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Post by mattb on Jan 20, 2008 21:50:50 GMT -5
I was talking to my local grocer, who is also a drag car mechanic and has watched me kicking my bike over a few times to get her started. He told me about a mod they do on the cars, that might make starting easier on the SR. Basically, just fitting a valve to the intake manifold rubber (carb joint on the engine side) through which one could pump a small amount of petrol or something like aerostart to enter the space, with the engine's intake valve open. Is this what our hot start button does anyway? Even if it is, would such a device, pumping aerostart, make a different? Thought I could get a new manifold rubber and experiement. Obviously it would have to be otherwise air-tight.
My bike starts first kick when she's cold, but can be up to four kicks frequently enough after riding, which is not so good for my sensitive back.
Matt
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Post by wotavidone on Jan 21, 2008 0:00:51 GMT -5
The hot-start button cracks the throttle open - about 1mm on my bike.
Personally, there is no way I would give my baby a dose of aerostart, or other ether based nasty stuff. I have always regarded aerostart as the very last resort for starting an engine.
Can't see it being good for the engine, I visualise you are likely to get some nasty kick backs, since ether ignites at the slightest spark, and who knows what a misdirected spray would do to your paint.
Drag cars get pulled to bits every few races - they'd be lucky to put 10 or 20 miles on between pull downs.
Bugger that - spend a bit more time on getting your starting routine down pat.
Mick
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Post by miker on Jan 21, 2008 11:05:12 GMT -5
Maybe the accelerator pump in the carb would help ya - would a couple of twists prior to kicking "preload" some mixture?
miker
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Post by bigshingle on Jan 21, 2008 13:16:48 GMT -5
I think Stopusingmyname Carl (on the alarm thread) may be on to something. If SR-500s could be made easy to start probably a lot more would get stolen. So there's an upside to having to kick the crap out of a bike in public places until any thieves standing around lose interest.
Night before last I was talking to Stephen Pate at Restoration Werks and the subject of SR-500 starting came up — isn't that always one of the first things to come up?
For starting a hot SR he suggested trying an easy "priming" kick to pull fuel into the cylinder and then giving it a good, second kick with the throttle closed (or with the hot-start button on.) The existence of a hot-start button in itself shows Yamaha was trying to deal with a starting problem.
The subject of starting an SR came up because I mentioned SR-400s seem to start readily on the first kick. The Aussies around here have plenty of experience with both 400s and 500s — so is that true? Do the 400s start easier?
Could that be because the 400s have the same flywheel as the 500s, which carries the smaller-bore engine through better? (Pate suggested that idea.)
There's got to be a simple reason for the starting difficulty — although if there was a simple cure Yamaha probably would have found it.
I'm glad you brought this up Miker, because tempermental starting seems to be what most riders believe to be the main fault with SRs.
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Post by bigshingle on Jan 21, 2008 13:39:57 GMT -5
Sorry mattb — of course you're the one to bring this up. The other day Miker and I had a talk about how SRs can be hard to start, and that's what I was thinking about.
But yeah, I'm glad you brought this up mattb.
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Post by miker on Jan 23, 2008 10:40:24 GMT -5
It seems to me that that the problem Yamaha was trying to solve had to be flooding while hot, because all the hot start button does is open the throttle slightly so you can start it without touching the twist grip and making the accel pump do its thing. When mine is hot I just open the throttle slightly with the twist grip and hold it there, i.e. I'm sure to NOT move it around so the accel pump isn't operated. But I'll still seem to be flooded at times, and have to hold the throttle open while kicking to clear it out.
Now, a bike that needs priming when hot is the opposite extreme. That's why I would suggest trying a couple throttle twists to prime it. But I think that's unusual for SR's.
miker
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Post by marlon on Feb 6, 2008 12:44:04 GMT -5
Bigshingle, I've got a 400 and it's an absolute breeze to start - 1st kick 99% of the time. I always just thought that it was a old v. new thing, but maybe your mate is onto something.
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Post by mattb on Feb 7, 2008 4:27:36 GMT -5
I've got a 400 and it's an absolute breeze to start - 1st kick 99% of the time. Not only that, but you kick it on its side stand! - Mine has to be on the centre stand, with my full weight behind the kick, or forget it! |
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Post by marlon on Feb 7, 2008 7:54:06 GMT -5
Easy as all hell eh mate? Even did with my hand pretty easily the other day. (There's a bloke who does it with a 500 on youtube = Alphamale)
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Post by wotavidone on Feb 7, 2008 16:52:48 GMT -5
Mate of mine had an XT500 back when they was new.
He tells me that if the beast did not start on the first kick when it was hot, it was probably flooded. The cure was to give it two full kicks while holding the decompression lever in. After that a standard "ease it just over compression with the decomp lever, then get the kick starter back up for a full bite and give it a decent boot" would start it every time.
I've tried it, and it works.
I stop at the paper shop on the way home from work. If the bike doesn't start first two kicks, then the two clearing kicks with the lever pulled in definitely do the job.
Mick
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Post by aero on Feb 7, 2008 17:35:36 GMT -5
Mmmm 'aerostart valve?' What you really mean is a plunger that pumps neat fuel into the inlet tract? This works on 4.5 liter aero engines (thats fairly small for a light aircraft) where 2 magnetos are trying to light fuel inside a six inch inch bore.
There's a whole time and space thing going on that you'll never see on an SR 500. Max chat on one of these is 2,800 RPM or there abouts. And having had to deal with several aircraft engine fires on start up I wouldn't feel happy about pumping fuel into something 4 inches below where my knackers would be when I'm trying to start the thing.
Trust me I've started Merlin engines, extra fuel is scarey.
The best way to get good starting is fit a Mikunki VM 34 or 36. Here's the vid of me starting an SR with a VM34 carb fitted, It's so easy...so fcuking easy! yeah!
<embed width="440" height="380" type="application/x-shockwave-flash" src="http://v3.tinypic.com/player.swf?file=bi48ll&s=3"></embed>
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