Hard starting, and some odds and ends...

[sickopsycho]

Got a couple questions for you guys. I've been taking my 2007 Ninja on some extended rides- and I notice that sometimes when I stop to stretch, the bike can occassionally be extremely hard to start. I smell fuel when I'm cranking it, and eventually it will fire up. Is this an indication of a stuck carb float? I'm not seeing any fuel leakage on the motor, nor smelling fuel before I try to crank it. I also just replaced the float needles about 200 miles ago.

Next question... refers to the clutch. I get some slippage in 1st and 2nd gears when I get on it. I notice that the clutch lever, when released, doesn't always return all of the way to the end point, I have to push it with my hands (I dont *have* to puch it forward with my fingers, I just do- it's only about a half inch or so, maybe less). This doesnt seem to effect the slippage, ie when I push it forward it doesnt all of the sudden "grab". I'm wondering if the new aftermarket springs that someone recommended would take care of this slippage problem? Also- when I have the bike in first- I notice at low rpms it actually begins grabbing. It tried to pull the bike a little bit. It also will cut out when I first start it and drop it right into first, it'll just die unless I give it some gas while I do it. This is, of course, with the clutch lever pulled- meaning it *should* be disengaged. If I rev the bike up a little- say above 2000 rpms- it stops trying to pull the bike. Is this normal?

Next question- how much can I expect to pay to have a shop replace a couple of valve stems? My rear tire valve stem has RTV sealant on it... and a leak. Both of the tires are new, so I doubt it's the tires. I will take some soapy water and confirm before I take it in, but I'm 90% sure its the valve stems. Obviously I'd save more than a few bucks by removing the wheels myself and taking them in- so I'll probably do that. I would change the stems myself, but don;t have a tire machine =(

Last question... what is involved in a typical motorcycle state inspection? I live in NC- I assume its mostly a safety inspection, but I dont want to get in there and get thrown a curveball. I used to be a NC state inspector for automobiles, so I know that all my lights have to work, horn, blinkers and so on. My rear tail light lens has a crack, but I sealed it with silicon so that water cannot get in. This would pass on a car, I hope the same holds true on a bike. Any thoughts?

Thanks guys- look forward to any and all responses! I love my Ninjette! My girlfriend is getting jealous ever since I got my permit and tags

[sickopsycho]

By the way- Once I get the bike started after it gives me trouble when it's hot... it runs fine. Usually I have been giving it somewhere between full and partial throttle while cranking it- then it will fire up and run fine. Just some clarification there...
More clarification- When I first got the bike I adjusted the valves myself. I set them to the loose end of the spec, as I know that as they wear, they get tighter. I have had experience with another motor that would be extremely hard to start when hot when the valves needed adjusting, but I just did mine about 200 miles ago. They shouldnt need it again??

[Z1R rider]

I'd guess you've got at least one carb flooding if you're smelling gas along with hard starting. If it's bad enough it can "hydraulic" the motor, causing damage. It must have a float needle not closing for some reason, out of adjustment, or dirt between the needle and seat maybe. If the petcock is working properly it will only leak the gas that's already in the line, if the petcock's not holding it can leak enough to hydraulic.

ps: could be an enrichiner (choke) hanging up or not adjusted right too, that will flood it with a no throttle atempted start

pss: had needle leak and petcock failure when parked once = crankcase filled with gas = must change oil and had an empty gas tank

[sickopsycho]

Originally Posted by Z1R rider

I'd guess you've got at least one carb flooding if you're smelling gas along with hard starting. If it's bad enough it can "hydraulic" the motor, causing damage. It must have a float needle not closing for some reason, out of adjustment, or dirt between the needle and seat maybe. If the petcock is working properly it will only leak the gas that's already in the line, if the petcock's not holding it can leak enough to hydraulic.

ps: could be an enrichiner (choke) hanging up or not adjusted right too, that will flood it with a no throttle atempted start

pss: had needle leak and petcock failure when parked once = crankcase filled with gas = must change oil and had an empty gas tank

I actually just changed my oil, and thought that it smelled of gas. I didn't lose any noticeable amount of gas from the tank, though. The oil had about 50 miles on it, but I had put in standard penzoil and wanted to put Rotella in instead. Whats going on? Stuck float? I just changed them. The choke is fine, I checked it. The petcock is also fine I have checked it multiple times. I am getting gas in my oil, and hard to start. Stuck float needle seems unlikely since I just rebuilt the carbs with new float needs. Help!?

[Triple Jim]

For gasoline to leak and flood the engine, the petcock and at least one float valve have to be leaking.

There's something causing your clutch cable/actuator/lever assembly to not move properly. My stock parts work fine. Stiffer clutch springs may put a band aid on the problem, but not fix it.

In the NC county I live in, we don't have emissions inspections, just safety inspections. The most I'd expect to happen is the inspector checking all the lights, horn, and other obvious stuff. Usually it's pretty casual. I have no idea if they do emissions inspections on motorcycles in Raleigh, but they might.

[sickopsycho]

Originally Posted by Triple Jim

For gasoline to leak and flood the engine, the petcock and at least one float valve have to be leaking.

There's something causing your clutch cable/actuator/lever assembly to not move properly. My stock parts work fine. Stiffer clutch springs may put a band aid on the problem, but not fix it.

In the NC county I live in, we don't have emissions inspections, just safety inspections. The most I'd expect to happen is the inspector checking all the lights, horn, and other obvious stuff. Usually it's pretty casual. I have no idea if they do emissions inspections on motorcycles in Raleigh, but they might.

So I need to pull the carbs apart *again* and see what's hanging up I guess. The petcock is fine, it does not move gas without a vacuum applied, I know this. It's odd that it's an intermittent problem, and only when hot. Hope that gives a clue. Regarding the clutch... Could be the cable needs lubing or adjustment. I don't think the actuator at the clutch is effected by the slack at the handle, I think the slippage is unrelated.

[sickopsycho]

Oops I double posted

[Motofool]

Originally Posted by sickopsycho

So I need to pull the carbs apart *again* and see what's hanging up I guess. The petcock is fine, it does not move gas without a vacuum applied, I know this. It's odd that it's an intermittent problem, and only when hot. Hope that gives a clue. Regarding the clutch... Could be the cable needs lubing or adjustment. I don't think the actuator at the clutch is effected by the slack at the handle, I think the slippage is unrelated.

Those valves can leak when new and /or the seat (aluminum hole in the body of the carb) is dirty or has some deposits around it.
If that is the case, try putting the bike on the central stand when you stop, rather than on the side stand.

When the engine is hot, the mix tends towards reach (hot air rushing in has less mass).
One float valve that leaks, increases the level in the bowl and makes mix even reacher.
That is why the engine takes no choke, but some open throttle (more air) during hot start up.

http://faq.ninja250.org/wiki/Lubing_the_cables

http://faq.ninja250.org/wiki/Adjusting_the_clutch_cable

Your clutch cable, cable's heads and lever's pivot may need some good lubrication.
When the lever is normally released, there should be a noticeable lack of tension between the lowest end of the cable and the lever-actuator of the clutch (lever next to the clutch case).

[rgx107]

Another remote possibility is that the valves are too tight, it should make the bike hard to start when hot. You can rule this out if you know the history of the bike and that valves have been adjusted.

[sickopsycho]

Originally Posted by Motofool

Those valves can leak when new and /or the seat (aluminum hole in the body of the carb) is dirty or has some deposits around it.
If that is the case, try putting the bike on the central stand when you stop, rather than on the side stand.

When the engine is hot, the mix tends towards reach (hot air rushing in has less mass).
One float valve that leaks, increases the level in the bowl and makes mix even reacher.
That is why the engine takes no choke, but some open throttle (more air) during hot start up.

http://faq.ninja250.org/wiki/Lubing_the_cables

http://faq.ninja250.org/wiki/Adjusting_the_clutch_cable

Your clutch cable, cable's heads and lever's pivot may need some good lubrication.
When the lever is normally released, there should be a noticeable lack of tension between the lowest end of the cable and the lever-actuator of the clutch (lever next to the clutch case).

I'll take a look at the links and try to get my cables lubed up tonight. Also, as I ride today I'll put it on the centerstand instead of the side stand. I assume this is so the bike isn't leaning and one carb is filling up more than the other?

Originally Posted by rgx107

Another remote possibility is that the valves are too tight, it should make the bike hard to start when hot. You can rule this out if you know the history of the bike and that valves have been adjusted.

Yeah, like I said I was the last one to do the valves- it was about 200 miles ago. There was 1 intake and 1 exhaust on each cylinder that needed adjustment, so they are all now set to the "looser" end of the specs.

[Triple Jim]

Originally Posted by rgx107

Another remote possibility is that the valves are too tight, it should make the bike hard to start when hot.

Most of the valves in my 250 were too tight when I got it. I was finicky to start when cold, and wanted to idle at either 500 rpm to 2,500 rpm. When it was hot, it acted fine, like it does now with the valves adjusted properly.

[jkv45]

Do you see any gas dripping from the overflow hoses? I'd drain the floatbowls and look for debris. Rust from the tank can get under the needle and not allow it to seat (close) fully.

A clean tank and a good inline filter would eliminate that possibility.

You can do a quick check on the float levels with a piece of clear tubing also. There are diagrams posted here somewhere if you want to go that route.

[Soris Moto]

For less than $50, for brand name K&L reproduction parts, you could yank the carbs and rebuild them. Its a very simple process. Juts be sure to clean up the brass seat really well with 0000 fine steel wool, maybe run a Q-tip with aluminum/mag polish down in there. Really get that seat to shine. Clean the rest of the carb & install the new parts.

Take that time to adjust your valves. It takes 15 minutes to do and is well-worth checking out. Stop by a local auto parts store and buy a set of feeler gagues if you dont have any. A great tool to have handy for just this reason.

What I say to my customers is, "Do you want to screw around with it? Or do you want to FIX it?"

http://www.ebay.com/itm/2-NEW-KAWASA...9Tx~Kn&vxp=mtr

[Triple Jim]

He did say twice that he adjusted the valves already.

[sh123469]

Anybody though about vapor lock?

Hot weather, engine, gas. Stop for a few minutes let the heat really warm up the carbs. Vapor lock until you clear it then it runs fine.

[Soris Moto]

In my experience vapor lock is a myth. A properly put together carburetor with a functional cylinder head will never, ever "vapor lock". The pistons are constantly sucking and pushing air along the path of travel. There is never any stagnent air or pressure issue that would prevent vacuum action from acting on the nozzle of the emulsion tube.

Tl;Dr it's the carbs

[Triple Jim]

Maybe you mean that vapor lock is unlikely in a gravity feed system like our 250s have. I experienced real vapor lock while driving a motor home. I had winter gasoline and was driving south into much warmer air. The heat from the engine would vaporize the high vapor pressure winter blend in the fuel line between the tank and its fuel pump, and the pump would stop pumping. Luckily there were two fuel tanks, and I could run on the rear tank, which had its fuel pump much farther from the engine heat.

If a motorcycle's fuel lines get so hot that the gasoline boils, I can imagine there could be a problem with fuel delivery. Admittedly, that's probably not what was happening in Andrew's bike.

[eulark]

Originally Posted by Triple Jim

In the NC county I live in, we don't have emissions inspections, just safety inspections. The most I'd expect to happen is the inspector checking all the lights, horn, and other obvious stuff. Usually it's pretty casual. I have no idea if they do emissions inspections on motorcycles in Raleigh, but they might.

As far as I know, no county in NC has ever checked motorcycle emissions. Every mechanic I've asked scoffed when I asked about emissions testing haha.

[Triple Jim]

Good to know, thanks.