GS750e cold (<55 f) starting problems

[evanparker]

i recently got a GS750e. I had been going through archived posts and looking to identify the starting issues i have been having. i thought it was the carb boots (it had a small leak), but i've fixed them and evidently i was incorrect.

this is what the bike does:

when warm engine/ ambient temp is >55 degrees bike will start right up, no drama at all.

when it's below 55 degrees air temp, or i park the bike in the shade and giev it enough time to cool down, the bike will not start until about 40 seconds or more of straight starting has been put on it. when you start to turn the starting motor it will just spin it, about 20 seconds in it will start to gurgle a little, and it will slowly start to put-put until it will eventually start up.

This is the same whether on the GS battery or on an external source, meaning it's not my battery. I have been starting it on a engine-off car battery, and it will start every time, given enough turns. The amount of turns however, if too many for the little motorcycle battery to provide everytime i need to start the bike.

it's not my carb boots because I just replaced them all and tested for a leak using the starting ether method. there was a leak before, but it's fixed and i haven't seen any substantial change.

i need to have this bike on the road this week. can anyone give me any ideas?

also as incentive, i will post some hott pictures of my bike

 

[tkent02]

What are you doing with the choke and throttle???

What are you doing with the choke and throttle???

nice looking bike, too.

 

[evanparker]

I am not touching the throttle, choke out. it should be able to start without my hand on the throttle whatsoever from what i understand.

 

[evanparker]

i just read another thread about blowing through the carb breather hoses... but the BS carbs don't have those on this application.

i had an idea though, what about the rubber boots on the oposite side of the carbs? those leaking could cause a wierd air problem.

 

[arveejay]

Beautiful bike, sounds like the choke circuits are plugged.

 

[tkent02]

Wierd air problem...

Wierd air problem...

i had an idea though, what about the rubber boots on the oposite side of the carbs? those leaking could cause a wierd air problem.

Not likely, since you are controlling fuel directly with the choke. Those boots may cause problems running with the engine warm and the choke not being used.

I would guess arveejay is right. Does the choke have any effect when it is pulled in or out when the engine is running? Is the cable mechanism working, all four carb's chokes are moving?

Note this is not a true choke, just an enrichment device, with separate fuel passages in the carbs.

 

[KEITH KRAUSE]

As mentioned, make sure the choke cable has the correct slack and the chokes are operating correctly.
If so, then it appears to be the mixture is too lean. Most common causes would be a blocked pilot circuit passage or the mixture screws are set too lean. Checking the screws is easier than cleaning out the complete pilot circuit. So I'd check the screws first.
If you inherited this problem from the PO, then you may not know how the screws are adjusted. If the factory caps are removed, then try adjusting them. Use a good fitting tool because the screws can be stuck. They are generally 1 1/2 turns out from the factory, give or take 1/2 turn. They should be adjusted using the highest rpm method. For simplicity/testing, you may also just seat them lightly and count how much they were out. If they seem set too lean, then add another full turn. If that doesn't help, then I'd try a partial passage cleaning. Remove the screws and o-ring and carefully shoot some carb cleaner in there. No substitute for a good cleaning but it may help. Re-set the screws to about 1 1/2 to 2 turns out and test. If you try as much as 2 1/2 turns out and it doesn't help, then I think the carbs pilot circuit needs a good cleaning.

 

[Guest]

There are brass tubes that Come out of the carb body and rest in the float bowl. If your choke cable is operating than these are most likely clogged.
I've never seen Keith suggest a short cut in cleaning carbs. He must be getting soft.:wink:
Check out this carb cleaning series. It is a great step by step guide. Just do this and you will not be sorry.
http://www.thegsresources.com/gs_carbrebuild.htm

 

[KEITH KRAUSE]

I've never seen Keith suggest a short cut in cleaning carbs. He must be getting soft.:wink:

One reason I mentioned that short cut was because he said he needs to have the bike on the road this week. He sounded in a hurry.
To tell you another reason though, twice in the last several months a couple of friends with quadrunners had some cold blooded/low rpm hesitation problems and both times a good shot of high pressure was able to clear the passage. It worked both times. I've done this before. Nothing else was done so we know it was just a blocked mixture screw passage. I know that no carb cleaner was used with the one bike, just air. Dirt bikes are more prone to getting grit stuck in the passages. I also overheard a mechanic several years back at the local Suz/Kaw/Honda dealer advise a customer to try the same thing before bringing his bike in for service. It's a common "trick" actually.

 

[evanparker]

ok awesome guys. i apprciate the help.

I actually turned the bike on today in the cold after having it running this afternoon, and it ran for 3 rotations, then died. and before i even read this stuff, i was suspecting the carbs because of the way this worked.

i'm confident about this working, so i'm gona check it out this weekend. thanks guys!

 

[Guest]

C'mon Keith, I was just razzing ya:-D

 

[KEITH KRAUSE]

C'mon Keith, I was just razzing ya:-D

I knew that.

 

[evanparker]

ok so, i opened it up. some numbskull before me modified the choke to non stock to fit beside the cams on the engin. this doesn't work, and it turns out the cable was getting pinched and wasn't choking all the way. so, i'm ordering a new one or fabing one up at work tomorow. i'm gona figure it out in the morning.

 

[rphillips]

You can use the choke without the cable, just find the choke rail on the left side of the carbs, & pull the rail out as far as it will go. You will need help, if your clutch safety switch is still working, and not been by-passed.