Cold starts require partial throttle

[Moja]

Sorry if this has been asked previously (I searched first and didn't get any hits on anything resembling it.)

My completely stock 2000 which I just got (and love!) will not start unless I open the throttle partially and hold it up around at least 2000-2500 RPMs for perhaps 3-4 seconds.  Then I let it go and it burbles happily and smoothly with no hiccups, hesitation, or stalls during take-off.  I can usually disengage the choke within 1/2 mile or less and it stays running perfectly.

I'm told that open-throttle starts will foul the plugs over time, and should generally not be required.  I would love to hear from some other owners if this is common, fixable, or something I shouldn't even worry about?  I've had other non fuel-injected bikes behave similarly, so I figured this was just typical of carburation.  BTW, I assume our petcock is vacuum-operated?  I have tried leaving the key in the On position for a good 20-30 seconds before starting up to see if that would suck some fuel in, but there was no discernible improvement.  And yes, when its warm it fires right up and does not need any throttle.

Thanks in advance for your ideas!

Colin

[roboto65]

Well I would say that your slow speed jets are getting clogged. I would try some Seafoam which you can pick up at your local Autozone or any other Autoparts store.... Also there is no fuel pump just the diaphram which shuts fuel off to the carbs when you shut the bike off  so turn the key on and waiting does nothing except run your battery down   ....

[Greg Cothern]

Yep slow speed jets are partially clogged.  If you can get it running, put a fresh tank of fuel and Seafoam as already suggested and ride till ya have to fill up again.  If this does not improve the situation quite a bit then ya might need to pull the jets and clean them manually.

[Moja]

Thanks!   I will pick some Seafoam up on the way home today.  As luck would have it, I'm just about on fumes anyway and was going to fill up tomorrow  

Is this likely to have any impact on my gas mileage?  I seem to only be getting about 80 miles (about 60-40 city/hwy) before I have to switch to reserve whereas I've heard that 100 or more miles is more common (or should I be starting a new thread with this question? )

[roboto65]

Nah 80 miles is a little low but within limits I hit it about 87 or so but thats the way I drive too and that affects mileage the most hehehehehehe Twist it all the way and hold on hehehehehehe

[DC Smith]

I get 100 miles or more before reserve. I drive coservatively.  Hopefully the Seafoam will increase your mileage.

[Moja]

I don't feel like I rag on the bike unduly, but its possible I'm a bit more lead-fisted than most since my primary ride is a Yamaha R1.  Course, if Honda didn't want us to hammer the things, they wouldn't have dropped crotch-rocket engines in 'em, right?  Still, despite using my fair share of throttle, I think 34 mpg is way low - I did some searches and see more people reporting well into the 40s.

Anyway, I filled up the tank near the rim, dropped 3.5 oz SeaFoam on top of that, and just blasted out about 70 miles up and down I-35.  I will go fire the bike up again in several hours when I go to bed and see if that had any effect, and then again in the morning & report back here.

Thanks to everybody for all the great, fast responses!

[Lurkin]

If it were the slow spped jets, wouldn't he also be seeing some low rpm running problems after it's warmed up?

FYI, my 01 does the same thing.  It's actually easier to start with a bit of throttle and no choke, then it is with choke and no throttle.  Now maybe we do have the same problem, but mine runs fine after it's warmed up.

I've been playing with cold start methods the last few weeks, as the choke and no throttle method seems to make it start hard.  I do have the jets and shims, but have not taken the time to rip it apart and put them in as I have not worked on CV carbs before and am a bit leary of doing it by myself.  I need a wrench session that I can make it to

[Lurkin]

Oh yeah, my milage usually averages about 39.  But that totally depends on if it's highway or city milage.  I've ranged between 33 and 46.

[Greg Cothern]

Its about time for a wrench session, I have pulled carbs a few times LoL.

[Moja]

Well, unfortunately that didn't work.  There is no way its starting without throttle.  I don't know if this is wishful thinking, but it did appear that it was closer than normal to doing so.  ie. there were a couple of chugs mixed in there as opposed to what is normally just dry cranking without a hint of a spark.  But honestly, I can't say that that didn't happen sometimes before because I've just grown to habitually give it gas when I start it.

How hard of a DIY job is it to pull the jets and manually clean, and is there a HOWTO on the MOOT site?  Or should I leave this one up to a pro?  Or are any of you pros down in the Austin area feeling thirsty for all the cold libations you can drink in trade for some assistance?

Is there any harm/benefit to finishing out this tank and trying another small dose of SeaFoam, or should I have seen something already?

[roboto65]

Really I would say that you have not even givien the Seafoam a chance to work just keep running it everytime you fill up and till that can is gone then see what happens.........

[Greg Cothern]

You will need to run a few tank fulls through to start seeing good results.
I do have a write up on the "tips and tricks" page on the main MOOT site for the jets/shims.
My son is at UT and might be talked into helping, been a bit since he helped but he knows what is needed.
Dont take it to a shop they will charge you a big fee for something you can do yourself.

[Moja]

You will need to run a few tank fulls through to start seeing good results.

Okay, I will use up the entire can over the next few tanks before I pester your son

Thanks to all for the help!

[Greg Cothern]

Oh he needs pestering LoL!!!  He is starting his second semester at UT.