Big red 250es starting/running troubles

[SuperRed]

Bought a 250es big red in December and have had starting problems since the start, guy said it ran. Didn't fire up when I got there. Warmed it up in a garage and tinkered with the carb,spark plug and such. Finally started up perfect. For three days I would just have to wire brush the spark plug before firing it up. Then the fourth day wouldn't start. For a while so we played with carb again and then sometimes ran but with a noticeable loss of power. Then took it hunting and at one point progressively started reving very high while parked until I turned it off. Then would drive for a bit but then die while I'm driving it. So I finally took it to a mechanic and he took apart/cleaned the carb and installed a new carb kit. He said it still ran rich but did run. When I picked it up it was to cold to start but warmed it in the garage and started right up. Hour later in maybe -25C started but wouldn't hold an idle just stalled when I let off. Then wouldn't start. Next day maybe -5C started after trial and error for 10minutes, finally and was riding it around. It would die but hardly touching the starter would fire up, Then suddenly died and wouldn't turn back on. Then for 2 days wouldn't. If it did it would be for 5 seconds and shut off. After I left it for 5 min. Today +8 same thing. So I bought a new spark plug. And it lit right up first try let it idle for a couple minutes. Turning the knob in the carb tO see if there was a difference cause it was idling high. Then came to slow normal idle. Let it run for 2 min then suddenly shut off. Started up about 3 times but would die right away. Now won't start up.... Again. Please help, my first (toy) and I just wanna ride it is that so much to ask? Thanks for reading any suggestions would be greatly appreciated.

[dougspcs]

Going out on a limb to guess you have the 85 BR. Since that model has a poorly designed fuel enrichment circuit(choke) they are a real bltch to start below 0'c..no matter how cleaned or tuned!!

But that being said, have you checked and cleaned the tank and petcock?? Since a small amount of rust or tank sediment could quickly baff any attempts to clean the carb since this machine lacks a fuel filter. All it has is a screen in the petcock..

Sounds like time for a 'do-over' on the carb work. Secondly there is a choke circuit fix to deal with the cold starting problem..or just message 'FlyingJ' and arrange to send the carb to him for a PROPER rebuild!! Best money I ever spent!!

Then the tank/petcock cleaning with fresh gas..install a small inline fuel filter. Then install another new plug. Any plug that has been fuel soaked will never be right. For $3, replace it..

Do all this and my bet would be you'll never have to screw around with it again!!

[tri again]

x2 what dougs said.
I have a few of those and refuse to accept anything but perfection from them.
Instant starts etc.
How long does it sit before you restart it?
MAYbe simple as fuel tank vent.
Does it seem to be a 'hot' run issue or will it die and restart when coldish?
If hot start/run, I'd hit various components one at a time with a hair dryer until it dies.

The overrev while idle is odd.
Let me read it again but we absolutely MUST get you running correctly.

When I get cornered, I'll read everything the search key has to offer, even if it's not the machine I'm working on.

[tri again]

Odd hi rev sounds like an air leak. but it's also not consistent. right?
Does it have spark when it dies?
I've fixed psycho intermittent problems by nipping the last bit off the plug wire so the plug cap has fresh copper to screw into. Fast and free to do.
Best place for me to start is usually the 'hard' part stuff like valve adjust / timing as any other adjustments are somewhat futile imo.

The factory sanctioned 'wiggle test'? ( a Ford procedure) checking all electrical connections?
Not fun, I know.
Cheap multimeter and test electrical components?
Can you click on:
service manual
?
It has all the specs and procedures.

[tri again]

I get logged off, hence the multi replies.
There is a thread titled 88 big red recently.
May be a difference between electric start and kick start.
I have an 87 that will not e start but WILL kick start in 1/2 kick.

We'll get you running.
and you say it sounds great and runs lovely when it decides to behave?
No timing chain slap or valve tick or other noise?

[tri again]

..and once again, does it have spark when it dies and refuses to start?

[Trimoto74]

I know my way around a carb pretty good, but I took mine to a guy who pulls them apart every day. Best $35 I've spent. Starts like nobody's business and purrs like a kitten. Was experiencing similar issues to yours.

[SuperRed]

Going out on a limb to guess you have the 85 BR. Since that model has a poorly designed fuel enrichment circuit(choke) they are a real bltch to start below 0'c..no matter how cleaned or tuned!!

But that being said, have you checked and cleaned the tank and petcock?? Since a small amount of rust or tank sediment could quickly baff any attempts to clean the carb since this machine lacks a fuel filter. All it has is a screen in the petcock..

Sounds like time for a 'do-over' on the carb work. Secondly there is a choke circuit fix to deal with the cold starting problem..or just message 'FlyingJ' and arrange to send the carb to him for a PROPER rebuild!! Best money I ever spent!!

Then the tank/petcock cleaning with fresh gas..install a small inline fuel filter. Then install another new plug. Any plug that has been fuel soaked will never be right. For $3, replace it..

Do all this and my bet would be you'll never have to screw around with it again!!


No I have not cleaned the tank/petcock and yes it's an 85. How do I get the choke circuit fix? And suggestions for the fuel filter? I know I really want to send it to (I thought his name was flyingW?) but the mechanic said he would fix it, if he doesn't which he better but He just thinks it needs smaller jets because it's running to rich and keeps fouling the plug. Then I think it's flooding and that's why I have to wait. But I will clean the tank and not sure about the petcock but I will look it up. Tank has lots of inner rust and sediment

[SuperRed]

When it stalls it makes a loud bad sound in noise might just be it stalling though. This is when it's coldish. Yesterday it was +8C and nothing till the new plug. It only revved really high one time wage I was hunting. Only time I've driven it that much so the warmest it's ever been. Didn't check if it sparked after it wouldn't start. Will do that tomorrow. Got off too late

[dougspcs]

Here is a very detailed thread on the complete and extremely thorough method that FlyingW (my bad on the name )uses to rebuild his carbs..if your mechanic is skilled he should have no trouble following it. Included in this thread is the 'cold start fix' instructions..a properly cleaned carb is vital to your issues..

http://www.3wheelerworld.com/showthread.php/161746-ES-SX-350X-Carb-rebuild-Tutoral

Next with the tank and petcock, drain and flush it..then blow it out to clean as much of the small particles as possible. Then open the petcock on the bottom of the tank and clean it as well. There are numerous threads in here on how to remove the rust and coat the tank if you choose.

The fuel filter thing should be simple..any small inline fuel filter that you might find on the shelf at your local auto parts store should be good. Just splice it into the fuel line to stop the particles from getting into your carb..if you don't do anything to deal with the tank then change the filter every year at least to keep the ongoing rust from getting to the carb or plugging the filter up. I have a beater trike I did this with and even removed the screen from the petcock to prevent it plugging in the future..I just change the inline filter every spring and keep the tank full of gas all the time to slow the rust. Air in the tank is the enemy!!

[tri again]

Rusty tanks never rest.
I just hate fighting with them so it's either pressure washer
or radiator shop for mine. Don't really care what they look like inside as long as they don't leak and / or throw any more rust particles, altho silver grey factory inside is always a dream.
Dry it with heet and heat.
and keep it full.
No air no rust.
Much easier than cleaning a carb multiple times for no real good reason imo.

Absolute dream machines when they run right and dependably.

[SuperRed]

Ok so the new plug DOES give off a good spark but it still will not start at all now. Going to bring it back to the mechanic so he can change the jets to smaller ones. (He thinks that is the only problem) and when i get it back from him i will let you guys know how it went!

[SuperRed]

Sorry it took so long but just got it back from him the other day and it runs awesome. He just ordered smaller jets and re-cleaned the carb, also installed a fuel filter. Sometimes while idling for a while it will randomly stall but i think that is because the idle is very low. When at in a high gear and slow down quickly without gearing down it was also stall, it only happened once to me and once to my buddy. But gearing down progressively it keeps giving her. So that might just be how it is. Other than that shes a beaut now and i love having a 250 big red (more than my quad, which i just bought) but i want it to work perfectly like it should so i can show it off to my buddys!