05 seems hard to start

Just got a 05 rmz450. Bike is really clean. I'm coming off a ktm 250sx, so I'm used to 1 kick starts.


My valve clearances are in spec, my timing is good, but I'm not sure about jetting.


I'm at 800ft, right now the main jet is 165, pilot is 42, fuel screw is 1.5 turns out. Didn't check needle or position.


It does seem lean, popping on decel, and seems a little lean at full throttle. The best way I've found to start it is choke on, pump throttle 3 times, slow kick 3 times, the it takes about 5 to six kicks. When hot, it takes about 3 to 4 kicks, no hot start needed.


Any tips or tricks on these 05's? Must do mods?


Pics of bike




I know the rmz450 forums aren't as busy, but no suggestions on baseline jetting?

Baseline just start with stock, which you may be at for the year. 

Double Check valve clearance and cam timing. The chain can come loose(that year has a crappy cam chain tensioner, switch to a manual when you get the chance), or wear enough to cause a cam timing issue.

it should be a 1-2 kick bike 

The valves are in spec? How about your air filter and carb? Both really clean? When my '05 started popping it needed a new top end! 

Not a ton of people still running carbed Zukes. There are a few, but not many, which is why you are not getting a ton of responses. Anyways... your jetting seems very close to optimal at your elevation. You could try bumping up the main one size to see if that helps at WOT. I would start by checking your float height though. Backfire on decel is common on carbed 4 strokes so I wouldn't worry too much about that unless it is REALLY bad. 

Typically hard starting means worn top end, out of spec valves, or a timing issue. 

It's starting easier now that temps are in the 70's. I am going to check float height. Thanks for the suggestions.

Just to update, I also had a hanging idle issue that when I let off the throttle, it would idle high until I released the clutch.

Went over my intake boot, checked for air leak, decided to rebuild the carb and put on an adjustable fuel screw.

That was it, I adjusted the fuel screw to 4 turns out, the idle went crazy high so I turned it down and all problems went away, 1 to 2 kick starts now hot or cold, no more backfiring. Going to order a pilot 1 size larger and call it good.

Just wanted to let anyone know in case they had a similar issue.

Be sure to make sure cam chain isn’t stretched as well, when mine stretched it would only run with 14 links instead of 15 between the cam dots. And invest in a manual tensioner. Put a paint dot on the sprocket and cam to be able to tell your cam sprocket doesn’t spin on the pressed on cam in the future as well. You’ve resolved your issue it looks like, but just wanted to throw out some extra tips.

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