Hesitation question

[mtnairlover]

Ok, so I'm gonna ask this question and would like some honest answers (opinions). Be nice, cuz I'm such a freaking newb and I won't ask questions anymore if you treat me poorly. I really wanna know things about my bike, so here goes.

I've got an '06 Kawi Z750S, fuel-injected sweetie. Yeah, I likey my bikey. Recently, two friends helped to replace my tank and pulse cover (we changed oil and filter as well). I had a slight mishap the next day with the fuel pump to gas line, but after a quick call and a visit from my friend, my bike was back up and running smooth.

My question is this. In the mornings, when I start her up, she hesitates ever so slightly. Since I'm the only one who rides the Zed, I might be the only one who notices this stuff, so bear with me. I've been riding in the mornings since February, so morning starts have been colder, but only now, the hesitation seems more pronounced. Also, the transition between gear changes is so much more smooth in the mornings as compared to afternoons (is it the cold, or warmth, or me?). Lastly, as I'm heading down 287 in the mornings (before the sun comes up), I've noticed that I'm twisting harder on the throttle cuz it seems as though the Zed is having some misgivings about going faster. There isn't this quick response like there used to be. So, making a short story long, is this something that may possibly have to do with oil, or fuel, or...?

The Zed has about 6200 miles on her and I will be taking her in for the 7500-mile maintenance check-up soon. I was thinking if I get some good opinions here, I will feel better about asking certain questions when I take her in for her check-up.

[Lurch]

Did you change oil brands/weight? Also the throttle issue could be that the cables got moved or pinched when you installed the new tank. The hesitation could be anything most likely it's just the choke engaging if it smooths out pretty quickly I wouldn't worry about it.

Lurch

[rybo]

One other thought would be that the throttle bodies are out of synch. This should be easily corrected in your 7500 mile service.

[mtnairlover]

hmmm...oil? That could be the thing. I did change the brand this time out. I found out from RYBO the difference between synthetics. Some synths are made as "energy conserving" types. I didn't get that kind this time around. Went from a cheap brand to Valvoline.

Could you tell me more about the weight thing? What's the diff with the 10/30's, 10/40's, 5/30's, etc.? My ex used to put (a very long time ago) 20/50 (or, some such heavy weight) in my chevy cavalier (when it got higher in mileage) during the summer months.

We'll check on the throttle thing next time around too.

[rybo]

Oil is always a fun topic.

Multi Viscosity oil (what we use in the bikes) is rated at two temperatures. 0 degreed F and 200 degrees F. In the case of 10W40 the oil would be a 10 weight at 0 and a 40 weight at 200. There are additives in the oil that cause it to thicken as it heats up. This is beneficial because it provides better protection to your engine when you start is cold (it's thin then and flows better) and good protection when hot (thicker oil provides better protection to the moving parts once it's flowing well).

The additive that's used to make this happen is usually a polymer strand that coils up when cold and spreads out when warm. When it spreads out (like a long hair) the surface tension of the oil around it causes the oil to bind together better and behave like a much thicker oil. Now...you've heard the oil commercials where they talk about "viscosity breakdown". It's not really the oil that fails in this case, but the polymer strands in the oil. If you have, say, a 10 W 30 oil, the actual oil is 10 weight. The polymer strands cause it to behave like a 30 weight when warm. If the polymer strands break down, then the oil changes viscosity less, and therefore becomes more like a 10W 20 and eventually a 10W10. Make sense?

The greater the range between the numbers the more strands are in the oil. This increases the chances of breakdown. For example- 5W40 oil would have to increase thickness by 8X where 10W40 only increases by 4X....less polymer strands = less chance of breakdown and in the summer 10W is plenty thin enough as the oil will likely never see 0 degrees F

OK....To much text from me. Hope that's as clear as used motor oil

Scott

[Fly boy]

Scott, Your one to talk to oil about if you have a masters. I on the other hand

First number of 5, 10, 20 etc. is the Temp of the oil. if you live in the Artic, 5 is better. You live in the desert 20 is better.

second number is basically the thickness. if your car burns oil then use a 50. In my truck I use 10w30 summer, and 5w20 winter.

For motorcycles, I use Mobil 1 synthetic - I think 20w50




Was that ok for laymens terms scott?

[mtnairlover]

Thanks! Yeah, that actually explains a whole lot. So, last silly question: is 10w40 best? or, will 10w30 be just fine?

[rybo]

Close but not quite. The oil in the case of these types of oils has two thicknesses. The first number is the thickness of the oil when it's cold (0 degrees farenheit) and the second is the thickness when it's hot (200 degrees farenheit) Make sense?

The only time the first number really comes into play is at cold start. If the temperature is very cold a lower number is better.

Scott, Your one to talk to oil about if you have a masters. I on the other hand

First number of 5, 10, 20 etc. is the Temp of the oil. if you live in the Artic, 5 is better. You live in the desert 20 is better.

second number is basically the thickness. if your car burns oil then use a 50. In my truck I use 10w30 summer, and 5w20 winter.

For motorcycles, I use Mobil 1 synthetic - I think 20w50




Was that ok for laymens terms scott?

[rybo]

Thanks! Yeah, that actually explains a whole lot. So, last silly question: is 10w40 best? or, will 10w30 be just fine?

Cathy,

The 10W30 should be fine, but I think most 4 cylinder bikes specify a 10w40. In the summer I run 15W50 in my bike with no issues.

Scott

[Fly boy]

Close but not quite. The oil in the case of these types of oils has two thicknesses. The first number is the thickness of the oil when it's cold (0 degrees farenheit) and the second is the thickness when it's hot (200 degrees farenheit) Make sense?

The only time the first number really comes into play is at cold start. If the temperature is very cold a lower number is better.

Yes, thats why I switch to 5w20 in the winter.

When in cold weather, better to start a car with the lower Farenheit(first number).

[mtnairlover]

Thanks...yeah, fricken WallyWorld...no 10w40 to be seen, so I broke down and bought the 10w30. Guess I coulda driven around for a bit to find what I needed, but meh. I will know better next time.

[rybo]

Cath...it's nothing to worry about, the bike will be fine. Eventually it will be best to pick a brand and weight and stick with it, but for now you aren't doing any damage.

Really the most important thing is to occasionally change your oil, you already do this, so you've got the worst part of the battle licked.

[Fly boy]

Scott,

Does it matter the different kinds of oil for different engine types? My cbr to V-twin cruiser. Or can I use mobil 1 as well in that?

[rybo]

Ben,

The manufacturer probably recommends 10W40 for the CBR and 20W50 for the V-Twin. I've run mobil car oil in both types, but use the 15W50...I've never had a problem and I wouldn't hesitate to run the same oil in both bikes if they were mine. The 20/50 should be fine in the CBR.

S

[pilot]

Something from Mobil's website:

Okay. Let's start with Mobil 1 Racing 4T 10W-40. What does it offer that Mobil 1 for cars does not? Mobil 1 Racing 4T 10W-40 is designed for sport bikes. Most of these bikes have multi-cylinder/multi-valve engines and use a common sump, which means the engine oil lubricates the engine, transmission and wet clutch. So unlike Mobil 1 for cars, Mobil 1 Racing 4T 10W-40 has no friction modifiers, which could lead to clutch slippage.

The motorcycle oil also has more phosphorus/zinc for enhanced wear protection at high engine speeds and high loads.

In addition, Mobil 1 Racing 4T 10W-40 uses different dispersant/detergent technology for better high-temperature performance and engine cleanliness. Mobil 1 Racing 4T 10W-40 is also offered in a different viscosity grade than Mobil 1 for passenger cars. (Updated September 2006)
Perhaps the oil you used has friction modifiers and thus you are loosing power through the clutch?

[Fly boy]

Ben,

The manufacturer probably recommends 10W40 for the CBR and 20W50 for the V-Twin. I've run mobil car oil in both types, but use the 15W50...I've never had a problem and I wouldn't hesitate to run the same oil in both bikes if they were mine. The 20/50 should be fine in the CBR.

S

Thanks alot. I think I am running 15w50 in the CBR right now. Now to take the exhaust off to change the oil in the Vstar - time to save for the oil relocation kit.

[rybo]

Pilot,

I've checked the mobil 1 auto oil that I'm using very carefully. In the 15w50 weight there are no friction modifiers and the oil is safe for bikes. I've used it in the Duc since new and used it in the FZR 400 race bike last year with no troubles. No bike is harder on oil than that thing was. It only used about 2.5 quarts and spent it's whole life between 12,000 and 16,000 RPM...

[irdave]

Is it possible that when you put the tank back down, you crimped/smashed a fuel line? Works ok until you ask for more fuel, at which time it has a hard time trying to squirt it all through... Seen it before...

[pilot]

Pilot,

I've checked the mobil 1 auto oil that I'm using very carefully. In the 15w50 weight there are no friction modifiers and the oil is safe for bikes. I've used it in the Duc since new and used it in the FZR 400 race bike last year with no troubles. No bike is harder on oil than that thing was. It only used about 2.5 quarts and spent it's whole life between 12,000 and 16,000 RPM...

That was just something I found on their website. Spending life between 12 and 16k, sounds like my hard drive, ha.

Cathy, have you found the cause (or did I miss something)?

[Knuckle Dragger]

Hey Cathy still having problems? If so I bet it is a twisted fuel line from when I put it back on along the side of I25. May have to bring it back over to my place so we can pull off the tank and check that out. Sorry it took me so long to get back but I am not too good at really checking this board. Do not worry about calling me if you have problems; mainly with the bike, although I am qualified to handle emtional problems as well (just do not want to know that much about my friends).

[mtnairlover]

Cathy, have you found the cause (or did I miss something)?

Nope, haven't found it. I'm getting used to the new quirks. The Zed definitely has a different start in the mornings. This morning, she didn't even turn over with the first flick of the ignition switch. I was a tad incredulous, but on the next flick, she turned over right away. And, yes that is a very first since I've had her.

One other suggestion was maybe it's an effect of the moisture in the mornings (springtime stuff?)...maybe she's developing allergies. Anyway, with all the talk about various oil weights and the fact that the oil I put in this time around was a change in brand from previous oil changes, might be an effect. Starts are just fine as the sun comes up and the temp warms. She behaves the same during the day as before the oil change (I went from 5w30 to 10w30)...so...?

Anyway, I was mistaken about the mileage...she now has 6600 miles on her, so only 900 to go before the maintenance check. I'm gonna make an appointment and make note of everything, then ask all the pertinent questions when I take her in.

Thanks guys, for all your input. Makes me feel a bit more comfortable about asking certain questions.

[mtnairlover]

Hey Cathy still having problems? If so I bet it is a twisted fuel line from when I put it back on along the side of I25. May have to bring it back over to my place so we can pull off the tank and check that out. Sorry it took me so long to get back but I am not too good at really checking this board. Do not worry about calling me if you have problems; mainly with the bike, although I am qualified to handle emtional problems as well (just do not want to know that much about my friends).

Thanks John. Not to worry bout the emotional stuff...er, I think... ...j/k. I'll call if there are more problems. Hope to see you at MotoHaus. We can discuss possibilities, but maybe it's only a kink. A quick check wouldn't hurt. Anyway, hope to see you at MotoHaus.