06' 450F Hard to Start

[Scott Marks]

Just bought an 06' 450F, because the guy was having trouble kick starting.  Push it and it takes right off, but won't kick start.  He has has the head rebuilt with new valves & checked nearly all the electrical.  He thinks there is a problem with the wiring harness.  I am taking a simpler road, starting with the carb and checking all the basics and mainly cleaning to ensure there is no trash in the carb.  I took the Pro Circuit T-4 pipe off (which is for SALE at a resonable price) and put the stock pipe back on. Starting with all stock jetting, settings, and installing all new hot start components. Just wondered if anyone has any tricks or things to look for.

Thanks,
Scott

P.S. Make me an offer on the Pro-Circuit T-4 header & silencer

[FPMXer]

If it's hard to kick start the valves could be out of tolerance. I know that my fo-fiddy is a pain in the butt to start when the valves are super tight. The right intake will be tighter than the left intake due to it getting the blast of intake charge. I can start my bike without the hotstart unless it washes out in a turn. Make sure the air filter is clean also these thumpers like clean filters and clean oil. I'd make you an offer on the pipe but I don't like pro-circus or it's parts. I'm also trying to sell my thumper to pay some bills off if you know any one interested. But while the carb is apart remove all the jets in the bowl, main area and there is a jet in the intake tube from the air box. Blow out all the passages in the carb. Check the spark plug for a light tan color, if it's black then the valves need to be checked and or shimmed.

[Scott Marks]

Thanks for the feedback,  I put the carb back on and began kicking.  Nothing happened until I twisted the throttle a few times and then the big backfire.  Did this a couple more times so I decided to check the timing and valves. Exhaust are a nice .008 and I can't even get a .002 thru the intake. Should be a .005. 

[FPMXer]

Do you have the factory service manual to do the valve work? If not I can send it to you in a PDF file. But the exhaust should be in the area of .17-.22 and the intakes at .10-.15 on TDC with the timing mark aligned with the notches and the cam lobes facing to the outside of the head away from each other.

[Scott Marks]

Yes, I purchased a service manual.  I am at TDC with the cam lobes facing out. This is where I took the measurement I mentioned below.  FYI, when I took the buckets off the shim on the left side was marked 220 and the shim on the right side had a marking of 230. This would indicate the RT valve is tighter than the LT. Correct? Do you have any suggestions what shims I should get?

[FPMXer]

I would think they both should have been either 220 or 230. I will have to look at the stockers I took out. I got a hot cams shim kit off e-bay and use it. I have only had to shim it once so far. But I have since parked it after spec'ing everything out while I await it's sale. I will look at the shims I took out and see if they are different.

[Scott Marks]

That would be great!  I have a few smaller size shims on their way from the Kawi dealership.  Any idea why the intakes are tight and the exhaust are fine?  Is it common for the intakes to tighten up more than the exhaust after you re-work the valves? This is what happens when you buy 2nd hand, you often have to start from scratch. 

[FPMXer]

I just checked the stockers and they both start and end with 5 the middle number is worn off. I shimmed them both the same and haven't had to reshim them yet. The right intake runs cooler than the rest because the intake charge is blasted on that valve as it exit's the carb. If they get any worse then a valve seat cut is in order.

[don46]

I've had different shims from the factory, no worries, your only talking thousanths, and no manuf. process is that close. as far as your clearances, I think one of you is talking thousands and one mm.

[Scott Marks]

You are correct, we have mentioned both mm's & thousanths. The service manual lists both clearances as well. I was able to gain the past history on the bike and that helps a bunch. Chad Watts (Watts perfections) rebuilt the entire motor about 10 months ago. They broke a radiator and cooked it. He had all the info on his computer and provided me with the shim #'s for all (4) valves upon the competion of the engine rebuild. The guy I bought it from tore it down, put in a new piston, rings and had the head re-worked again. Now I am able to compare the shims from job #1 to job #2. (2) are .002, (1) is .004, & (1) is .006 different.  Easily changed by doing a valve job.  Sorry for being so long winded, I am trying to trust the work that has been done. I know I should go ahead and pull the head off and see for myself.  I feel like the valves seated in and tighted up after job #2 and that is why they are tight now. I am going to get the clearances correct and see if I can kick start it. Ride it a few hours and check them again. If they change again, then I will pull the head off. This bike also has the wrong spark plug in it. The correct plug has the electrode and ground protruding past the treads. If the spark is being delivered up in the treads, I can't think this will help in kick starting.

[FPMXer]

You can order the plugs off www.sparkplugs.com if your local shop don't carry the correct plugs. The wrong plug could cause damage to any motor.

[Scott Marks]

Just thought I would give you an update.  Set the valves and put in the correct spark plug, still the same.  I took the bike to the Kawi dealer and they have been working on it most of the week.  All electical components check out o.k. they even took the CDI off of another bike and nothing. Only backfires.  Kawi tech support says it's electrial and to check the timing with a timing light.  They can't get the timing light to work because they feel the spark output is to low.  Makes no sense to anyone especially given the stator, coil, CDI, and other components check o.k. Our next step is to take all the electrical components off a running bike and see if that makes any differnce.

I let you know!

[hughes]

Just bought an 06' 450F, because the guy was having trouble kick starting.  Push it and it takes right off, but won't kick start.  He has has the head rebuilt with new valves & checked nearly all the electrical.  He thinks there is a problem with the wiring harness.  I am taking a simpler road, starting with the carb and checking all the basics and mainly cleaning to ensure there is no trash in the carb.  I took the Pro Circuit T-4 pipe off (which is for SALE at a resonable price) and put the stock pipe back on. Starting with all stock jetting, settings, and installing all new hot start components. Just wondered if anyone has any tricks or things to look for.

Thanks,
Scott

P.S. Make me an offer on the Pro-Circuit T-4 header & silencer

Sounds odd to me that it will push start and run but won't kick start and run, hard to believe that's is an ignition problem. Hope they figure it for you.

[5dracing]

This is so off the wall but it happened to me. Check the pipe and see that it is not blocked up. I had a '76 YZ25 that I did some work on and the guy brought me a pipe and said he wanted it put on after the rebuild. Long story short, put it on and the bike would not kick start. If you pushed it it would try to run. I found a mouse nest in it. Burned that out and it worked fine.

[Scott Marks]

It runs great when you push start it. Does the same with the Pro-Circuit exhaust & the factory exhaust.  Sometimes it will kick start, but more times it won't. I am taking my buddies 450 to the dealership in the morning and they are swapping the electrical components. Tonight I am thinking the gear position sensor really needs to be looked at closely, given this is the only component that changes the ignition timing.

I will keep you posted.