No cold start/idle without choke

[DBG]

I just bought this bike, and the previous owner called it "cold natured," a very technical term. The mechanical fact is that it won't run unless warmed up. I have to sit and let it run with the choke on for quite a bit before it will idle properly. Once it's warm it runs and sounds great. I noticed right off the bat that the spark plug was bone white, indicating that the mixture was lean. Some cowboy that owned it before me thought he would give this little scooter a pair of balls by drilling a buncha holes in the muffler... :lol: I drilled out that plug on the carb and adjusted the pilot screw. This helped quite a bit, but still no glory without letting it warm up on the choke. I don't really notice any change in the power across the throttle, and it has a pretty good top end (70mph+) unless there's any head wind (~60mph). Is this something that's just inherent to this motorcycle? Or could it be that I need to detail the carb and soak it in some solvent? I mean, this thing won't go two feet without stalling unless the engine's hot. Any tips appreciated.

[blaine]

I just bought this bike, and the previous owner called it "cold natured," a very technical term. The mechanical fact is that it won't run unless warmed up. I have to sit and let it run with the choke on for quite a bit before it will idle properly. Once it's warm it runs and sounds great. I noticed right off the bat that the spark plug was bone white, indicating that the mixture was lean. Some cowboy that owned it before me thought he would give this little scooter a pair of balls by drilling a buncha holes in the muffler... :lol: I drilled out that plug on the carb and adjusted the pilot screw. This helped quite a bit, but still no glory without letting it warm up on the choke. I don't really notice any change in the power across the throttle, and it has a pretty good top end (70mph+) unless there's any head wind (~60mph). Is this something that's just inherent to this motorcycle? Or could it be that I need to detail the carb and soak it in some solvent? I mean, this thing won't go two feet without stalling unless the engine's hot. Any tips appreciated.
Sounds like your still running lean.I found the biggest difference in performance when cold was when I shimmed the needle.Almost like two different bikes.Would start much easier when cold & idle smoother.The American models run even leaner than the Canadian ones do.
:) :2tup:

[Water Warrior 2]

Even the Canadian bikes are a little cold blooded but run fine after getting warmed up. Full choke to start and reduced choke as it warms up and the idle starts to get too high.

You will get the hang of it.

[alantf]

Even the Canadian bikes are a little cold blooded but run fine after getting warmed up. Full choke to start and reduced choke as it warms up and the idle starts to get too high.

You will get the hang of it.

My European's the same set up as the Canadian, & I never (well - hardly ever) need the choke to start. The temperature hardly ever gets below 10ºC (50ºF?). Do you need the choke when it's this temperature with the Canadian bike?

[blaine]

My European's the same set up as the Canadian, & I never (well - hardly ever) need the choke to start. The temperature hardly ever gets below 10ºC (50ºF?). Do you need the choke when it's this temperature with the Canadian bike?
I always did on mine until I adjusted the idle mixture and shimmed the needle.If it was close to freezing to below,she was really cranky.After the mods,she would start at 10c with no choke.
:) :cool:

[Water Warrior 2]

First start of the day needed choke no matter what the temp. Blaine appears to have hit the nail on the head. Carb mod and adjustment is needed for overall satisfaction. I do sometimes wonder if the Canadian bikes are the same as U.S. bikes. The cages here meet U.S. requirements so the bikes may suffer the same fate.

[blaine]

First start of the day needed choke no matter what the temp. Blaine appears to have hit the nail on the head. Carb mod and adjustment is needed for overall satisfaction. I do sometimes wonder if the Canadian bikes are the same as U.S. bikes. The cages here meet U.S. requirements so the bikes may suffer the same fate.
I also needed to adjust & shim my older 454 as it was very lean from the factory also.
:) :2tup:

[DBG]

Did the needle shim today. Unfortunately can't test it due to weather. I did however have a much better response playing with the pilot screw at idle after the needle shim job. I have the pilot screw set at 2.5 turns out. Similar to anyone else?

[blaine]

Did the needle shim today. Unfortunately can't test it due to weather. I did however have a much better response playing with the pilot screw at idle after the needle shim job. I have the pilot screw set at 2.5 turns out. Similar to anyone else?
Yep,2.5 turns is a good starting point.You will need to fine tune it when the bike is warm.Out is rich,In is lean.
:) :cool:

[DBG]

What is the best way to determine when the pilot is set right? I'm spoiled- the Harley just requires pushing a few buttons to adjust the fuel map- dunno much about carbs. Am I looking to eliminate all back popping when decelerating? Right now its humming nice and smooth at idle, but if I rev it, it pops on the way back down. Is that ok? Or am I looking for something else?

[Water Warrior 2]

What is the best way to determine when the pilot is set right? I'm spoiled- the Harley just requires pushing a few buttons to adjust the fuel map- dunno much about carbs. Am I looking to eliminate all back popping when decelerating? Right now its humming nice and smooth at idle, but if I rev it, it pops on the way back down. Is that ok? Or am I looking for something else?
If it is the tail pipe popping a bit I wouldn't be too concerned. If the bike runs smooth otherwise I wouldn't touch a thing. But be warned that is just my opinion and have been wrong in the past.

[blaine]

What is the best way to determine when the pilot is set right? I'm spoiled- the Harley just requires pushing a few buttons to adjust the fuel map- dunno much about carbs. Am I looking to eliminate all back popping when decelerating? Right now its humming nice and smooth at idle, but if I rev it, it pops on the way back down. Is that ok? Or am I looking for something else?

The best way is with the bike at operating temp.Adjust in or out to were the bike idles smoothest.A little popping on the way back is nothing to worry about,but if you adjust further to the rich side (out),it should disappear.
:2tup: :)

[Road_Clam]

What is the best way to determine when the pilot is set right? I'm spoiled- the Harley just requires pushing a few buttons to adjust the fuel map- dunno much about carbs. Am I looking to eliminate all back popping when decelerating? Right now its humming nice and smooth at idle, but if I rev it, it pops on the way back down. Is that ok? Or am I looking for something else?


I'm assuming your location is TX ? So you will be generally riding in warm temps, so if your pilot circuit and air screw is a tad lean it's no big deal. However those of us way up north who ride in the colder weather, the correct mixture and jetting of the low speed circuits is critical. Where you can get away with "lean" I can't. So I tend to adjust on the rich side . This aids in good cold weather start-ability, and proper low speed running while the engine is first warming up. So many cold weather riders complain that they consistently have to ride with the choke on for 15 min or longer until their bike will idle and run smoothly. This is the tell tale sign of "too lean" low speed circuits. I'm curious when you adjusted your air screw was the tamperproof plug already removed or did you remove it ? Maybe the previous owner had it removed.

[DBG]

Yup down here on the TX coast on an island called Galveston. I removed the plug myself. I then tightened the adjustment screw all the way closed, and then began working my way out .5 turns at a time, all the while listening to the motors response. In between 2 and 2.5 CCW turns, the hiccups stopped and the idle slightly increased and leveled out. I wasn't able to take her for a ride due to weather. Hopefully I'll be able to this weekend.

I agree- the fact that I live in a warmer climate should result in easier cold starts. That's why I feel that the constant need for the choke is an indication of a poorly tuned engine. I've owned multiple carb engines and I've never needed this much choke. Heck I don't even know where the choke on my lawnmower is lol!

[mrgz250]

1st used a ngk dr9ea plug the air screw should be set about between 3 to 4 turns
if the bike has been sitting long & lots of miles on it take the carb off ck if the o ring is on the front of the manafold by the head its probley rotted out now u can take the carb apart & ck all the passages & clean it well use oem suzuki parts only mine is set at 4.5 turns
I get 85 to 100 mpg

[alantf]

use oem suzuki parts only

What a load of boll*cks!!!!!!!

[alantf]

I get 85 to 100 mpg

So does Father Christmas. :whistle:

[OldNTired]

I get 85 to 100 mpg

So does Father Christmas. :whistle:

I want to know what he uses for fuel! :)
And, what he puts in the gas tank...

[Water Warrior 2]

Genuine Suzuki gas produced in Japan.

[raul10141964]

do not trust mrgz250 he is spanning all the treads


my settings are
2.5 turns on the pilot
nedle shine
140 main jet

63 MPG
choke under 5 minutes below 60F

[Menachem]

Hey all, I'm new here, and a new rider. I have a beautiful new (used) 2005 gz250. I think I have the same question as some others...

How long does it normally take for the engine to heat up? It seems like it takes about 20 minutes from cold start, unless I jam up the choke, which I don't want to. I feel like sitting and idling for 15-20 minutes is bothering my neighbors lol.https://uploads.tapatalk-cdn.com/20180430/2a70a09003596ac5581232c1c1ddc8d5.jpg

Sent from my Pixel 2 XL using Tapatalk

[Water Warrior 2]

You should be using the choke(enrichener) to start the bike from a cold condition. Give it a couple minutes of fast idle to get the juices flowing and lightly touch the engine fins. If they are warm then just ride off with partial choke for a short while and then you are done. Two minutes of fast idle gives you time to do a safety check. All lights, brake lights with hand lever and foot lever, horn, signals, a quick glance at the chain and tires too. Then get your gear on and ride. I normally am dressed except for my helmet before firing up the bike.
And yes I am a bit of a safety nut. I can't and won't ride without a full compliment of riding gear. It is a bit of a pain now and again but I don't plan on suffering badly from even a little mishap that may occur.
I will now tell you what I tell all new riders. Get a copy of Proficient Motorcycling written by David Hough. It is the best and cheapest life insurance you can buy. A long dry read but packed with all the good stuff to stay safe on the streets.

[alantf]

My handbook (Spanish) says to leave the choke on for 30 seconds, but I know that American bikes are set up leaner than the European ones, so it may take longer. :hmm:

[Water Warrior 2]

My handbook (Spanish) says to leave the choke on for 30 seconds, but I know that American bikes are set up leaner than the European ones, so it may take longer. :hmm:

Canadian bikes are the same as European set-ups. However it all boils down to a crap shoot in the end. To many variables to make a set rule.
Is the bike outside in the sunshine and warmed up that way or parked underground and cooler? Likely every rider might have a slightly different circumstance and time will determine the best first start of the day. All part of the learning process. :ride: