Hard starting hot

8 replies to this topic

Posted August 04, 2005 - 04:31 PM


My buddys 04 wr is hard to start once it is hot. It seems to have to crank alot before it fires up. It runs great! very strong, it this a characteristic of the yamaha? thx, Dino

  • MathProf

Posted August 04, 2005 - 05:17 PM


Sounds like you are lean.

What are your jet sizes?


Posted August 04, 2005 - 07:12 PM


not sure about the jetting, stock i think, free mods, sea level.

  • toyota_mdt_tech

Posted August 04, 2005 - 08:27 PM


Mine also cransk a little extra (but not much) and when I hit the hot start lever, it lights right off everytime. Have his see if the hot start lever makes it light quicker. Noext thing would be to check valve clearances. Too little with heat will make it harder to start.

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  • jbrooks26

Posted August 04, 2005 - 10:26 PM


not sure about the jetting, stock i think, free mods, sea level.

If he has done all of the free mods then I would try jetting first. If he has opened up both ends, intake and exhaust then he will most likely be a little lean. Hope this helps.


  • clark4131

Posted August 05, 2005 - 07:13 AM


If he's stock and at sea level, he's lean. He'll probably need to bump his starter, pilot and main jet at least one size, maybe more. Do the starter jet first, see what happens and then move to the pilot and so on...SC

  • bg10459

Posted August 05, 2005 - 11:56 AM


I have a similar problem, all jetted with a JD kit, runs great. After changing from a 65 to 70 starter jet the cold starting with choke on was WAY better. However, I believe (and someone please correct me if I'm wrong) the starter jet affects only the choke circuit, so it would only improve starting with the choke on. As far as hot starting, try the pilot jet and also increasing your idle a bit (I have yet to do this, but it's my next step). The hot start should work, but it hasn't helped much for me so I'm going after the pilot and idle. I also agree with SC; if you're jetting is stock you'll have to increase the main too.

  • Matty05

Posted August 05, 2005 - 03:01 PM


tell him to use his hot start lever.


Posted August 05, 2005 - 04:13 PM


He has opened the exhast but not the airbox, I thought about the vavles being tight, but it is very low hours. I think I will have him use the lever, I bet that is the ticket!


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