Hot start seized shut, '08 450


4 replies to this topic
  • ipsullivan

Posted August 09, 2014 - 05:24 AM

#1

I Realized my hot start was not functioning properly. So after some investigation I found the plunger is seized inside the carb. I detached the cable to get a better look and it has been sitting with PB blaster. Reattached the cable to try and wiggle it loose but still no luck.

Any thoughts on getting it out? I plan on replacing the the whole assembly so I don't mind breaking it. Just trying to avoiding breaking the plunger in half and still be stuck in the carb. Where the cable attaches seems flimsy.

Thanks for any help.

  • grayracer513

Posted August 10, 2014 - 09:03 AM

#2

Stuck hot start plungers can be a major PITA.  Start with a good long soak in PB Blaster.  Remove the top of the carb and look for a drilled passage in the back of that chamber.  That leads into the hot start bore, so some 'Blaster down that will help.

 

Then, use a hair dryer or heat gun to warm the carb up.  If you're lucky, you'll be able to use a screwdriver to twist the plunger loose.  Last time I encountered one, this worked, and I happened to have an old screwdriver that had the tip of the blade bent over into a short hook.  I was able to use that to pull the plunger out after I got it to rotate.

 

In an extreme case, you may have to drill a small hole in the plunger, tap threads into it (like #6 screw size, coarse thread).  Then you can take a long screw, run a nut onto it, drop a washer on it, and screw it into the plunger.  The nut and washer can then be used like a puller to draw it out.

 

Avoid this happening in the first place by running the bike after each wash and operating the hot start several times while the engine is running to pull out any water the might get in there.



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  • ipsullivan

Posted August 10, 2014 - 03:33 PM

#3

Just pulled the carb, looks like I am going to have to resort to drilling and tapping the plunger. Doesn't want to budge, both tabs that hold the cable broke off.

I might try grinding down screwdriver to fit the contour better. There is not a whole lot to bite on.

The joy of buying a used bike.

  • Wiz636

Posted August 12, 2014 - 10:35 AM

#4

Whenever I have my bike apart I pull the hot start plunger and put a very slight coating of grease on it to keep it from binding.



  • ipsullivan

Posted August 13, 2014 - 03:04 PM

#5

Got it out today. Ending up drilling and tapping it (#8-32) on a bridgeport and using the quill to pull it out.

Anyone with the same situation I would recommend using #6-32 if drilling by hand. The plunger broke in half at the groove for the seal because the wall thickness was very small after tapping. If I drilled it this size by hand it probably not have turned out the same. Probably only had .005" to hit or miss.

Perks of working at a machine shop.

Edited by ipsullivan, August 13, 2014 - 03:05 PM.






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