85 Big Red and cold weather starting problems? Any ideas ?

[trike savior]

nothing wrong with ether (starting fluid) as long as it says on can it has upper cylinder lubricant in it (cheap formulas do not). careful with heating the carb cause it can make your worst nightmare of a fire come true. whoever said pull spark plug and keep inside by the fire, seriously, that doesnt help when your trying to pull thick cold fuel through a tiny pinhole in a carb jet. as many are saying the 250 sx has an enricher valve instead of choke (throttle) blade type system in the smaller and older bikes. give honda a break it was their first try at it. no offense to anyone but trying to use a screw to make the hole bigger might not be the safest fix on a $100 carb if you break it. either give it a quick hit of starting fluid or use the drill bit method. it sucks but if no one knows the proper size find a friend with a bit set, see where its at now and incrementally go up from there till you find one that works.

QUICK TIP with cold starting 250 es and sx's. do not give it any throttle when you are cold starting. i know that worked great on everything else you have ridden but these carbs have a carb slide and throttle blade that work together. by leaving the throttle closed, the throttle blade acts as a choke blade when the rest of the carb is adjusted properly.
proof of theory: when you cold start these bikes many will die out if you try to rev it right after it fires up, you have to let it idle with choke on before it can be reved.

[Elevator]

Carb on my Red is this troublemaker Keihin QA01. In cold weather, starting is very frustrating because of cold start jetting. Honda made repair kit 06161-HA8-305 of those cabs and finally I got one NOS set. I tried to find pictures of the kit assembly in all forums with no results.
So now I try to explain this case


This is the well known troublemaker Keihin QA01


Biggest problem is inside of the carb, starter jet. Repair kit included new jet and this old one have to remove. Now you need


Honda's original repair instructions




There is old starting jet and new one


In the hole of starting jet was some dirt. I used ultrasonic cleaner for this case.

My wife loves my hobby. Specially she loves ultrasonic cleaner in the kitchen


Now you need tiny , be careful!


Done


For now you need to install new hoses.




Tomorrow I will instal carb in the Red. Im sure this will help a lot with this cold start problem
There is more pictures of that repair
https://elevator.kuvat.fi/kuvat/BigR...old+start+set/

[Big G]

Thank you for the tutorial. One of these days I'll fix my cold start '85 250ES. Such a pain in the winter.

[hublake]

A simpler solution is to keep it in a heated shop. That is what I do in NE Michigan.

[mendoAu]

My 84 200es starts with just a flick of the starter switch in warm weather but in cold weather I've learned that even tho the starter sounds like it is kicking the engine over fast enough jumping it with a fully charged 12v. deep cycle makes all the difference. I don't ride as far or as often in cold weather and kinda lean towards the battery isn't getting a full charge combined with the cold and sitting idle for a couple days it's just a little to weak to crank fast and give a good strong spark. Yep...to cheap to get a new battery....ha! I live off the grid and don't have power after bedtime and when the generator is on I have limited power for "extras" otherwise I'd have an electric blanket over the whole bike all the time. Gotta laugh about the "heated garage" thing, I wish!!! It get's so wet/cold around here that I get mushrooms growing on my rubber boots if I leave them outside to long.
I'll add that you have to use common sense about electric things outside in wet/cold situations. Absolute that you use a waterproof tarp over that blanket. Trickle charger wouldn't hurt either.