Hard starting... tight valves?

RaceBikeRentals · May 7th, 2009, 12:45 PM

My racebike has 2400 miles on it and is getting harder and harder to start. Someone told me that if the valves are getting tighter, it will result in harder starting. Any feedback on this from you mech types?

Viper-Byte · May 7th, 2009, 02:39 PM

My bike takes a little extra cranking to start after a hard run in the high RPMs (no doubt where your bikes are run) Mine has 12000kms on it and is going for the 12000km service on Monday. I will see if I can get the valve specs before and after as a reference. Try taking it for a soft run for 10 mins (as if you were on the road) and see if that makes a difference.

randomwalk101 · May 7th, 2009, 04:55 PM

Go to town Richard

http://www.ninjette.org/forums/showthread.php?t=9924

TnNinjaGirl · May 7th, 2009, 05:11 PM

What do you mean by the valves getting "tight?" If by that you mean that the clearances are too small and the cam is resting on the valve and keeping it partially open all the time, you could possibly have starting problems due to low compression. In fact, I'd get that checked out right away before you possibly bend a valve or cut a hole in a piston.

A simple compression check may yield an answer. If it holds compression you should be ok, if not more than likely you have a "leaky" valve due to it being open even when it's supposed to be closed.

Just a thought.

HKr1 · May 7th, 2009, 06:25 PM

Also, the new valve train is suppose to be a bit better. The clearance should be more as it wears. The only way its gonna get tighter, is if the valve seats are screwing up(soft). Time for a clearance check, good piece of mind

TnNinjaGirl · May 7th, 2009, 06:28 PM

Richard, do you break in your bikes in any way before racing them?

RaceBikeRentals · May 8th, 2009, 10:07 AM

Quote:

Originally Posted by randomwalk101

Go to town Richard

http://www.ninjette.org/forums/showthread.php?t=9924

Haha not me. When I see the innards like that, I get skeered.

Time to bring in the big guns

RaceBikeRentals · May 8th, 2009, 10:09 AM

Quote:

Originally Posted by TnNinjaGirl

What do you mean by the valves getting "tight?" If by that you mean that the clearances are too small and the cam is resting on the valve and keeping it partially open all the time, you could possibly have starting problems due to low compression. In fact, I'd get that checked out right away before you possibly bend a valve or cut a hole in a piston.

A simple compression check may yield an answer. If it holds compression you should be ok, if not more than likely you have a "leaky" valve due to it being open even when it's supposed to be closed.

Just a thought.

That's great info, thank you. I'll be bringing in someone to start checking the fleet for clearances.

For break-in, I do 5 heat cycles, including (2) 20 mile sessions on the track not exceeding 8000 rpms. Then I change the oil and let em rip

TnNinjaGirl · May 8th, 2009, 12:30 PM

There are lots of theories on break in. Basically they need to heat cycle and get lots of oil changes. Sounds like you are doing a fine job there.

almost40 · May 10th, 2009, 07:35 AM

PLUGS PLUGS PLUGS what did the plugs look like?? Thats where I start when trying to figure out "whats wrong here". Might be way too rich and fouling the plugs???

May 7th, 2009, 12:45 PM	#1
RaceBikeRentals Pimpin Name: Richard Location: Ninja 250 Whorehouse Join Date: Nov 2008 Motorcycle(s): Bunch of em Posts: 973	Hard starting... tight valves? My racebike has 2400 miles on it and is getting harder and harder to start. Someone told me that if the valves are getting tighter, it will result in harder starting. Any feedback on this from you mech types? __________________________________________________ -Richard MotoList.com <<<List your stuff!

May 7th, 2009, 02:39 PM	#2
Viper-Byte ninjette.org sage Name: David Location: Wellington, New Zealand Join Date: Dec 2008 Motorcycle(s): 08 Ninja 250R in Green! (Sold) Now 2011 Triumph Daytona 675 SE Posts: 564	My bike takes a little extra cranking to start after a hard run in the high RPMs (no doubt where your bikes are run) Mine has 12000kms on it and is going for the 12000km service on Monday. I will see if I can get the valve specs before and after as a reference. Try taking it for a soft run for 10 mins (as if you were on the road) and see if that makes a difference. __________________________________________________ 2008 GREEN Kawasaki Ninja 250R. AreaP Quiet Core Carbon Fibre : 8000k HIDs : Dynojet Jet kit : Double Bubble Windscreen

May 10th, 2009, 07:35 AM	#10
almost40 ninjette.org Monkey Spank Name: Kevin Location: Illinois Join Date: Apr 2009 Motorcycle(s): 2008 250R Track-Bike Woodcraft clip-ons and rearsets FZ-6 track bike Posts: A lot.	PLUGS PLUGS PLUGS what did the plugs look like?? Thats where I start when trying to figure out "whats wrong here". Might be way too rich and fouling the plugs??? __________________________________________________ Black 250R Full Area P QC Dyno Jet Kit 100 main 41T Rear Sprocket

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May 7th, 2009, 04:55 PM	#3
randomwalk101 self wrencher Name: john Location: houston Join Date: Dec 2008 Motorcycle(s): 08 250r and 07 600r Posts: A lot.	Go to town Richard http://www.ninjette.org/forums/showthread.php?t=9924

May 7th, 2009, 05:11 PM	#4
TnNinjaGirl Ms. Personality Name: CB Location: Murvill, TN Join Date: Jan 2009 Motorcycle(s): Depends on the week you ask Posts: A lot.	What do you mean by the valves getting "tight?" If by that you mean that the clearances are too small and the cam is resting on the valve and keeping it partially open all the time, you could possibly have starting problems due to low compression. In fact, I'd get that checked out right away before you possibly bend a valve or cut a hole in a piston. A simple compression check may yield an answer. If it holds compression you should be ok, if not more than likely you have a "leaky" valve due to it being open even when it's supposed to be closed. Just a thought.

May 7th, 2009, 06:25 PM	#5
HKr1 IC2(SW) Name: Kerry Location: Pensacola Join Date: Nov 2008 Motorcycle(s): . Posts: A lot.	Also, the new valve train is suppose to be a bit better. The clearance should be more as it wears. The only way its gonna get tighter, is if the valve seats are screwing up(soft). Time for a clearance check, good piece of mind

May 7th, 2009, 06:28 PM	#6
TnNinjaGirl Ms. Personality Name: CB Location: Murvill, TN Join Date: Jan 2009 Motorcycle(s): Depends on the week you ask Posts: A lot.	Richard, do you break in your bikes in any way before racing them?

May 8th, 2009, 12:30 PM	#9
TnNinjaGirl Ms. Personality Name: CB Location: Murvill, TN Join Date: Jan 2009 Motorcycle(s): Depends on the week you ask Posts: A lot.	There are lots of theories on break in. Basically they need to heat cycle and get lots of oil changes. Sounds like you are doing a fine job there.