Hard Starting

[blue giant]

I'm sure my bike has never run better since I purchased it mid August and started going everything, changing the fluids, replacing the fuel lines, cleaning the carbs and petcocks and synching the carbs and adjusting the idle mixture. The past two mornings and yesterday afternoon my bike would not start when cold. As usual I placed the choke on full and pushed the starter button and it cranked and sputtered but would not fire and stay running unless I held the throttle open.

Does it sound like it may be too rich at idle?

[egsols]

Mine usually starts no problem, but if it sits for a bit I just have to run prime for a few seconds and it fires up right away.

[79XS11F]

The colder it is the richer you will want it to be for starting Paul. If it will not start on full chock and is tuning over fast enough you may want to turn the idle jets out a little bit and it may only be required in the cool season. Cool air is denser so a bike is if anything running a little leaner then it would in warm weather.
If it will fast idle on its own after you get it started with that little bit of throttle then don't worry about it too much until it get real stubborn.
Rob

[malber]

What weight oil are you using?

[blue giant]

Originally posted by malber
What weight oil are you using?

20w50 and I meant cold engine more so than cold out. I was told on the weekend that it would be soon time to switch to 10w40.
It was parked in my garage both mornings and was out in the sun at 4pm yesterday so temp would be around 70f.

Rob- I did turn the pilot jets in one turn last night to see if that would help with the rumble and back fire in the exhaust when downshifting. They were at 2.5 turns out, should I try 2.75 or even 3 turns out?
I'm just wondering why I have to open the throttle now to get it to fire and even then it takes a few tries before it will stay running.

Paul

[malber]

With the cold New England season approching I've switched to 10w30 and I love it. I may run it all year long. Last fall, my first year with the bike, I used 20w50 due to the advise of people on the boards, not realizing that they lived in Texas. I had the same problems starting in cold weather that you did. In the spring I did the seasonal oil change and I used 20w50 again looking forward to the hot summer months. I ended up having leaks with 20w50 and still had troubles starting. I think I'll stick with the 10w30.

[blue giant]

Originally posted by malber
With the cold New England season approching I've switched to 10w30 and I love it. I may run it all year long. Last fall, my first year with the bike, I used 20w50 due to the advise of people on the boards, not realizing that they lived in Texas. I had the same problems starting in cold weather that you did. In the spring I did the seasonal oil change and I used 20w50 again looking forward to the hot summer months. I ended up having leaks with 20w50 and still had troubles starting. I think I'll stick with the 10w30.

That's interesting Malber, when I bought the bike the PO told me he was using 10W30. When I asked around I was told to use 20w50. Now I'm confused, but for the cost of three liters of oil it might be worth a try.

Thanks,

Paul

[jeffe]

In colder weather I find that my 78 starts better on the first notch of the "choke". After it fires I then pull it all the way at untill it's ready to get pushed back in. My 2 cents

[79XS11F]

OIL ... when I was using my first XS1100 I was told by the Yamaha dealer that 20/50 weight oil is TOO HEAVY. It over works the oil pump and can affect overall oil supply rates. This being more true during the cooler parts of the year. They told me to use 10/30 in spring and fall and 20/40 in the hot summer months. They also told me to STICK to the oil change schedule and if anything in the hottest part of summer with a modifies engine .. change it more often. they also said to use reasonable quality oil. Heaver oil in cooler times of the year will reduce cranking speed which "may" affect start-ability but the first listed issue is more serious. Those oil rates are by the way the same as the manual recommends.

Paul.. start by returning your pilot jets to where they were or turn them back out 1/4 turn at a time.

Rob

[planedick]

Maybe I'm qrong...

I was led to believe that the numbers, 20W50 meant that in the cold the oil was thinner and when hot it was thinner. Of ourse it doesn't seem to be that way, but it's probably just an advertising gimmick anyway

[79XS11F]

No it means the oil will preform like a 30 weight and like a 50 weight depending on conditions and the 50 weight part is the part that is not a good match to this engine.
Rob

[John]

20W50

The 20W means that in cold weather it has the viscosity of a 20 weight oil, and the 50 means it has the viscosity of a 50 weight oil in hot weather.

[TopCatGr58]

Hey Giant,

I don't live where it gets as cold as where you live, so I can run 20/50 all year long, but if I lived up north, I would switch to 10/40 or 10/30 for those 30 degrees F and colder climes!

You might want to pull your float bowls and check to make sure your enrichener jets in the bowls are clear and flowing!?

However, having to open the throttle to get it to start does kinda hint at slightly rich, or it could also be that the pilot/enrichener circuit is not flowing adequately, and you may be pulling in fuel thru the main jets when cracking the throttle??

But usually opening the throttle actually reduces the ability to create vacuum to pull fuel thru the enrichener circuit, causing it to be lean, which usually makes it harder to start a cold engine!?!?
T.C.

[planedick]

That's what I t hought...

"The 20W means that in cold weather it has the viscosity of a 20 weight oil, and the 50 means it has the viscosity of a 50 weight oil in hot weather. "Quote from John"

That's just what's advertised. You aren't gullable enough to really believe that are you? I have an oil pressure guage on my bike and when it's cold the oil pressure is high and when the oil gets hot the pressure is lower. Now, does that sound like it's viscosity is lower when it's cold and higher when it's hot? Just more BS from the oil companies.....

The facts outweigh the BS IMHO

[Crazcnuk]

What he means is that the oil, when hot does not get thinner than 20wt, and when it's cold it doesn't get thicker than 50wt.

The owners manual, for my 80G specifies 20w-40 for warmer climates and 10w-30 for cooler temperatures.

Basically it calls for 20w-40 for 41F and up and 10w-30 for 60F and lower. So pick your oil based on what the majority of the drving will be done in. If the temp in your area rarely goes below 40F then use the heavier oil. If, like me, your ina country where the temp is not going to get up to 60 for a few months, use the lighter oil.