1999 IS cold weather carb issues - found - fixed

[Pete]

Just FYI.

When cold weather set in the 1999 IS began to have cold start and idle issues (slight miss and hesitation).

Pulled the carbs and cleaned the idle passages, sure enough the #3 carb had a whitish substance in the pilot screw chamber. Not real sure what it is, may have been some water intrusion, suspect condensation dripped into the needle cavity thru the pilot passage in the carb barrel and set for some time. All others were clean.

This particular IS seems to run lean, so I checked the pilot adjustment on all 6 carbs. 5 were set at 1 and 1/4 turns, #6 was set the 1 and 3/4 turns. Seems sometime in its past life this bike lived at altitude (Colorado, prior owner) and someone went wild with the high altitude adjustment. No wonder it seemed lean. #6 seems to be just a screw up. Corrected them all to 2 and 1/4 turns. 

Should get it reassembled tomorrow for a road test. I should have check those pilot screws before, my mistake.

I knew this bike had  been used at altitude, I should have check the adjustments as part of my general checkup when I bought the bike. Will not make that mistake again.

[9Ball]

When I cleaned my carbs a few years back I had the same white deposits in the pilot screw needle area (I seem to remember it being present in almost all the carbs, not just #3).  I bought my 1999 standard new in Denver and lived there until '06. Up until I moved to Wisconsin, my bike was ridden mostly in Colorado, Idaho, Wyoming, South Dakota, and Utah.

I never fooled around with the pilot adjustments and the bike ran well at altitude.  When I moved to Wisconsin, the plugged slow jet symptoms became very noticeable.

I wonder if the deposits might be something from the gas formulation.

[Pete]

I wonder if the deposits might be something from the gas formulation.

Could be. I suspected moisture, although I found no evidence of moisture anywhere else. In talking to the original owner, I think the problem had been there for some time, As he indicated it had been very cold natured during startup.

The 1 and 1/4 settings for the pilot screws would have caused that at our altitude (700 ft). The white deposit seems to be causing the miss at idle.

While Honda suggest 1 and 3/4 setting for altitude compensation. The 1 and 1/4 settings were a little strange and the DPR6EA heat range plugs in the bike were a cold climate recommendation.

The carbs did not appear to have ever been serviced. neither had the air cleaner. I wondered if someone had been trying to compensate for the very very dirty air cleaner I found in it.

Anyone ever see this combination used at altitude? or for a dirty air cleaner?

Thanks

[CowboyBlue]

I too have a 1999 IS. Under 40 degrees it will NOT start. Ever. I have checked the filter. It's K&N. It's fine and recommended 50K miles for cleaning (however i will half that). I adjusted the pilots per the manual and fixed the rough idle it had when I purchased it at 50K miles. I will replace the plugs next. Recommendations? it sucks that I have such a great bike for cold weather and it will never start.

[hubcapsc]

I too have a 1999 IS. Under 40 degrees it will NOT start. Ever. I have checked the filter. It's K&N. It's fine and recommended 50K miles for cleaning (however i will half that). I adjusted the pilots per the manual and fixed the rough idle it had when I purchased it at 50K miles. I will replace the plugs next. Recommendations? it sucks that I have such a great bike for cold weather and it will never start.

You might know this already, but... look down at the carburetor end of the choke cable when you
are putting on the choke. If you don't see parts sliding, you're not pressing on the choke
lever hard enough. The place where it feels like it is done is actually the place where
stuff starts to engage... don't break it off or anything, but look down there, and you'll
see the parts move...

-Mike

[Gary]

I too have a 1999 IS. Under 40 degrees it will NOT start. Ever. I have checked the filter. It's K&N. It's fine and recommended 50K miles for cleaning (however i will half that). I adjusted the pilots per the manual and fixed the rough idle it had when I purchased it at 50K miles. I will replace the plugs next. Recommendations? it sucks that I have such a great bike for cold weather and it will never start.

You might know this already, but... look down at the carburetor end of the choke cable when you
are putting on the choke. If you don't see parts sliding, you're not pressing on the choke
lever hard enough. The place where it feels like it is done is actually the place where
stuff starts to engage... don't break it off or anything, but look down there, and you'll
see the parts move...

-Mike

Good point, as Mike said check out that choke cable under the chrome plate on the left side for any remaining threads on that adjustment screw. Mine was sliding but not far enough to engage. My cable is stretched and I have no more room for adjustment. I'm now at the extreme max adjustment and now it will start. Ordered a new cable and still need to install.

[CowboyBlue]

Thanks. I will check that. When it feels engaging is about half way, then it gets hard and I really pull it/push it down hard. So that said, I never thought of that. Good idea. I will check tonight.

[John U.]

The right hand carb slide piece can be moved directly with a finger while you press on the choke lever. That removes some of the stress on the cable and helps to get the choke all the way on. I've been doing that for years because I'm afraid of breaking the cable or some other part of the choke engagment system.