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Posted

Been chasing a problem for awhile with my 97 Bandit 1200.  I bought it used with only 12000 kms on it -- less than 9000 miles.  It was a salvage bike with minimal cosmetic damage.  I since rebuilt it to look like an Endurance Racer from the 70s.  I had it running briefly before the rebuild started, but shut it down as the float bowls were leaking and the petcock was not working properly.  Since the winter, I've added a Holeshot Stage 2 and Pods.  I had to remove the stock airbox due to the frame mods.  The bike has the following mods:

Blackwidow header, GPR exhaust, engine otherwise stock.  With such low mileage its just due now for a valve check, but that can't be the issue, right?

I've got a constant state of generally poor running in all rev ranges, and constantly foul plugs (sooty, not wet).  I've done the usual:

- installed new K&L float valve kit to stop the flooding

- new Pingel petcock

- Li-Ion battery (8 cell -- the recommended size for this project)

- set float height to 15mm (tried 14, 16, and even 17mm with no improvements)

- checked spark -- good (replaced plugs 3x as they get sooted up) -- although nothing to compare it to -- a decent blue-white spark as I crank the engine over.

- fitted new stainless emulsion tubes from Factory Pro (no improvement)

- tried every different jetting combination, fuel screw, pilot jet, needle clip position possible (all done in one-step increments)

- as the bike is revved, it blows black smoke out the tail pipe (yep, rich)

- as I powdercoated the frame I made sure the engine was making good ground and added a ground strap to ensure I had a good spark; removed powder where the engine and any ground (including the coils) contact the frame.  I also cut 1cm off the ends of the HT leads and put them back into the plug caps. I originally thought it might be a weak spark problem (all 4 plugs look the same).

- checked the inlet boots to ensure there are no cracks.  Resealed the o-rings with Yamabond to make sure it wasn't leaking there.

Currently it has the smaller pilots with the fuel screw at 2.5 out.  147.5 main.  Needle at 3rd clip with the spacer.  Steady throttle bucking and popping on the highway, gets worse as the bike runs longer and the plugs foul up.

I've never been so flummoxed before in my 20+ years of bike building.  My friend with a say what now!? 1100 had pods and a pipe and it runs perfectly, with over 50,000 miles on it.  Unfortunately he lives in BC and can't lend me a set!  Any ideas on what to do/try next?  There might be a racer buddy with a set of say what now!? 1100 carbs (no idea of what model year or size) I could try... he only lives a few hours away...  I'm pretty proud of my pretty bike but am pissed that it doesnt run worth a damn.  I'm wondering yet again about an electrical issue?

done1.jpg

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Posted
1 hour ago, riversbikes said:

- installed new K&L float valve kit to stop the flooding

does this include the O-rings around the valve bodies? They could be leaking and letting fuel through.

Nice Bandit by the way.

Posted

Yep, those were originally faulty and new ones installed.  Just checked the coil resistances as per the manual.  Primary at 2.6 on each side (specs 2-4) and within the HT leads themselves, 39 (spec is 30-40).  Don't think its electrical...

 

Posted

147.5 on the mains sound humongous - not right at all. Std Bindit is something around 105 from memory - I only needed 136's in a fairly full on 1186 GSXR with 36mm CV's and pods. I know a lot of peeps don't like DJ kits ...... but all the ones i've used have been pretty well right out of the box with only a little dyno work to refine!

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Posted

Checked again, air intake for pilot jet (at the front of the carb) on cylinders 2 and 4 were restricted, but not plugged.  Cleaned the carbs again and will try tomorrow.

 

Posted

If it's a salvage bike it may have been stood some time. Have you tried giving the carbs a quick bath in an ultrasonic tank ?

They may look cleans but you can't see or clean out all the passages you can't get to.

Posted

Have you checked all of the wiring connections relevant to the ignition system? I had a similar problem with my EFE engined bike and the problem dissapperead when I went over every ignition connection. Even when block connectors appear tight they may not be, especially if they plug directly into components like CDI boxes. A big problem here is so many things have been changed all at once so it is very difficult to begin to identify from where the problem lies.

Posted

Ive always found jet kits supply way too big jets And the needles virtually pointless as are the air correctors/drilling the slides.

You can get just as good a setup ysing standard needles and jetting to suit. I also would never expect anything to be plug and play. Always use a dyno for setup.

Personally I would ditch the jet kit. Go back to stock needles and stick some 120 mains in. Shouldnt be far off at that I wouldnt think on a stock motor. Then get it on a dyno

Posted

You guys might be on to something here --- went back to all stock, but with the Holeshot supplied pilot jet (35).  I tried the stock needle at 1 clip then 2 clips richer (down to the richest possible), but wouldn't rev at all.  Less/little black smoke!  Put the HS needles in on the leanest setting.  Screws now 3.5 turns out.  Even better.  Took it for a short spin, and understandably wouldn't take anything past 1/2 throttle with the 102.5 mains.  Will go to the bike shop and see if they have any... 120s to start.  Now that everything is FI, my local shop isnt stocking many mains anymore, may have to order some in.  Should I try something smaller?  115s first?

 

Posted
3 hours ago, riversbikes said:

You guys might be on to something here --- went back to all stock, but with the Holeshot supplied pilot jet (35).  I tried the stock needle at 1 clip then 2 clips richer (down to the richest possible), but wouldn't rev at all.  Less/little black smoke!  Put the HS needles in on the leanest setting.  Screws now 3.5 turns out.  Even better.  Took it for a short spin, and understandably wouldn't take anything past 1/2 throttle with the 102.5 mains.  Will go to the bike shop and see if they have any... 120s to start.  Now that everything is FI, my local shop isnt stocking many mains anymore, may have to order some in.  Should I try something smaller?  115s first?

 

You can get jets for bandits on eblag in virtually any size. Theres a seller that does 5 for £10 worth getting a few sizes

Posted

Ive had a couple of bandit 1200's . a standard engine with k and n filters and a race can will generally run with std carbs with 10% increase, not perfect mabey but some where handy, your jets are wayyyyy to big 102.5 standard plus 10% = 112ish mains, plus a bit for the down pipes, 115 -120 at the most, Then go to a dyno and save yourself loads of time and money:tu:tu

Posted

Ordered a set of 115 and 120 from the local bike shop... he had 1 120 in stock, nothing else.  This experience makes me wonder about the logic of Holeshot's kit, which everyone raves about -- the smallest jet included is a 147.5.

Posted
4 minutes ago, riversbikes said:

  This experience makes me wonder about the logic of Holeshot's kit, which everyone raves about -- the smallest jet included is a 147.5.

most people haven't got a fooking clue what they're talking about....

Posted
3 minutes ago, vizman said:

most people haven't got a fooking clue what they're talking about....

obviously i'm not including (all) the fine upstanding oss forum users in that frivolous statement.

Posted
5 minutes ago, vizman said:

117, b12 chop, pod filters and akro system.

Dunno why but that sounds like a recent takeaway delivery order. Think I had crispy duck too.

Back on topic I've found jet kits to come with stoopidly big mains too.  Mmm... big main courses.

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