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87trx250x not starting

739 views 3 replies 2 participants last post by  Here 2 help 
#1 ·
Hi I’m new to this forum and would appriciate any help I recently bought the 87 trx 250x (I also have another 87fourtrax250 and love it) this is one of my favorite quads I cleaned out the carb the other day because it wouldn’t idle on start up even with adjusting the choke after giving it a good cleaning and putting everything back together it idle real high so I shut it off to adjust it (hard without burning my hand while it’s running) now it will not start I’ve cleaned it again since to make sure very thing is where it should be and have a new carb coming in the mail can anybody help or have had this problem my wife and son want me to be able to ride with them thank you for your time
 
#2 ·
If it idled high after cleaning and assembly, it usually indicates 1) it is more efficient than before cleaning 2) the throttle cable or idle stop screw needs adjusted. Sounds to me like you were trying to adjust the idle mixture screw which only needs to be adjusted to smooth the idle at the desired idle speed. Good luck with the cheap Chinese carb you ordered from Amazon or Ebay - it will fit, but it most likely will need to be jetted for proper operation.

Follow up on this thread and let us know how you progress. Be sure to check or install a new spark plug - you might be surprised at how many problems a new spark plug can solve.
 
#3 ·
Thanks for the input I actually order a genuine oem Honda Keihin carb wasn’t cheap but you pay for what you get so it won’t be in for another week or so I also bought a new plug and ignition wire installed both already it still is not turning firing I did a compression test yesterday as well and compression is about 85. So I’m guessing and hoping it’s just a carb problem I don’t understand what went wrong though I’ve cleaned carbs hundreds of times and never had this problem
 
#4 ·
85 on the compression is low - hold the throttle wide open and allow a minimum of 5 compression strokes - typical compression will be 120 to 150 - might need to adjust the valves - valves tend to tighten with use and can reach a point where they are slightly open dropping the compression. I just adjusted the valves on my Briggs and Stratton lawn mower engine to get it to start and it's only 2 years old.
 
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