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Discussion Starter #1
Okay, getting frustrated with this thing. I recently put in a new standard compression Wisco piston. After the rebuild I didn’t reset the tensioner and stretched the timing chain so new timing chain and made sure the valves were in spec. It started after that and ran it around for about 1/2 hour and didn’t want to start again. In the process I blew the first starter. Had the oem one and through that back on it started but not easily. Come back another day and started up easier but not great. Then adjusted tps to .64 volts as it was sitting at .61. Started up great after that and rode it around thinking the problem was solved. Today, started up great then ran it 15 minutes turned off and didn’t start. Grab the charger (I know, bad idea..) set it to 2amps and let it sit. Cranked but not easily. Cranked some more and it makes a backlash sound after it gets over the compression cycle and sounds really bad. It does this when the starter isn’t turning over fast enough from my experience. In that process fried the starter I suspect cause it’s not wanting to turn and I can hear the injector squirting fuel. Same symptoms as before when It blew and it just clicks. When it heats up do the valves changed that much? I’ve spent about 5 hours so far trying to get the shimming perfect with no luck. Thoughts?
 

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Okay, getting frustrated with this thing. I recently put in a new standard compression Wisco piston. After the rebuild I didn’t reset the tensioner and stretched the timing chain so new timing chain and made sure the valves were in spec. It started after that and ran it around for about 1/2 hour and didn’t want to start again. In the process I blew the first starter. Had the oem one and through that back on it started but not easily. Come back another day and started up easier but not great. Then adjusted tps to .64 volts as it was sitting at .61. Started up great after that and rode it around thinking the problem was solved. Today, started up great then ran it 15 minutes turned off and didn’t start. Grab the charger (I know, bad idea..) set it to 2amps and let it sit. Cranked but not easily. Cranked some more and it makes a backlash sound after it gets over the compression cycle and sounds really bad. It does this when the starter isn’t turning over fast enough from my experience. In that process fried the starter I suspect cause it’s not wanting to turn and I can hear the injector squirting fuel. Same symptoms as before when It blew and it just clicks. When it heats up do the valves changed that much? I’ve spent about 5 hours so far trying to get the shimming perfect with no luck. Thoughts?
Do a compression test...65~75 psi normal range with the decompression mechanism working...160~190 psi if the decompression mechanism not working...

Make sure the decompression spring is on the exhaust cam...
 

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Discussion Starter #3
Decompression spring is good forgot to mention that. Mechanism seems to be working best I can tell. Would piston ring end gap have a considerable effect on turning over hard? I did not measure that when installing new rings/piston. Could the tensioner be bad causing too much pressure?
 

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Decompression spring is good forgot to mention that. Mechanism seems to be working best I can tell. Would piston ring end gap have a considerable effect on turning over hard? I did not measure that when installing new rings/piston. Could the tensioner be bad causing too much pressure?
Yes the tensioner can be bad especially if you didn't replace it when you stretched the cam chain after your rebuild...!

Can you do a compression test...?

Yes the shims expand when hot...so you want to shim out to 0.14mm intake & 0.22mm exhaust...!

What is the valve clearance of both intakes & both exhaust...??

You double checked the valve timing...TDC mark on the stator then 29 pins between the ex cam line & int cam dot timing marks...? see pictures
 

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Discussion Starter #5
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Discussion Starter #6
My feeler gauge goes from .127mm to .152mm so the intakes are about that. The exhaust are both at .22mm.

I can’t do a compression test because my starter is bad right now.
Are you supposed to be able to turn the engine backwards? It is locking up when I try to do that and making gear noises. It is for sure 29 pins on the chain. Decompression mechanism is working pushing the pin on the cam to open the valves and detracting once I let go.
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28799
 

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Discussion Starter #8
So that .009 should be 9 thousandths of an inch, which multiples by 25.4 (metric conversion) you get the .229mm measurement below which is what the manual recommends, correct?
Wanted to clear up that I didn’t have a feeler gauge between .127 and .152mm so I had to shim as close as I could to .14mm. (I have a Craftsman gauge just really want to make sure I’m doing this right)

The second piston ring broke tonight when I was taking it off so I’m guessing it was too tight (I never filed this to the proper gap when installed initially). This is probably the cause of the hard starting if that gap was too tight??
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Discussion Starter #10
I think we are saying the same thing just in different ways. That .009" you circled is for the exhaust cam, so .22mm. Both exhaust cams are .22mm. The intake cam is right side .152mm and the left is .127mm. Yeah I have a set of nice calipers that I used to measure the shims.
 

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I think we are saying the same thing just in different ways. That .009" you circled is for the exhaust cam, so .22mm. Both exhaust cams are .22mm. The intake cam is right side .152mm and the left is .127mm. Yeah I have a set of nice calipers that I used to measure the shims.
Valve Clearance: between cam and valve lifter
Standard:
Exhaust 0.17 ∼ 0.22 mm (0.0067 ∼ 0.0087 in.)
Inlet 0.10 ∼ 0.15 mm (0.0039 ∼ 0.0059 in.)

Do a compression test...!!
 

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I think we are saying the same thing just in different ways. That .009" you circled is for the exhaust cam, so .22mm. Both exhaust cams are .22mm. The intake cam is right side .152mm and the left is .127mm. Yeah I have a set of nice calipers that I used to measure the shims.
Yea! the exhaust cams are good...What about the intake..?

Are they around 0.14mm (0059")..??
 

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Discussion Starter #13
Yes they are about .14mm (see pics above). I got the new rings on tonight and they are set at the top of the tolerance. Waiting on parts to rebuild the starter. Seems like it is rolling over a little easier but I guess we’ll see. If it doesn’t then I am out of ideas cause otherwise I hadn’t changed anything. Did buy a manual tensioner that’s coming too to see if that might help.
 

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Yes they are about .14mm (see pics above). I got the new rings on tonight and they are set at the top of the tolerance. Waiting on parts to rebuild the starter. Seems like it is rolling over a little easier but I guess we’ll see. If it doesn’t then I am out of ideas cause otherwise I hadn’t changed anything. Did buy a manual tensioner that’s coming too to see if that might help.
In your first quote you mentioned you installed a wiseco piston...! Did wiseco send instructions for setting the ring end gap measurement for the piston rings...?

Here's the wiseco ring end gap PDF in case you need it ... http://www.wiseco.com/PDFs/Manuals/RingEndGap.pdf

Recommended that you use a new head gasket (OEM preferred) & replace the M10 head bolts washers with new ones...part# 92200 see pic


It good your replacing the cam chain tensioner, manual is much better & more reliable then the stock auto tensioner...

The stock tensioner might be faulty causing excessive drag on the starter.

Also did you check the starter's limiter gear for any damage to the teeth...see example pic
 

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Discussion Starter #15
Yes so I set the rings on the high side of the tolerance in the manual and was about what Wiseco recommended. They are thicker rings for sure so that I would assume increase compression? Obviously they were more rigid than the oem counterpart which I think was original looking at them. The kit came with all new gaskets so those are good. I also broke the starter limiter gear when the first starter blew up and purchased a new one.
 

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Discussion Starter #16
Figured it out. It was the piston rings. It started right up and ran it about half hour and started right back up again. Glad it’s fixed until the next thing breaks!
 

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Discussion Starter #17
So my issue did not go away. I had broken a second starter for good after the magnets blew apart this weekend. This leaves really only one thing, and that is the valve clearance and the decompression mechanism. I had bump started it and put 110 octane (I believe it was detonating so increased the octane) and it ran better than it ever has before. The thing would lift tires off the ground in all gears. However, I got it back to the shop and tried to start and it would not. The next day tried to cold start and this is when the starter finally went dead. My thought is that the decompression pin has wore down enough to where at .22mm for the exhaust it is too wide of a gap for the mechanism to work properly. I then lowered to .20mm and will try that once the new OEM starter gets here. If that still doesn't work, I will try .17mm on that. Since the thing won't roll over properly, I can't do a compression test otherwise I would.
 

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So my issue did not go away. I had broken a second starter for good after the magnets blew apart this weekend. This leaves really only one thing, and that is the valve clearance and the decompression mechanism. I had bump started it and put 110 octane (I believe it was detonating so increased the octane) and it ran better than it ever has before. The thing would lift tires off the ground in all gears. However, I got it back to the shop and tried to start and it would not. The next day tried to cold start and this is when the starter finally went dead. My thought is that the decompression pin has wore down enough to where at .22mm for the exhaust it is too wide of a gap for the mechanism to work properly. I then lowered to .20mm and will try that once the new OEM starter gets here. If that still doesn't work, I will try .17mm on that. Since the thing won't roll over properly, I can't do a compression test otherwise I would.
It might be your one-way starter clutch on the crank not releasing keeping your starter engaged when the is motor running...
 

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Discussion Starter #19
It might be your one-way starter clutch on the crank not releasing keeping your starter engaged when the is motor running...
To clarify, the starter fails when I am trying to turn over. I did check the one way starter clutch and it is functioning properly (starter gear only catches one direction). I had changed that out when I first got the bike last year.
 

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Discussion Starter #20
I tightened the exhaust valve with the decompression cam to .20mm and that did the trick. Starts beautifully with the new oem starter too.
 
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