help me troubleshoot my Storm

[Kurt999]

bloody hell, what have I done??

I only mentioned topics lols

[lumpyv]

'Carb fart' - quite normal but that one in the vid is doing it a bit more than usual.

yeah , mines done that for the last 5 years. does it need mending ??

[Kurt999]

'Carb fart' - quite normal but that one in the vid is doing it a bit more than usual.

yeah , mines done that for the last 5 years. does it need mending ??

Everything I've read suggests checking the valve clearances, cleaning and balancing the carbs, setting the TPS to 500 ohms, setting the pilot screws, and if it still does it then live with it.

[VTRDark]

It's a good habit to check timing and valve clearances before doing the carbs if it's not been done. Otherwise one ends up having to dial the carbs in again if it's done at a later date. It's the right order to do things in!

The most important things I have found that helps cure the carb fart is the TPS and a carb balance as well as making sure the mixture is right. This is as long as the jetting is already good and your not running too lean. One will get the odd fart now and again if jetting is right on the borderline, then as weather changes there is the odd fart caused by being a bit lean.

(:-})

[Kurt999]

So near yet so far...

The good...bike ticks over, revs freely, no leaks, sounds sweet. TPS at 506 ohms, carbs balanced, new battery, new r/r. Tested charging system all ok

The bad...on test ride its like a bucking bronco. One cylinder chopping in and out.

Pulled the plugs, rear plug nice and tan colour, front plug sooty black and dry. 48 pilots, 2 turns out front and rear, standard needles, slides/diaphrams good, 178/180 mains, oem air filter, stock exhaust. New float valves, floats not punctured.

Checked for spark on both cylinders

Is it possible for the front coil to be breaking down under load and causing these symptoms?

I'll try and switch the coils round tomorrow and see if I can move the fault to the rear cylinder

[Pete.L]

Is it possible for the front coil to be breaking down under load and causing these symptoms?

Very Possible. I seem to remember quite a few ignition packs being killed by folk unscrewing their plugs and testing the spark on the side of the engine.
Before you do swap them over have one last look at the front choke cable and make sure the plunger is seated fully in the front carb, just in-case it's sticking.

Good luck
Pete.l

[Kurt999]

Is it possible for the front coil to be breaking down under load and causing these symptoms?

Very Possible. I seem to remember quite a few ignition packs being killed by folk unscrewing their plugs and testing the spark on the side of the engine.
Before you do swap them over have one last look at the front choke cable and make sure the plunger is seated fully in the front carb, just in-case it's sticking.

Good luck
Pete.l

Ok thanks...carbs have been off about 5 times now and the choke cable is silky silky smooth. Both plungers moving freely.

Strangely the Honda manual recommends checking for a spark in this way!

Anyway moving on, having pulled the plugs after the test ride the rear plug came out looking quite lean and the front one came out sooty black...I may have already said that. So this morning I cleaned the plugs with contact cleaner and switched the coils from front to back. Stupidly I switched the plugs too, but they were new yesterday and looked almost identical once cleaned.

The bike started and ticked over but occasionally seemed to drop revs and then come back up -not carb farting actually cutting out and dropping onto one cylinder for a few seconds. Again the test ride was a bucking bronco affair, much worse than before. Only managed about 400 yards

Pulling the plugs again revealed that the front plug was now burning lean and the rear was wet with fuel and did not look like it had been firing at all (although it obviously had at idle.)

The problem appears to have moved with the coil and plug assembly so I'm going to try and source a good coil for elimination purposes if nothing else.

Once I can get it firing properly I can sort out the fuel mix

[Pete.L]

The problem appears to have moved with the coil and plug assembly

Excellent! Hopefully you are finally on your way to sorting it

Pete.l

[Kurt999]

I really hope so!!!

[Kurt999]

OK folks, we have a winner!!!!

Intermittantly faulty ignition coil.

Got a replacement today, and have ridden about 20 miles with no popping backfiring stalling or other bad behaviour! Feels a little flat at low revs-pulling away and out of tight second gear turns, but clears over 3000rpm and pulls well up to the redline. Sooo much better than before. I see a little pilot screw adjustment in my future.

Regarding pilot screw adjustment is the following right?

1/ set each screw about 2 turns out
2/ warm up the bike
3/ set idle to 1200rpm
4/ adjust front screw for highest idle
5/ adjust rear screw for highest idle
6/ reset idle to 1200rpm
7/ turn front screw an additional 1 turn out from step 4
8/ turn rear screw an additional 1 1/4 turns out from step 5
9/ reset idle to 1200rpm

Thanks

[VTRDark]

Good news on the coil.

Regarding pilot screw adjustment is the following right?

What you have there makes no sense to me, setting to highest idle and then richening it up more! Maybe if it was an air screw (two stroke) that may work but not with a fuel screw. Opening the screw allows more fuel ie a richer mix.

I set my a/f by ear. Pick a starting point, two turns would be ok for that. Then turn the screw out until you hear the revs drop, then turn the screw in until you hear the revs drop. You want to set you a/f in the middle between these two points. The tricky bit is being able to count (Keep track of) your turns. Also being able to hear the revs drop as it can be a subtle change in exhaust/engine note, so I usually keep my idle as low as I can before it cuts out. Once I have found the point in the middle turn the idle back up and tweak things from there. I also verify that it is right by monitoring the way the rev needle moves and drops back down to idle.

(:-})

[Kurt999]

Good news on the coil.

Regarding pilot screw adjustment is the following right?

What you have there makes no sense to me, setting to highest idle and then richening it up more! Maybe if it was an air screw (two stroke) that may work but not with a fuel screw. Opening the screw allows more fuel ie a richer mix.

I set my a/f by ear. Pick a starting point, two turns would be ok for that. Then turn the screw out until you hear the revs drop, then turn the screw in until you hear the revs drop. You want to set you a/f in the middle between these two points. The tricky bit is being able to count (Keep track of) your turns. Also being able to hear the revs drop as it can be a subtle change in exhaust/engine note, so I usually keep my idle as low as I can before it cuts out. Once I have found the point in the middle turn the idle back up and tweak things from there. I also verify that it is right by monitoring the way the rev needle moves and drops back down to idle.

(:-})

Makes no sense to me either, but that is what the Honda OEM manual states (page 5-18). Like you, I would find the lean and rich points where the revs drop and set at the midpoint between the 2. I thought I was missing something that you guys would know about.

thanks (again)

[Kurt999]

Still not right....obviously now firing on 2, much better and rideable in the mid and upper rev range but still overfuelling at the bottom end and not really responsive to pilot screw changes, particularly on the front carb. Riding at 80mph on the motorway I could actually feel ther motor becoming less responsive to small throttle changes which would clear with a few good revs to clear it. I'd forgotten about seeing the pool of fuel on top of the inlet valve when I pulled the carbs a few times ago.

As luck would have it i jumped the gun a bit a little while ago and bought a set of carbs for the TPS. I cleaned those up last night and bolted them on this morning.

Bike fired right up and runs like a good 'un. Pulls from very low down, right up to the limiter, no flat spots, no surging, no backfiring.

So I definately have a fault on the original carbs which I'd like to fix as they are cosmetically much nicer than the ones I put on. Given that I've replaced the float valves and cleaned all the passageways in the carbs with carb cleaner and compressed air what else could be wrong? There's a vacuum valve on the side of each carb...what do these do and could a faulty one at the front cause my problems?

Would the overfuelling have put extra load on the coil and caused it to fail...seems strange that the front carb is faulty and the front coil failed.



Thanks very much to everyone who contributed...it's been hard enough to fix this bike with it in front of me, let alone offering advice based on my (sometimes confused) ramblings




PS Why won't my seat lock down...is there a common fault???

Thanks Guys

Neil

[VTRDark]

Good news on the new set of carbs. I still think the issue was with the needle valve as you where getting a puddle which is more than just running rich. Not sure which vacuum valve your referring to, maybe the air cut off valve which cuts off one of the air bleeds (top of carb where v stack fits), I think on the pilot circuit during deceleration.

For constantly running rich on the front carb, note not in your case with a puddle, interestingly there is a solution for this. According to Factory Pro you can run a rear emulsion tube on the front http://www.factorypro.com/prod_pages/prodh77.html

For persistent over richness at cruise, you can use another rear emulsion tube to lean out the front cylinder. The higher holes delay the onset of fuel delivery. Diagnosed by the need to have the front fuel screw almost closed for best idle - That's a superb test for pilot jet size.

Or the HRC answer to it is to block one of the front slide holes.
http://www.vtr1000.org/phpBB3/viewtopic ... 31&t=28922

But like I said I don't think this is your issue. I would try the carbs with the new float needle valves and see if the problem persists first. It's not good to change too many things at once and then test as you wont find what was causing the problem and could get yourself in a muddle with further diagnosis if required.

The coil failing on the front would be a total coincidence. A coil failing has no relation to bad fuelling. Your over thinking things

(:-})

[Kurt999]

Good news on the new set of carbs. I still think the issue was with the needle valve as you where getting a puddle which is more than just running rich. Not sure which vacuum valve your referring to, maybe the air cut off valve which cuts off one of the air bleeds (top of carb where v stack fits), I think on the pilot circuit during deceleration.

yep thats the one I mean

For constantly running rich on the front carb, note not in your case with a puddle, interestingly there is a solution for this. According to Factory Pro you can run a rear emulsion tube on the front http://www.factorypro.com/prod_pages/prodh77.html

For persistent over richness at cruise, you can use another rear emulsion tube to lean out the front cylinder. The higher holes delay the onset of fuel delivery. Diagnosed by the need to have the front fuel screw almost closed for best idle - That's a superb test for pilot jet size.

I've seen tnis info before but haven't changed anything here as my fuelling symptoms are (WERE woohoo!!!) far to severe for this to make a difference

Or the HRC answer to it is to block one of the front slide holes.
http://www.vtr1000.org/phpBB3/viewtopic ... 31&t=28922

Did I read that this should be done if you change to 2 short stacks?

But like I said I don't think this is your issue. I would try the carbs with the new float needle valves and see if the problem persists first. It's not good to change too many things at once and then test as you wont find what was causing the problem and could get yourself in a muddle with further diagnosis if required.

I put new genuine float valves in with no improvement. Also tested the buoyancy of the floats too

The coil failing on the front would be a total coincidence. A coil failing has no relation to bad fuelling.

I pretty much thought that

Your over thinking things

Yep nothing changes lols

(:-})