Join Date: Apr 2020
Location: Baton Rouge, LA
Carburetor Help - Unable to Cold Start After Rebuild
I'm having issues with cold starting after recent carb cleaning and rebuilding that I hope I can get some help with...
Here's the events leading up to this issue. I have a 2007 KLR with 11,660 miles that I haven't ridden in several, or more, months. I've been riding my other two bikes recently at the expense of my KLR. I didn't intend to stop riding it altogether it just kinda got put on the backburner so I didn't prepare it for storage and now I'm paying the price...
When I took it out of the shed a couple of weeks ago, I found that the fuel petcock diaphragm had failed and leaked fuel all down the side of the stator case, ruining the paint on the case. I generally try to avoid ethanol gas altogether but I must have put some in the tank at some point and left the fuel tank was about 1/2 full. When I looked in the tank, I found, as you probably have guessed by now, that it was full of rust.
I ordered the Carb Rebuild Kit, Extended Pilot Needle, Coaster Enricher Diaphragm Kit, and Petcock rebuild kit from Eagle Mike's to rebuild the carb and petcock after a through cleaning. I used 4.5 gallons of the Evapo-Rust branded rust remover as well as water, denatured alcohol, gasoline, diesel, followed by more gasoline to get the tank back in working order (I will say the tank came out really great: highly recommend the Evapo-rust product!). I was sure to ensure the float height was set at 17.5mm when reassembling the carb. I didn't see any rust in the carb but all the float needle and coaster diaphragm were all badly damaged/deformed. I also replaced the fuel line. I initially set the pilot needle to 1 3/8" out from the seated position. I also cleaned and reoiled the stock air filter.
After reinstalling everything bike on the bike, I found that it was nearly impossible to start when cold. Previous to this fiasco, cold starting always required full use of the "choke"/enricher for the first few seconds of starting and running. Now, I find it won't start with or without the use of the choke. I rechecked the float height using the clear tube method and that method shows the level to be correct as well.
The only method, I've been able to consistently start the bike with is to 1.) set choke to off (not enriched), 2.) apply full throttle briefly while cranking over, 3.) releasing the throttle and starter, then 4.) cranking a second cycle without throttle application. It starts right away and then idles well at 1200 rpm. After running, even briefly, it then starts and runs well. I found this method through desperation and experimentation, I never had used the throttle at all for starting prior to this issue.
I took it on a test ride and the engine runs, accelerates, decelerates very well: better than it ever has. No issues whatsoever.
I am the second owner of this bike. I have owned the bike for about 7 years now. I have never checked the valve clearances or compression before and I'm unsure if the the PO had or not. However, I was not having any starting issues prior to the recent carb work.
The fuel/air system is all stock and has not been modded with the exception of the Stead Engineering Cable-less choke.
I have also ordered the manual fuel petcock: I'm done with the vacuum-operated one!
Any recommendations on what might be causing the issue or what steps to take would be greatly appreciated.
Last edited by Eric Frazier; 04-28-2020 at 02:15 PM.
Reason: Clarification of use of starting procedure