HELP 450r dont want to start when warm/hot

[predatorgh7]

Can anyone help me??? I got an 06 450R and for some reason this past fall and since ive had it back together for about two weeks now if I stall it or sometimes just shut it off when its warm/hot during a race or behind my house or even for the start of a race it doens’t want to start back up sometimes I get lucky and it does but that rarely happens. I have no idea wat the problem could be or is :confused: :confused: . Someone told me it could be timing but I checked that and its fine, someone else said it could be the valves but they are where they should be but I let the valves go with out checking them or changing the shims cuz I didn’t know much about it back then and the intakes got really bad and wore down the valve seat a little but I got those fixed up and put new intake valves in and Iv checked the valves every week now if not every other and ive never had to adjust the exhaust one and I changed the intakes I would say around july somewhere in there and Ive haven’t had to adjust it much since then. So could It be something wrong with the head or could it have something to do with jetting or wat? When I first started it today I checked and saw that a puff of black smoke came out of the pipe when u first hit the throttle for a few min while it was first started. I know that means the jetting is off. It was off most of last year and I finally got I good over the fall but now I guess its not. I got an 165 main, 48 pilot, stock leak, hrc needle(3rd clip down), and a boyseen quickshot and I cant remember where I have the air screw at its around where boyseen recommended it. Motor wise I got an hmf slip on with the stock header (im going to get the hmf header for it soon), the hrc cdi adaptor harness, and over this winter I put in a 13.5 to 1 compression wiesco piston and a new stock cylinder, and Im putting in a new clutch this week and that’s about it motor wisr everything else is pretty much stock. It is an e start but the starter clutch is out of it right now so im using the kicker. I also found that the 2 grears behind the starter clutch were about 4 teeth off I don’t know how that happen but I was told that it had to do with why it wouldn’t start but there in the right spot now and its still not starting and that was when I put it together 2 weeks ago I found it was off.


If anyone can help I would REALLY REALLY APPRECIATE it THANK U……..:D :D

[yernkie]

A buddy of mine had the same problem, his was however on a Kawi 400. His issue was timing. When we installed the cam we had it off by 2 teeth. I know that a Kawi is a dual cam setup and a 450 is a unicam, but he had the exact problem...when cool it would fire right up, but when hot it would not.

Another thought...you might check the wiring to make sure that something isn't getting too hot, like the cdi.

[Moto92]

are you using the hot start?

[Scro]

Originally posted by Moto92
are you using the hot start?

If the kickstart was added, then he probably still has the carb that came with the e-start - which doesn't have a hotstart.

All the new 450r's are doing it. It's just the nature of the beast. Your best bet would be to buy a carb with a hotstart, and use the kicker. It will be an all around better cranking machine with the kicker anyway, compared to an e-start....unless you send 24 volts to the starter (but you didn't hear that from me):uhoh:

[predatorgh7]

Originally posted by Scro
If the kickstart was added, then he probably still has the carb that came with the e-start - which doesn't have a hotstart.

All the new 450r's are doing it. It's just the nature of the beast. Your best bet would be to buy a carb with a hotstart, and use the kicker. It will be an all around better cranking machine with the kicker anyway, compared to an e-start....unless you send 24 volts to the starter (but you didn't hear that from me):uhoh:

I got it around xmas of last year. I add the kicker in April to it and it started fine even with out a hot start no matter how warm it was or how it shut off with the kicker but the estart took a sec for it to start but it still started (buts thats cuz the estart is a pain and sucks). But It didnt start acting up till about sept or so. I dont know how it would of all the sudden changed though. the only thing that happened was the valves going bad and the estart like I said in the first post. me and my dad are both lost about this and I cant really afford to take it any where.

It also is back kicking alot it did it in the fall to but not as much as it is now.....