire up keep holding throttle same position, you then hear when idle is good and it will run on the choke.

I have had bike standing for 6months and it fires up after seconds on the starter, but you need to help it a little and dont rely on the choke in the beginning. Turn the screw in not hard but just so you know its in, and then 2,5 turns out. I use a drill bits and mark it so its easy to know turns. I think maybe you chasing a ghost here...

Jens Eskildsen 22 Nov 2017 17:19

Pretty sure both needles is in the 3rd (middle) slot stock.

You can raise the neelde in the main carb (left) a notch, that will provide more fuel, even at idle, and it should start better when cold.
You can shim the needles aswell, with small washers, to raise the needle half a notch. Shims from airsoftguns work great for this, and they come in really small increments.

However, if the carb is clean, the "right" way would be to change the idlejet to one size larger.

But its really easy to just alter the height of the needle. I can do it in about 10min, without removing the carb. So its well worth a shot.

Btw, I've had great succes with the cheap chineese carb rebuild kits on ebay, they're pretty complete with jets, needles ect.

bernek9000 22 Nov 2017 19:43

Quote:

Originally Posted by Jens Eskildsen (Post 574222)
Pretty sure both needles is in the 3rd (middle) slot stock.

You can raise the neelde in the main carb (left) a notch, that will provide more fuel, even at idle, and it should start better when cold.
You can shim the needles aswell, with small washers, to raise the needle half a notch. Shims from airsoftguns work great for this, and they come in really small increments.

However, if the carb is clean, the "right" way would be to change the idlejet to one size larger.

But its really easy to just alter the height of the needle. I can do it in about 10min, without removing the carb. So its well worth a shot.

Btw, I've had great succes with the cheap chineese carb rebuild kits on ebay, they're pretty complete with jets, needles ect.

How is it possible to change the clip position without taking the carbs off the bike ? I have to look for a way :)

If I raise the needle I should set the pilot jet screw to 2.5 turns out ? (default).

If I turn the pilot screw open 4.5-5 turns the mixture is too rich and it bogs during acceleration from idle ... how is the needle going to help ? The mixture will be even richer ?

So you say that my hard starting is because of a lean condition ? I tested with the pilot screw 2 turns towards 4 turns out and starting is almost the same.

Please share with me how can I adjust needle clips without removing the carbs so I can give this a try too :)

Thanks !

bernek9000 22 Nov 2017 20:09

If these two screws are accessible with the tank removed I can do it also :D

https://s18.postimg.org/5ijlmznll/carb.jpg

Not sure have to check :)

jjrider 22 Nov 2017 20:55

It's a royal PITA to mess with that needle with the carbs still on the bike , You have to take the whole mechanism out to get to the needle and there is a spring under it ect...... good luck getting it back in while on the bike . I've done it but in more time than just removing the carbs.

For starting and choke use something that everyone overlooks is the tube for the choke goes down into a hole in the left carb bowl. There is a small hole for the fuel to flow into that spot from the bowl that gets plugged easily and is hard to get clear. When you have the carbs off take the bowl off and make sure all those little passages are clear. I go up one size pilot jet on my bikes for winter and turn the mixture screw out about 1 turn farther , we don't have adjustable needles so not much can be done there other than one thin washer that can be move above or below the clip.

Raising the needle won't do much for cold starting anyways , it's got very little to do with idle. Changing the needle to a thinner one would have more effect but that isn't an option on these bikes.

Turn your idle back up , having it lower only makes it harder for the motor to stay running once it is started for what little gain it has to help it start.

Also make sure your o-rings and the outer seal/cover is good on your choke knob , if those are worn or bad they'll leak air past and not suck fuel as it should and make the choke less effective.


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bernek9000 22 Nov 2017 22:26

Quote:

Originally Posted by jjrider (Post 574235)
It's a royal PITA to mess with that needle with the carbs still on the bike , You have to take the whole mechanism out to get to the needle and there is a spring under it ect...... good luck getting it back in while on the bike . I've done it but in more time than just removing the carbs.

For starting and choke use something that everyone overlooks is the tube for the choke goes down into a hole in the left carb bowl. There is a small hole for the fuel to flow into that spot from the bowl that gets plugged easily and is hard to get clear. When you have the carbs off take the bowl off and make sure all those little passages are clear. I go up one size pilot jet on my bikes for winter and turn the mixture screw out about 1 turn farther , we don't have adjustable needles so not much can be done there other than one thin washer that can be move above or below the clip.

Raising the needle won't do much for cold starting anyways , it's got very little to do with idle. Changing the needle to a thinner one would have more effect but that isn't an option on these bikes.

Turn your idle back up , having it lower only makes it harder for the motor to stay running once it is started for what little gain it has to help it start.

Also make sure your o-rings and the outer seal/cover is good on your choke knob , if those are worn or bad they'll leak air past and not suck fuel as it should and make the choke less effective.


.

Thanks for the tips ! I will set the idle speed back to normal then and check those o-rings and the outer seal ! The outer seal is quite worn from what I've seen when I'm pulling or pushing the choke.

From what I've been told so far I came to the conclusion that I have a lean condition at starting. I will order bigger pilot jets (not sure where to find them) and I will richen the mixture a little more.

So far it seems the right pilot jet and the choke is the correct fix for my situation and maybe a new battery ! (old one is 6 months old and has been taken care of but maybe its just giving up)

I think the choke can definitely act up since the bike felt rich after it starts and heats up. Where can I find the outer rubber casing of the choke and the o-rings to buy ?

Also I need to find the patience to take out the carbs take them inside the house and clean them really well ...

:clap:

jjrider 23 Nov 2017 01:54

I don't think you can get that choke cap on its own . The biggest would be if there is a lot of extra space around the shaft in the bore from it being worn out , will make it hard to seal up and have good control of fuel delivery . I have 2 different wideband meters that I put on bikes to be able to physically see what the a/f ratio is while running . Makes it much more easy to jet correctly and know what jetting corrections are needed.

For jets I've bought 1 or 2 of every size that was still available oem from Partzilla , but I no longer recommend bothering ordering from them , you'll either never see the order or it'll be backordered for 6 months , I gave up on them.

Jets R Us has Teikei jets FAQ Identify that jet

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bernek9000 23 Nov 2017 06:11

Quote:

Originally Posted by jjrider (Post 574247)
I don't think you can get that choke cap on its own . The biggest would be if there is a lot of extra space around the shaft in the bore from it being worn out , will make it hard to seal up and have good control of fuel delivery . I have 2 different wideband meters that I put on bikes to be able to physically see what the a/f ratio is while running . Makes it much more easy to jet correctly and know what jetting corrections are needed.

For jets I've bought 1 or 2 of every size that was still available oem from Partzilla , but I no longer recommend bothering ordering from them , you'll either never see the order or it'll be backordered for 6 months , I gave up on them.

Jets R Us has Teikei jets FAQ Identify that jet

.

The pilot jet has a small needle thingy that I have for blocking a passage I think. Not sure if the pictures are informative only on Jets R US.

I might considering buying a second hand carburettor that might be in better condition. I've seen dual carburettor kits from CR Keihin but they are really expensive ... and even after spending that chunk of money you have to tune them for your specific application.

Either way I have to make sure mine are really clean and all passage ways are clear !

Thanks for your help !

Bernek

Jens Eskildsen 23 Nov 2017 14:27

Oeh yeah, a blocked choke passageway in the bowl is a classic. Most people dont clean that one. You really need everything to be clean and in good working condition, before you can finetune the carb. Otherwise youre just fixing the symptoms, not the problems. :D

As with the fuel/co-screw: You just dont give it a setting. You need to adjust if for the strongest idle (not necessarily the highest) each time you play with the carb settings. So theres no saying "set it to 2,5 turn out, and you'll be fine"

In general, it needs to be somewhere between 1,5-2,5 turns out, but you have some wiggleroom in each direction.

jjrider 24 Nov 2017 03:02

Quote:

Originally Posted by bernek9000 (Post 574256)
The pilot jet has a small needle thingy that I have for blocking a passage I think. Not sure if the pictures are informative only on Jets R US.

I might considering buying a second hand carburettor that might be in better condition. I've seen dual carburettor kits from CR Keihin but they are really expensive ... and even after spending that chunk of money you have to tune them for your specific application.

Either way I have to make sure mine are really clean and all passage ways are clear !

Thanks for your help !

Bernek

Under the jet pictures on Jets R Us you can click on the one below the dimensions and is blue , it'll take you to a separate page for ordering the different sizes they have available . The stock carbs do work pretty good , when tuned good,every passageway clean, and all seals doing their job .The ones on my hi-comp motor are working great, it's been dead reliable starter since I built it 3 years ago , just can't ride in any mist, drizzle or rain, heck even wet roads that create water mist from the tires and the left one freezes up the tiny air passage feeding the pilot jet and choke , she backfires and shuts down till thawed , unless I hold it at high rpms to run off the main jet . Stock motors don't run into that though .

The couple alternative carb option will improve performance and tune-ability ,however there is one huge drawback to them ,,, almost impossible to hook up the airbox ,unless you don't mind cobbling and crappy sealing intake runners or willing to run pod filters that really are only good for nice sunny dry days and preferably no offroading where junk from the rear tire can hammer them . For me no thanks .

There is however a new option that a guy from UK just made aware of and I have a set that I ran on my hybrid motor and that's the early '00's to '08? Kawasaki Ninja 250. Dual 32mm CVK's that slide right in the XT boots and fit pretty good. Once jetted right they are better than the stock ones and allow clean filtering . I will go that way with any XT I own rather than buying a set of replacement oem's . If you want to the 300Ninja EFI throttle bodies fit right in as well :innocent: But needs a Microsquirt injector controller and all the sensors added as well .




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bernek9000 24 Nov 2017 19:53

Quote:

Originally Posted by Jens Eskildsen (Post 574278)
Oeh yeah, a blocked choke passageway in the bowl is a classic. Most people dont clean that one. You really need everything to be clean and in good working condition, before you can finetune the carb. Otherwise youre just fixing the symptoms, not the problems. :D

As with the fuel/co-screw: You just dont give it a setting. You need to adjust if for the strongest idle (not necessarily the highest) each time you play with the carb settings. So theres no saying "set it to 2,5 turn out, and you'll be fine"

In general, it needs to be somewhere between 1,5-2,5 turns out, but you have some wiggleroom in each direction.

The choke passageway is in the detachable bowl part ? I will try to clean and I don't want to miss this important one.

Thanks !

http://www.horizonsunlimited.com/hub...ammer_oben.jpg

Can I use a thin steel wire to try cleaning it ?

bernek9000 26 Nov 2017 15:34

Hard starting could be valve also out of spec .. but I just changed them 1000 km ago when engine was rebuilt and I've checked them again 500 km ago so it can't be ...

P.S. can anyone confirm my picture above for the choke passageway ?

jjrider 26 Nov 2017 15:48

You can use whatever you want to get it cleaned out , the true size of the hole isn't important , just that it is open so the choke can suck up fuel , though I think that is how they control the amount of fuel the choke adds so if the hole is drilled bigger the choke will add more fuel when pulled.

As long as your checking the valve clearances correct and they're within sec they shouldn't be an issue.


.

Jens Eskildsen 26 Nov 2017 19:26

Yeb, thats the choke passageway.
I tossed my bowl in a ultrasonic cleaner, and sprayed brake cleaner through it afterwards. This was for my Dt125r, but simular setup.


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