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XR400 hard starting / no starting

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I have an easy kick over issue with and XR400 1997 model. Just had a quick look at some Youtube vids and some forums on the XR400 hard starting issues and on the vids people kicking are kicking them over as easy as this one. My XR 200 has massive amounts of compression but these thing are easy to kick over ........so much so that one could mistake it for low compression. I would have thoght the 400 would have twice as much compression during start up but it has twice as less. The trick is certainly in the procedure so it seems. Can anyone offer any assistance or advice and experience with how easy they kick over. I can push this over by hand. I have done the valve clearances and adjusted the decomp lever. Even with the kicker at tdc I would have thought it would have some decent resistance, and it has some but not very much. It appears to be a common thing. It won't start even with a new plug in it. 

 

It's almost like it has no compression.

 

Any thoughts?

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My XR4 has way less compression kicking it over than my Yamaha 500. The XR runs as well as the Yamaha. I believe that there is a built in compression release in the Honda.

 

So what is the deal with lack of starting of the Honda. Did the symptom just start. Is it a new bike for you? Is there spark? Is there a clean pilot jet in the carb. Fuel in the tank.

 

Try filling in the blanks please.

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My XR4 has way less compression kicking it over than my Yamaha 500. The XR runs as well as the Yamaha. I believe that there is a built in compression release in the Honda.

 

So what is the deal with lack of starting of the Honda. Did the symptom just start. Is it a new bike for you? Is there spark? Is there a clean pilot jet in the carb. Fuel in the tank.

 

Try filling in the blanks please.

 

It is a clients bike I have in the workshop at the moment. I am not familiar with the XR400. All good on the 200 though. It has been hard to start for a while now and slowly getting worse. I have replaced the choke plate with an XRs only plate. New and gapped plug. Correct long reach plug too. The carb has been completly cleaned. Jetting is 65 pilot and 165 main. plug. Has spark. Just seems to have no compression. The decomp has been adjusted to 8-5 mm at the lever at TDC and I can see there is clearance when I remove one of the head caps where the decomp is. 

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Join the club...

 

Yes it seems to be the way. I would have thought that a big pot like that would have a heap of compression but I can hand push it over. 

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I have 3 xr 400's a 96, 98 and 02 they all are one kick start cold ....this is after a year of having a really hard time getting them to start.. the only way is to push it though real slow a few times (Fast and you feel no compression) till you feel compression at TDC then go just past, full choke and kick it though hard. If I tip over or stall hot then it can be a bitch sometimes  but I have found that if I hold throttle full open and decompress in for five or six full kicks and then the above method without the choke and they will fire. hope this helps

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if you can...for real right.?...push it through by hand, then the decomp is engaged/not adjusted correctly....or...wait for it...the spark plug is missing?....J/K..., try taking the cable off of the decomp lever on the head and make sure it is all the way back, then find TDC with your hand, if you can then it's not the cable..start there and tell us what you find.

Edited by Coolerking

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Cheers thanks lads. I will do that tonight and let you all know. 

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What kind of intake and exhaust mods have been for it to be running that jetting?

I'm guessing you're at or near sea level?

If you put the bike on a stand, put it in 1st gear, can you rotate the rear wheel by hand easily thru the engines stroke?

I've had my xr400 suddenly present with low to seemingly no compression a few times over the years, always after traveling to the mountains, high elevation and having the bike set out in the freezing temps overnight. I figure it was from sticking rings, valve or auto decomp mechanism. Always corrected itself after being warmed up.

Then again, you have to look at its age. Its probably past time for a new top end. And not knowing the previous owners and how careful they were with maintenance, all it takes is someone changing a spark plug once and not cleaning out the plug well of debris before removing it and having crap fall down into the cylinder, or poor air filter oiling or sealing. Don't take much of that to ruin compression.

Given the info you've provided, I think I would just remove the cylinder and check it and the piston/rings.

Edited by Trailryder42

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Hey People.

 

I managaed to get it running. 

It apears that it is all in the Technique. It is always harder when it is someone else machine and you have to start from scratch. 

I will keep trying to start it in the mornings for the next wek or so to try to learn the best approach for this machine. 

 

Thanks to you all for you help. It all really does help as your ideas and experience make all the difference. It has in these circumstances. Thanks very much. 

 

Kind regards 

 

Geoff. 

 

Heres a vid of it running. 

 

  • Like 2

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I forgot to say, the xr needs to be kicked from TDC every time. Kicking from anywhere else in the stroke is most often a wasted effort.

With the stock carb, set the choke and don't touch the throttle. Alternately, now that it has the XRs Only choke plate, that mod responds well to wicking the throttle open at the bottom of your kick.

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Hey Trail. 

I was reading some posts on another forum and I came across your name or I put the two together. Your information is great. What is your handle on the other forum?

Thanks for your advice very helpful. 

Here is a note I wrote on my dirtbike engine rebuild facebook page. You guys might be able to correct some information here or add to it to make it better. 

 

Here is a link to our page if you are interested.

https://www.facebook.com/CleanRebuilds

 

Hey chaps.

 

As above if any one in interested. 

This is what we found based form advice and youtube posts. 

 

  1. Set bike on side stand. 
  2. Turn on fuel tap. 
  3. Turn on choke to full. 
  4. Keep kill switch turned off at this stage. 
  5. Stand the bike up and stand on the ground on the right side of bike and kick with right leg.
  6. DO NOT TWIST THE THROTTLE.
  7. Pull in decomp lever and kick bike over two times. 
  8. Turn the kill switch to the on position. 
  9. Pull in the Decomp lever and kick through at average speed for  5-6 times.
  10. Let the decomp lever go and kick through once or twice to find TDC.
  11. Go one click further and let the kick starter go to the top and then a BIG kick through. (I lifited up off the ground for this kick. Without leaping off the ground I would have been there for days. But I am short so I needed the extra elevation).
  12. Repeat the process and by the second kick it should be away. 
  13. Leave the choke on for a while until it's warm.  

Hard starting when bike has been dropped. 

 

  1. Kill switch to the off position. 
  2. Turn the fuel off.
  3. Pull in the Decomp lever and kick through about 10 - 20 times with the throttle wide open. This will open the exhaust valve and allow air into the system and dry out the fuel. Go back to the procedure above but you should not need to use any choke.

This is what appears to have worked today.  

 

X42.jpg

 

X43.jpg

 

X416.jpg

 

X5.jpg

 

X9.jpg

 

X10.jpg

 

X11.jpg

 

X14.jpg

 

X15.jpg

 

X16.jpg

Edited by GEOF

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I go by the same handle everywhere.

Its a good thing you replaced that choke plate. That cast stock plate is notorious for breaking and being ingested and trashing the engine.

Your procedures sound good, but I think you can shorten it some. Just turn the kill switch on same time as the choke, go straight to step 9.

  • Like 1

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How I start my xr4 is to sit on bike off stand. Put it on full choke and kick it once or twice. 

 

The stock plate is steel with an extra thin steel plate and a goofy spring to open it in case of backfire. Am thinking about taking the choke plate out this winter and making a new one using the stock shape. Probably putting hole in it similar to the xr only.

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