hard starting (valves are fine)



41 replies to this topic
  • dirtbikefodder

Posted October 15, 2013 - 06:38 AM

#1

Hey ya'll-

 

Picked up a Yamaha450 used , runs great except the starting is a little finicky.  Sometimes it kicks over in a few kicks, other times it takes about 20 kicks+... I have other dirt bikes (honda and Husky 250s) that I can kick over in one kick, so I'm pretty sure it's not my technique unless there's something unique to the Yamahas.

 

I opened up the carb, cleaned that.  Installed new spark plug.  New Battery.  And Valves are all within spec.

 

Also installed blinkers and rear light / TechVapor speedo.  It has an electric start, and when I try that it will turn but never completely turn over.  Sometimes it just clicks. 

 

Soooo what's next??  Could a Stator be the cause of starting issues?  Is there any recommendations on a good stator for WR450?

 

Thanks

 



  • ubu

Posted October 15, 2013 - 06:59 AM

#2

What year? Is it stock or has it been uncorked?



  • dirtbikefodder

Posted October 15, 2013 - 07:04 AM

#3

What year? Is it stock or has it been uncorked?

 

2005 - uncorked, gray wire removed.. airbox opened up with twin air foam filter.

 

She runs strong and idles fine.  But for whatever reason she's the most difficult bike I've ever had to kick start.  And electric start never works though it's there.  But as soon as it turns over, never dies out or anything.  I thought initially it was spark plug, but got a brand new one and same symptoms.  Next was the Valves check, everything fine.

 

While it's an older bike, it was meticulously maintained, synthetic oil after every other ride / filter too.  Owner claimed never ridden more then 1,500 miles and all mostly on trails.

 

Got me stumped.. I figured there wasn't enough spark hence the tough starting, but new spark plug and new battery.  Not really sure what the Stator does, I thought it just recharges the battery but if it's a new battery that shouldn't be an issue?


Edited by dirtbikefodder, October 15, 2013 - 07:07 AM.


  • ubu

Posted October 15, 2013 - 07:16 AM

#4

Is it just cold starting or all the time?

 

on my 08 I always gave it a shot or 2 of fuel (twist grip so Acc Pump squirts) before kicking it cold and it fired 1st kick. This was a YZ though.

 

I have no idea on the electric starter stuff. Did you look in the WR forum?



  • dirtbikefodder

Posted October 15, 2013 - 07:21 AM

#5

It's difficult hot or cold.. I have a Husky TE250 and Honda CRF230 and I can kick start both first try every time.

 

No I guess I could check WR Forum, I searched but nothing came up that wasn't because of Valves or Spark plug.  Maybe a mod could move this thread but I also think this isn't a Yamaha only issue - it just happened to occur on my Yamaha , who knows.

 

Stator would be my last ditch attempt at solving the issue as I think I've checked pretty much everything else that isn't the bottom end.  But once it runs, I have no issues.

 

Appreciate the input, I'm guessing it's the Stator .. Just don't want to spend the extra money and time on it if it won't solve the problem!



  • 717 MOTORSPORTS

Posted October 15, 2013 - 08:36 AM

#6

I highly doubt that it's the stator. May be your technique. Are you sure that when kicking it over, you are not twisting the throttle...even a little bit. Try holding the front brake on while kicking. This eliminates natural twisting. Find top dead centre, then move past it just a touch. Allow the kicker to come back up, then give it a good solid kick. That is what works best on my ktm when its hot, and any older WR/YZ I have tried



  • slomojo

Posted October 15, 2013 - 08:50 AM

#7

Check compression,there is more to valves than clearance.



  • dirtbikefodder

Posted October 15, 2013 - 09:36 AM

#8

Check compression,there is more to valves than clearance.

 

Wouldn't that affect how the motor runs?

 

I don't know about my kicking technique.. I have kicked over my Husky and Honda for a couple years now with no issue.  First try most of the time.  I put the footstand down on left side, stand up on peg and leverage above and come down pretty good on it.

 

I did notice that when I moved the kick lever out, when I pulled it back then out to the side, it would kick over a little better but still felt very inconsistent vs how the bike runs and how my other bikes turn over without issue.  Maybe it's just a special technique for Yamaha - but the electric start turns but doesn't fully turn over, seems like the issues maybe related with the kicker?

 

717 - you mention - you pull the kicker out and push down with your hand then let the kicker come back up before kicking it down again?   I'll give that a try to see if it kicks over better.  Thanks for that tip, I never had to do that with the Honda or Husky.  But they are much newer models


Edited by dirtbikefodder, October 15, 2013 - 09:38 AM.


  • Krannie McKranface

Posted October 15, 2013 - 11:39 AM

#9

What does 'cleaned the carb' mean?  Unless you replaced the pilot jet, cleared the passage above it with monofiliment wire, replaced the fuel screw oring, adjusted the fuel screw, cleaned and tested the apump nozzle, and cleared the pilot air jet, it's not 'clean' yet. 

 

What does 'valves are in spec mean'?  Unless you do a leak down test, you have no idea if the valve are leaking or not. Clearance is only part of it.

 

The key is to get it started (push, pull) and get it nice and hot, and then properly adjust the fuel screw, so the pilot circuit will start working in the correct range.

 

It will never start easily until the pilot circuit is working correctly.

 

Then once that is done, you can start checking off the other issues.



  • dirtbikefodder

Posted October 15, 2013 - 11:55 AM

#10

Wouldn't all those things affect the actual motor when it's running too? 

 

When I get it going, it runs awesome.  Idles strong, never pops when decel, never stumbles on accel, engine never cuts out or trouble idling (which I thought is what a pilot jet is responsible for)... what do I know - Also the electric start doesn't work (keeps trying to turn over but never does) - so that's why I'm thinking it's maybe electrical or fuse grounded? 

 

What does the Stator do?  Why on Baja-Designs site that when you add their equipment an upgraded Stator is required.  I don't have an upgraded Stator but have the equipment in the BajaDesigns kit.. not the exact same, different brand.. but was wondering if a Stator could cause such issues


Edited by dirtbikefodder, October 15, 2013 - 12:11 PM.


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  • bikedude987

Posted October 15, 2013 - 12:20 PM

#11

If the estart doesn't work, maybe the battery is dead and kicking it doesn't generate enough for a spark?  



  • dirtbikefodder

Posted October 15, 2013 - 12:27 PM

#12

If the estart doesn't work, maybe the battery is dead and kicking it doesn't generate enough for a spark?  

 

Thanks but I just put a brand new battery and spark plug..

 

Can a drained Stator make it hard to start a dirt bike?

 

I may be kicking it wrong, I never had issues with my newer dirt bikes.  But I will try to do the technique of gradually pushing the kicker down until it stops, then letting the kicker float back up by itself so the compression is right, then give it a couple kicks. 

 

I can't find anything about what a stator does on a dirt bike-- EDIT - just did a search and it seems that the STATOR is related to the ignition system on some dirt bikes?


Edited by dirtbikefodder, October 15, 2013 - 12:51 PM.


  • adamek

Posted October 15, 2013 - 02:27 PM

#13

you must check step by step , not all at once. I was one time : wire pushed from off switch and sometimes touch to handlebar

/ neutral / but I think you have a problem with carburator or valves


Edited by adamek, October 15, 2013 - 02:39 PM.


  • Krannie McKranface

Posted October 15, 2013 - 04:57 PM

#14

Thanks but I just put a brand new battery and spark plug..

 

Can a drained Stator make it hard to start a dirt bike?

 

I may be kicking it wrong, I never had issues with my newer dirt bikes.  But I will try to do the technique of gradually pushing the kicker down until it stops, then letting the kicker float back up by itself so the compression is right, then give it a couple kicks. 

 

I can't find anything about what a stator does on a dirt bike-- EDIT - just did a search and it seems that the STATOR is related to the ignition system on some dirt bikes?

The stator is the AC and DC magneto for the electrical system. If it works hot/running, it works all the time.

 

Your issue is one of improper fuel/air at low rpms (starting) which is usually valves leaking or carb tuning.

 

Have you tried using some hot start, hot start and choke, no choke, hot start only, partial thorttle, etc to get it started?



  • dirtbikefodder

Posted October 16, 2013 - 05:21 AM

#15

Yep.  I'll take a look again this weekend.  I tried it all.  Sometimes when I start, I can sense it's barely going to turn over so I have to whiskey throttle it to turn over and start idling.  But when it idles, it idles strong without any choke/hot start or having to use the throttle (once it's turned over).  And runs great, even when I'm lugging the bike @ LOW RPMS.  Maybe I'm not letting it compress/decompress fully when I'm kicking it.  I've heard some models are really pickey about the kick lever being in the correct spot vs other models.

 

thanks


Edited by dirtbikefodder, October 16, 2013 - 05:26 AM.


  • GuyGraham

Posted October 16, 2013 - 09:11 AM

#16

 New Battery.  ..............It has an electric start, and when I try that it will turn but never completely turn over.  Sometimes it just clicks. 

 

 

Your battery maybe new but something is wrong

the clicking is the starter relay...which happens when the battery hasn't got enough grunt to turn the motor over.

 

The bike will not run without a battery..

 

What is the voltage of the battery?

A new battery should be at least 12.80V, but more like 12.90v



  • Krannie McKranface

Posted October 16, 2013 - 09:23 AM

#17

Oh, guess I should read your entire post.....

 

Clicking is battery/charging system.

 

As mentioned, you need to test it with engine off (12.5+) and running (13.25-147.0) across the terminals to verify a working charging system.

 

Also, there are several ground points on this bike, in the harness on the left side, behind the headlight,  and under the tank, including the battery, which all must be perfect to get good starting.



  • dirtbikefodder

Posted October 16, 2013 - 09:26 AM

#18

Your battery maybe new but something is wrong

the clicking is the starter relay...which happens when the battery hasn't got enough grunt to turn the motor over.

 

The bike will not run without a battery..

 

What is the voltage of the battery?

A new battery should be at least 12.80V, but more like 12.90v

 

Right.  This is what I don't understand, I was having the starting issues so bought a new 12v battery.  But got same symptoms.  Thats why I was thinking the Stator because when I try the electric start, it has a very weak churn to it.. and sometimes I get the clicking noise (even with new battery).  I noticed when I try the electric start, the lights fade off as if it's losing juice and won't completely turn over. 

 

Bike is off site, I will take another look this weekend.  Look for any wiring issues , grounded fuses, etc.  But I don't really know how this affects kick-starting issues too.

 

 

Appreciate the help/input and will let ya know if I figure it out.


Edited by dirtbikefodder, October 16, 2013 - 09:28 AM.


  • Krannie McKranface

Posted October 16, 2013 - 10:43 AM

#19

You say it kicks right over, so it's not the stator.



  • dirtbikefodder

Posted October 16, 2013 - 10:47 AM

#20

You say it kicks right over, so it's not the stator.

I never said it kicks right over, second sentence on my original post:

 

"Sometimes it kicks over in a few kicks, other times it takes about 20 kicks+.." 

 

Actually truthfully, that 'kicks over in a few kicks' is being generous.. after it's warmed up , it seems to be a little easier but only occasionally will it kick over sooner rather then later.

 

Thought I've reiterated several times it's one of the hardest bikes I've ever had to kick over.  I said my Husky and CRF I can kick over first try.. which is true.






 
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