DirtRider . Net MX, SX, Arena Cross, Off-Road Community
Dirt Rider . Net Text Version Home
Dirt Bike Dirt Bike Dirt Bike Dirt Bike

This is the text version of DirtRider.Net
Click Here for the Full Version


Pages: 1

how to start a four stroke

(Click here to view the original thread with full colors/images)

Posted by: thorman15---------------------

i have always been on a 2 stroke, and am thinking on getting a 4 stroke, but i have no idea on even how to start one, so do you think you guys could let me know how to start one (either a 03 yz250f, or a crf250) before i go and make a fool of myself
thanks


Posted by: biglou---------------------

There's really nothing to it these days. Both models you mention are auto decomp. Meaning, you don't have to pull a decompresion lever to kick it past TDC. Basically, kick it just like a 2-stroke. Use the choke when it's cold, and use the hot start lever when it's hot. Never touch the throttle when starting except maybe a blip or two when it's very cold out and first starting it. Good thing to do for 4-stroke newbies is to grab the front master cylinder when starting. This prevents that instinctive kick and twist motion! The modern 4-strokers have accelerator pumps which squirts a stream of fuel when the throttle is twisted. Sure fire way to either foul out or ensure another 5-10 kicks to get it to light off. The pilot circuits in these seem to be a little sensitive to colder or hotter weather, also. I usually go up one pilot jet size in the winter, and back in the summer. Adjusting the pilot screw (technically a fuel screw) by 1/2 a turn or so either way can help compensate for lesser temp changes if you start having trouble. Works for off-idle throttle response tuning as well.


Posted by: YZ165---------------------

Let me paraphrase for Lou,..... Kick it.


Posted by: slodsm---------------------

I have noticed when it is cold, My crf has to have two small blips of the throttle or it will take forever. With two blips it's two kicks and she is ready to roll. When it's hot, pull the hot start and one small blip the first kick and she starts every time. It took me a bit to get used to it coming from a two smoke but once I got over the fear of flooding it by touching the throttle, it starts like a champ now.


Posted by: Treejumper---------------------

Quote:
Originally Posted by slodsm
I have noticed when it is cold, My crf has to have two small blips of the throttle or it will take forever. With two blips it's two kicks and she is ready to roll.


My 450 is the same way. If it sits longer than 15 minutes i have to crack the throttle 2 or 3 times and it fires on the first kick. If i dont i sit there kicking til i crack the gas. My buddies is the exact opposite. If he even touches the throttle he has to kick forever.


Posted by: buck_y_lee---------------------

Must it always be a 'hot start' or a 'cold start'? What if she's been running for a minute and for whatever reason shut down - do I go for the choke, the lean knob or can I kick her at standard mix, maybe a little squirt of throttle?

BTW, I'm finding the YZF to be a dream to start. Just gotta put your weight into the full stroke and she'll go first kick.


Posted by: biglou---------------------

That's the way mine always are-Choke when cold, hot start when hot, neither when warm.


Posted by: Treejumper---------------------

mine only needs the choke to start if its below 50 degrees.


Posted by: buck_y_lee---------------------

Thanks lads.


Posted by: Britt Boyette---------------------

I can't give you any tips. I can tell you of an observation I made the other night while watching the local Arena Cross races. Over the course of the night, more than a few people killed their 4 stroke bikes for various reason and most of them seemed to have trouble restarting thier bikes with a few of them being lapped before finding the fire. The exception to the rule was a fellow with a Husky TC450. He got behind another rider who stalled right in front of him causing him to bump his front tire into the other bikes back tire, which resulted in him stalling his Husky. The Husky fired right back up and never lost a postion and ended up second in that race. Electric starters are now considered the coolest item in the world on my list and that incident made me consider looking at the Husky line a little closer.

Britt


Posted by: Okiewan---------------------

Never had any problems starting my YZF or CRF ... hot, cold, crashed... go figure. If it sits for a few days, blip it twice.

I take that back, I kicked the crap out of the CRF at DW 03 ... helps if it has gas in the tank.


Posted by: bsmith---------------------

I can't believe nobody has posted the true way to start a real 4 stoke!!
e, or E, and/or Magic Button AKA Electric Start

Also stay far away from the YZ400, hardest starting bike I have ever been around. Cold it doesn't start, warm it doesn't start, wind blows from the east it won't start


Posted by: YZ250Fone---------------------

hahahahahha
so it would start if wind is blowing west?


Posted by: Treejumper---------------------

Quote:
Originally Posted by YZ250Fone
hahahahahha
so it would start if wind is blowing west?


Only if you stand on 1 foot and lean the the east while kicking.


Posted by: XRpredator---------------------

Now Lou said "kick it like a 2 stroke" -- that is a fallacy. When you kick it, make sure you have the starter all the way up and give it a healthy boot all the way through. If it doesn't light, dont' just kickkickkick, bring it all the way back up, take a breath, and give it another healthy kick all the way through.

A lot of the problems the pro's have (and the not-so-pros) is that they get excited when they go down and just try to kick fast, rather than kick well.


Posted by: biglou---------------------

Not true pred. The 450 with the auto decomp likes short, stabbing kicks. If I go to TDC, give full, through kick, I'll be there kicking all day.


Posted by: BSWIFT---------------------

Quote:
Originally Posted by biglou
Not true pred. The 450 with the auto decomp likes short, stabbing kicks. If I go to TDC, give full, through kick, I'll be there kicking all day.

You said it, brother.


Posted by: Dirt Bike Dan---------------------

Well you see, the whole four-stroke starting problem is all in the spark plug. Simply unsrew the plug, then screw it into a two-stroke

seriously though, I couldn't imagine what it is like trying to light a 450, or worse, an old 5 or 600 single.


Posted by: twoofeach---------------------

[QUOTE=Okiewan]Never had any problems starting my YZF or CRF ... hot, cold, crashed... go figure. If it sits for a few days, blip it twice.
QUOTE]

First post so, I'll make it a good one.

I have a 2000 YZ426. At first it was a chore to start, or not to start. I installed an '03 YZ450 exhaust cam with the auto decompression and now it's sooo easy. I can't flood it. Twist that baby and VROOOOOOM! Hot, cold, warm, lukewarm, dumped, it's all good. I even crashed recently (totally on it's side) and it stayed ON. Yeah, I almost crashed again after getting back on from being shocked. After you master kicking one of these babies, everything else seem easy. The bikes with no autodecompression, you just have to feel for the "sweet spot" with the piston at TDC and pray the planets are aligned just right.


Posted by: strech---------------------

when you stand on the kick start , make sure when you push down you dont open the throttle.
For practice put your right hand on the handle bar close to the throttle.
This will stop you putting unwanted fuel in to the carb , which should make it easy to start hot or cold.
Me i would stay with the 2 stroke


Posted by: MrLuckey---------------------

Quote:
Originally Posted by twoofeach
The bikes with no autodecompression, you just have to feel for the "sweet spot" with the piston at TDC and pray the planets are aligned just right.


Unless it's a KTM, then you just kick it and never touch the decomp lever.


Posted by: zio---------------------

Quote:
Originally Posted by biglou
Not true pred.


Lou just called Pred ugly & stupid.


Posted by: Jaybird---------------------

I found that after installing the auto-decomp. cam, I can light up the 444f with my hand, (if I wanna).

Using my leg, a short lil stab gets it going in just about any weather.


Posted by: Zoomer---------------------

Jay, that bike always started easy!

Like all of them, you have to have them jetted correct, and then learn each ones special way, and they all start (almost all) pretty easy. Its more technique then anything. The auto compression release cams do make things easier.

My new ride (since the 444) almost always starts in less then 1 kick. I use to stop guys on the track just to show them how easy it would start


Posted by: Zoomer---------------------

[QUOTE=Jaybird]I found that after installing the auto-decomp. cam, I can light up the 444f with my hand, (if I wanna).QUOTE]

I found after installing the Auto-kickstart button, I can light up the 525 with my little finger


Posted by: wayneo426---------------------

I think Im just gonna have to buy something with a button.


Posted by: Jaybird---------------------


It's all good!


Posted by: Shig---------------------

My 450 likes a lazy 1/2 kick, but I might have to fly Lou out here to get my boss's friggen CRF 250 started. Its brand new, but I'm thinking that the dealership might have put some low-octane gas in it. My old DR 650 was nearly impossible to start on anything less than premium gas. On the 250F we've tried jetting and every technique posted, but it won't fire from kicking. After bump-starting, it starts easily in a kick or two.



Text Version Home





vBulletin Copyright ©2000 - 2009, Jelsoft Enterprises Limited.
vB Easy Archive Final ©2000 - 2009 - Created by Stefan "Xenon" Kaeser