Author Topic: educating my mechanic  (Read 3919 times)

Offline paretlane

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educating my mechanic
« on: January 29, 2012, 01:46:02 PM »
Hi.  You guys have been very helpful in the past.  My bike is headed to the mechanic in a week or so but I'd like to give him some ideas to look at before he starts work.  Here are my symptoms: I've managed to run out of gas before switching to reserve twice.  Both times I had to switch to prime to get it restarted. I them moved the petcock to reserve before returning to the normal setting when I filled up.  Now, after about 40 minutes or so (when the bike is fully warmed up) while in 4th gear running at about 7,000 rpms, the bike starts to feel like it's running out of gas -- when the tank still has about 2.5 - 3.0 gallons left -- and dies.  I switched to reserve, pulled the choke out and increased the idle speed.  It started up, I pulled off the highway and switched to "on" setting, pushed choke back in, and reduced idle to 2,000 rpms.  It worked fine the rest of the way home, though I pulled off the highway and took local streets back never getting above 50 mph and third gear.  The bike runs a little rich because the previous owner put in a dynojet stage one kit and hadn't gotten around to putting on a new exhaust that he'd bought.  That's one of the things I will now have taken care of but I'm a little concerned about the fueling issue and don't want my mechanic to spend hours trying to track it down if you guys have some thoughts of what he should look at first.  Thanks in advance.

Offline rider123

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Re: educating my mechanic
« Reply #1 on: January 30, 2012, 05:05:11 AM »
Could be the breather hole is gummed up. Next time it dies, open up the fuel cap. If you hear a "whoosh" or the bike starts running again normally then the breather tube is gummed up. As the tank drains it needs to have air to replace the gasoline that is used up. If the breather hole is covered or half gummed up it will not allow fuel to flow. You could try running around with the fuel cap loose to test but be carefull, don't fill the tank right up to test. If you drive around with a half a tank a gas for hours with no problems that that is most likely the case. Also see if your petcock is working correctly. You can do this the lazy way by driving around on the prime setting, just remember not to leave it on prime when parked. If it works perfectly fine for hours then probably the petcock needs rebuilding, it's not that hard if you would like to save some money doing it yourself. If you really want to test the petcock take the tank off the bike, and stick a bucket or funnel underneath to catch any fuel. Briefly put the petcock on prime, does it flow fuel? If so connect some vacuum line to the petcock and suck with the petcock on either "On" or "Reserve", fuel again should flow out. Since the bike is still flowing fuel with the RPM's fairly high on prime, I would wager either the breather hole is a little gummed or the diaphram in the petcock is tired or sticky. Both are relatively cheap fixes. In fact if the breather hole is a little gummed up all you need to do is poke it through with a coat hanger or other piece of wire to clear it out, cost: free.

As far as rebuilding the petcock, usually you can get aftermarket kits for around $30 or $40 bucks and about an hour of work including draining the fuel from your fuel tank temporarily. It's pretty easy to do if you want to save $100 in labour costs, they usually come with instructions or you can just look at a microfiche and just replace what's already in there. The bitch part is draining the tank of fuel. To solve that problem you can ride until the tank is as low as it will go then tilt the tank on its side which will allow you to take the petcock off but the little fuel in the tank won't reach as high as the fuel cap. Just make sure it stays there while you work on the petcock so it doesn't tip over and spill any fuel. If you don't want to rebuild you can buy a high quality pingel type petcock which will probably outlast the bike but they are a little pricey but on the flip side it's probably the last fuel petcock you'll buy, they come in standard sizes and usually involve an adapter plate.

http://www.pingelonline.com/powerflo.htm


Also 2000 rpm for idle is way too high, it's hard on the gears when you go from neutral to first gear, set it back to where it should be. If you have a fuel delivery problem adjusting the idle won't help your just putting extra stress on the tranny for no good reason. I have a B12 and my idle is 1200 rpm, since you either have a 250 or 400 my guess is it should be around 1500 rpm. It's good your putting on that aftermarket exhaust your losing out on alot of power without it on there. I don't understand why someone would install a jet kit without putting on an aftermarket exhaust, all your doing is making the bike super rich and LOSING power. Considering popping on an aftermarket exhaust is the easiest part of rejetting I just don't understand. That you can also do yourself if you like it's only two bolts that hold the exhaust on there, one clamp at the collector box and a bolt at the end can and thats it. Just put a coating of exhaust sealant where the mid pipe connects to the collector box and your good to go, it's like a 15 min job. If the pipe comes with a centre stand stop then it takes 20 mins.
« Last Edit: January 30, 2012, 06:09:51 AM by rider123 »
2005 Bandit 1200, Modified Holeshot Stage 1 with 17.5 pilots 2.75 turns out, and 110 mains 5 shims. Muzzy Slip on w/mid-pipe, stock filter. 1.5" hole in the airbox lid.

Offline Wrider

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Re: educating my mechanic
« Reply #2 on: January 30, 2012, 11:11:34 AM »
Stop.

Stop right now.

Don't try to "educate" your mechanic.  He does this for a living, and it is his job not only to find the problem, but to come up with a cost effective solution to said problem.  Chances are he'll look at...
1. Any in-line filter you have.
2. He'll pull the petcock to see if the filter on there is clogged up.
3. He'll go into the carbs to see if they're clogged up.

FWIW this is coming from a guy who has worked as a professional motorcycle mechanic.  I always hated when someone would try to diagnose a problem, especially because it usually meant that when I told them the actual problem, they almost always disagreed with me.

Tell him the exact symptoms like you explained them here, and let him do his job.

Offline paretlane

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Re: educating my mechanic
« Reply #3 on: January 30, 2012, 11:33:31 AM »
He's a good mechanic who rides an old Honda Nighthawk as his bike of choice so I know there isn't much on this bike that will surprise him.  I just wanted to see if anyone had had this problem before.  This week is supposed to be in the mid-60's here and I'd like to ride.  Would riding with the petcock in "prime" cause me problems later?  Would it still likely stall out?  If you guys think I should hold off on riding until the problem is solved, that's what I'll do.  Thanks for all the advice. 

Offline rider123

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Re: educating my mechanic
« Reply #4 on: January 30, 2012, 02:18:52 PM »
No it won't cause any problems but be sure to put it back to "on" when your parked. You're only putting it on "prime" for testing purposes(maybe an hour or two) I wouldn't ride permanently like that. 9 times out of 10 it usually the petcock. If you want to try the things I suggested to fix it yourself go ahead otherwise just tell the mechanic the symptoms. Personally I would try and fix it myself, the things I suggested are super easy and you would learn more about motorcycles that way. Even if you needed to re-build the petcock they aren't that hard to replace the parts inside them. What year and model is your bike? I can find you the microfiche for the petcock.

To simplify what I posted:

1. Run until it goes tits up
2. Open gas cap - start it up, does it run fine? If so it's the breather hole if not goto step 3
3. Turn bike to "prime" Does it work? Yes? then the petcock diaphram it probably dead goto step 4
4. Order rebuild kit or call mechanic.

Total time to test maybe a couple of hours. Money saved $100 or so. Learning how to fix bike problems yourself: Priceless.
« Last Edit: January 30, 2012, 02:29:00 PM by rider123 »
2005 Bandit 1200, Modified Holeshot Stage 1 with 17.5 pilots 2.75 turns out, and 110 mains 5 shims. Muzzy Slip on w/mid-pipe, stock filter. 1.5" hole in the airbox lid.

Offline paretlane

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Re: educating my mechanic
« Reply #5 on: January 30, 2012, 02:28:26 PM »
It's a 1991 B400.  I didn't see an air hole.  Instead of an air hole, it may have an air hose at the bottom of the tank.  But I don't think that's the problem.  I think it's either the petcock or a problem with one of the jets.  My most recent bikes were a lot more modern and not easy to work on without a lot of equipment (Ducati Multistrada 620, BMW F800st).  I don't ride long distances anymore so wanted something simple and fun that wouldn't depreciate much while sitting in my garage.  I love this bike.  It's perfect around town and on short day trips.  Now I just need to get it working reliably!  Thanks again.

Offline rider123

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Re: educating my mechanic
« Reply #6 on: January 30, 2012, 02:30:28 PM »
If you open the gas cap you should see the breather hole underneath where the gas cap hinges. At least thats on mine. I'll check the microfiche.
2005 Bandit 1200, Modified Holeshot Stage 1 with 17.5 pilots 2.75 turns out, and 110 mains 5 shims. Muzzy Slip on w/mid-pipe, stock filter. 1.5" hole in the airbox lid.

Offline paretlane

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Re: educating my mechanic
« Reply #7 on: January 30, 2012, 02:32:02 PM »
I looked and saw a couple of small holes, one near the top (when opened) and one near the bottom of the gas cap.  Neither seemed to go anywhere.  The bottom one just hit a piece of metal. 

Offline rider123

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Re: educating my mechanic
« Reply #8 on: January 30, 2012, 02:37:32 PM »
Thats probably it after many years you get dirt and pieces of leaves etc stuck in there, its probably fine but it would be a shame to pay money for someone just to stick a wire in there to make sure they are clear, plus the downtime of the bike. Get a piece of small wire and make sure they are clear of crap.

Here is a microfiche for your petcock from www.bikebandit.com they don't show the internals but if your really scared you can buy a whole brand new petcock from them for $92 so if any of the alternative solutions cost more than that you might as well buy a whole new petcock and pop it on there.

http://www.bikebandit.com/1991-suzuki-gsf400m-bandit/o/m6135#sch248402

I'll try and find a petcock rebuild kit for you. I know Holeshot has one but thats for the 600/1200 but I'll bet a dollar they all use the same petcock or there is a similar one on another Suzuki. I'll take a look. Try the easy shit I suggested first. If it was me after trying all the other things I would take the petcock apart and clean it and make sure the diaphram isn't sticking causing fuel delivery problems. If it all goes to hell you can get a new one for $100 and get a brand new petcock to boot which is about what you'll pay for someone to just look at it. The petcock only has two bolts so if you're good enough to take 2 bolts off you can change it yourself.
« Last Edit: January 30, 2012, 03:37:57 PM by rider123 »
2005 Bandit 1200, Modified Holeshot Stage 1 with 17.5 pilots 2.75 turns out, and 110 mains 5 shims. Muzzy Slip on w/mid-pipe, stock filter. 1.5" hole in the airbox lid.

Offline rider123

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Re: educating my mechanic
« Reply #9 on: January 30, 2012, 03:10:49 PM »
Wow finding a petcock rebuild kit for the 400 is as rare as hen's teeth. I even found a rebuild kit for my old GS400 I owned in the 80's. Anyway from what I gathered out there the DR350 uses the same petcock allegedly however there are no guarantees. You may want to try a wrecker, as you'll pick up one for half price. If your willing to pay someone to look at it you can probably afford to buy new from www.bikebandit.com which may be your best bet if you want %100 reliability. I'll keep looking.

Here is the DR350 kit if you want to take a chance:

http://www.cheapcycleparts.com/products/33182-k-l-supply-18-2730-fuel-air-other-k-l-fuel-petcock-repair-kit

The hose at the bottom of the tank is probably the overflow hose it doesn't affect anything to do with fuel delivery. As I said if you have done the tests and think the petcock is screwy you can always take it apart and clean it out, will probably be just fine after that. Just watch out for the spring on the diaphram, don't lose it!
« Last Edit: January 30, 2012, 06:58:54 PM by rider123 »
2005 Bandit 1200, Modified Holeshot Stage 1 with 17.5 pilots 2.75 turns out, and 110 mains 5 shims. Muzzy Slip on w/mid-pipe, stock filter. 1.5" hole in the airbox lid.

Offline paretlane

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Re: educating my mechanic
« Reply #10 on: January 30, 2012, 03:12:00 PM »
Thanks!

Offline rider123

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Re: educating my mechanic
« Reply #11 on: January 30, 2012, 07:00:59 PM »
Here is the microfiche for your bike here on the forums be worth a download.

http://forums.banditalley.net/index.php?action=tpmod;dl=get64

« Last Edit: January 30, 2012, 07:02:58 PM by rider123 »
2005 Bandit 1200, Modified Holeshot Stage 1 with 17.5 pilots 2.75 turns out, and 110 mains 5 shims. Muzzy Slip on w/mid-pipe, stock filter. 1.5" hole in the airbox lid.

Offline interfuse

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Re: educating my mechanic
« Reply #12 on: January 31, 2012, 08:41:03 AM »
The bandit 400 petcock isn't rebuildable. You can't take it apart.
Mike

'91 GSF400
It's more fun to ride a slow bike fast than a fast bike slow.

Offline rider123

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Re: educating my mechanic
« Reply #13 on: January 31, 2012, 08:53:48 AM »
You mean its press fitted together? You can't even take the screen off it and get to the internals that way? Thats cheezy! Even my Bandit 1200, the petcock, which looks a little cheesy is rebuildable. What does Suzuki suggest you do when it dies? Start walking? If it was put together it should theoretically be taken apart. Although I guess he did get 20 years out of the old one, maybe buying a pingel may make more sense. I've had like 10 bikes dating from the 70's era until now and they all had petcocks that could be taken apart to at least clean them. Even my lowly GS400 petcock could be taken apart because I did it to clean it out when I bought the bike to get the shit out of it, was all gummy before and after worked like a champ with all the rust flecks and dead gas varnish out of it.

Are you sure it can't be taken apart? The microfiche looks like there is a philips screw on the fuel selector side. What about on the diaphram side of the petcock? I'm assuming the petcock wasn't grown in a Petri dish. If not the only option is to buy a whole new petcock, oh well at least the options are getting easier and he can pop it on himself. Or another option is to take off the petcock and spray some carb cleaner in the reserve and main feed tubes and rotate the petcock handle to work in the carb cleaner and maybe free it up if it's sticky.
« Last Edit: January 31, 2012, 09:29:33 AM by rider123 »
2005 Bandit 1200, Modified Holeshot Stage 1 with 17.5 pilots 2.75 turns out, and 110 mains 5 shims. Muzzy Slip on w/mid-pipe, stock filter. 1.5" hole in the airbox lid.

Offline interfuse

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Re: educating my mechanic
« Reply #14 on: January 31, 2012, 05:36:59 PM »
You can remove the valve and clean it but you can't get to the diaphragm which is the part that usually fails. When the petcock fails, it fails open... so suzuki would recommend you change your oil. Next time mine goes I'm switching to a pingel.
Mike

'91 GSF400
It's more fun to ride a slow bike fast than a fast bike slow.