Choke and starting question revisited

Found some helpful info on the site so far regarding this topic -

http://xjbikes.com/Forums/viewtopic/t=5 ... +warm.html

My question is -

Got the bike (86 XJ 700 Maxim) back from the mechanic (had the valves and carbs adjusted and synched). I explained that the bike was slow to warm in the morning. He recommended I use full choke and then 1/2 choke and ride the bike w/ 1/2 choke until it warmed up. Was told this could take about 15 miles for the bike to be warm.

So while it was cold (35'F) I went with that story. Now that it has warmed up (60's and 70's) I'm finding that I have to still use the same startup procedure or the bike will die. I'm just surprised that after a new airfilter, plugs, oil change, plus the work the mechanic did and the bike take so long to warm up. Once it is warmed up, it runs fine. FYI - I'm filling it w/ 91 octane.

Suggestions?

 

My mechanic told me the XJ's take a long time to warm up.
Mine on the other hand does not, anything over 60 degrees and mine won't take choke.
Below that I start it with out choke, reving it alittle I then apply a small amount of choke, so it idles.
Careful running it to long on choke could foul the plugs.

 

My XJ is cold blooded too. Starting procedure (needs fuel enrichment) is the same whether it's 40 degrees or 70 degrees. But the whole warm up still doesnt take more than about 5 minutes.

 

How well does the bike idle once it's warmed up? When you engine-brake, do the RPM's drop very fast, or kinda gradually? Any popping on deceleration?

Sometimes cold-naturedness (I just made that word up :mrgreen: ) can be cured by richening up the idle mixture a bit.

As far as octane goes, you're wasting money putting 91 octane in it, IMHO... XJ's were designed for regular octane gasoline. If the timing has never been fiddled with, you shouldn't see any difference in how it runs, unless your gas station uses different additives for regular and high octane fuels.

 

I will go with stereomind on this one, if the bike is running slightly weak it will require longer use of choke, also i noticed that if you let the bike sit and warm up once its of choke you can set the idle and it runs great, then go for a run and after a short ride the idle will rise to around 2k. I found that with a slightly rich mixture you have the choke on for a much shorter time and once its of choke and you set the idle it tends to stay where you set it

 

Once the bike is warm it runs fine.

My startup procedure as follows -

1. full choke for one minute
2. reduce to 1/2 choke for five to seven minutes (if i reduce the choke completely during this time rpms drop slowly and then the engine dies).
3. once on my way i need to rev it a bit higher or it will die at the first couple of stop lights (the bike sounds like it is congested w/ phlegm and its trying to cough it out)
4. after fifteen minutes the bike seems to be warm and runs fine. no hesitation from the throttle and pulls off the line good too.

 

Mine is:

1. Full "choke" to start.
2. Reduce "choke" to achieve about 1,500-2,000 RPM or smoothest idle.
3. Ride for a few blocks.
4. Reduce "choke" to maintain ~1,000 RPM idle at next stoplight/sign.
5. Turn off "choke" when I remember it and prepare to increase it if needed at next stoplight/sign.

I only ride about 3.5 miles each way to/from work and usually the last half is w/o "choke".

 

tsxjrider i'd say your bike sounds like its running a bit lean, sounds pretty much same as mine was, if i rode it till it was fully warm then set correct idle it would need quite a long usage of choke the next time i started from cold until it would idle without a problem, i just gradually upped the mixture until i was happy with it. Now i start it with full choke and reduce as required, by the time i get my helmet on choke is almost not required, ride for a few hundred yards and choke is off and idle is great.

 

Mind you I've been riding to work in freaking 40 degree mornings so she's a bit more stubborn as a result. If it ever warms up around here maybe I'll try the idle air screw trick to try and get a faster warm up.

 

tsxjrider,

When was the last time the STARTER PASSAGE were cleaned. I mean like "eat off of" clean. Did you watch the ~10ft stream of carb cleaner spray out??
If those passages are SLIGHTLY blocked, the warm up become more tiresome.
When these passages are clean, the full choke(enrichment) lasts ~5 secs
1/2 open last for ~15 secs then NONE.
This is Texas temps, but add a few more seconds for each -10F you are under 75F.
EDIT(This is applicable to well tuned carbs too! If it is out of sync or mixture is incorrect things will not be the same)

You can add your bike's info in your signature, and your location both in acct settings.
Also add yourself to the XJBikes Map http://www.xjbikes.com/dfmaps.html

 

I just got done cleaning my carbs and reinstalling them on my XJ650. Noticed a big change for the better with regard to starting. If the starter enrichment circuits are all completely clean the engine will reliably start without use of the choke, even here in Minneapolis's 43 F temps in the recent mornings. It will idle a bit rough until it does get warm, but once it starts, hop on and go with the choke off. It will idle well after only a mile or so.

As others have said, the jets are properly clean when a stream of carb cleaning fluid shoots out 8-10 ft or so. This is critical. I thought mine were clean, and had to go back and re-do them to get them REALLY clean as they need to be.

 

my 85' X is pretty cold blooded by my standard but warms up decent. I vary the choke depending on temps. My bike will start just about any temp even without choke(enrichment) but will barely idle. I bump the choke on until the rpms stay about 1500 or so. only take about 10-15 sec. til the idle starts to climb and I kick the lever down a little more. If I am in a hurry I'll take off with 1/2 or less choke and within 1 mile I can kick it off all the way and all is well.

 

Is it possible, that by leaving the choke full on for so long (as well as 1/2 choke) that I created the "congested" throttle problem myself?

 

Exactly.

I always turn the choke off before starting to ride, it idles low, 800-900 the first few lights, but then it's fine.

@ tsxjrider.
I would say that the choke being on is definetly the phlem congested issue.
If I try to move my ride with the choke on it makes that low grumble of a noise and doesn't have much push.

 

When my bike is dead cold, I put the Enrichment right-over, full ... and then hit the Start Button.

The bike starts right up and I start inching-off the enrichment. I let it "Fast idle" for a few moments and then just go.

While I'm riding ... I'm inching-off that enrichment and listening to the bike run. If it will go without the extra gas ... I thumb it off and keep going.

If it feels like it still needs a little help ... I regulate it like the kitchen faucet.
Maybe a little
Maybe a little more.

Once it warms-up ... off she goes and I'm in the wind!

 

Half choke, fires every time.
A little choke massage till warm, not long at all.