SuzukiSavage.com - Print Page

SuzukiSavage.com
/cgi-bin/YaBB.pl
General Category >> Rubber Side Down! >> backfiring blowing off carb
/cgi-bin/YaBB.pl?num=1446237245

Message started by Steddy58 on 10/30/15 at 13:34:05

Title: backfiring blowing off carb
Post by Steddy58 on 10/30/15 at 13:34:05

Hey everyone,riding along then it started backfiring and it stopped , I had the carb off and cleaned but same problem it starts for about 20 seconds then it dies and feels like fuel but it backfires like crazy .It feels more like fuel than electrics but I'm at a loss any ideas?

The above was written on my phone hoping that someone might have an idea while I was at the bike but now I am at home at my pc so a few more details - I had the bike repainted about a month or so ago - tank and mudguards - since replacing the parts I've had problems firstly the electrics were playing up ( lights, horn, starter etc only the rear light was playing the game ) but once they came back on line the bike ran ok finally we found a dodgy earth and have repaired it - but as soon as that was sorted the bike stopped after a ride of about 10 miles - I pulled over and tried the starter again, it would fire up and last about 10 - 15 seconds and then die as if it was petrol starvation but accompanied by horrendous backfiring flames out of the exhaust and backfiring through the carb as well, I called out the RAC ( the equivalent to the AAA in the USA ) who tried to repair it and his idea consisted of revving the balls out of it so that the header pipe was glowing red hot :o but anything lower than warp 10 and it backfired and died, it sounded like when I had the old brit bikes and the timing was way out. After messing around with the idle adjustment and the air mix screw it went for about 50/75 yards of fairly noise and backfire free riding but it stopped and didn't go again which resulted in a fairly hair-raising 45 minutes being towed by my mate on his BSA A7 through the fairly busy roads of Birkenhead back to his house where we have been trying new spark plugs etc but the spark seems ok which I presume means the coil and igniter unit are ok we cleaned the carb which seemed to have a little bit of crap in it which looked like it might be the sanded down bondo from the tank (I have an in line filter which was free of crap that could be seen by the naked eye). The jets seemed free of dirt but there appeared to be a very small amount of a putty like substance inside the carb but it was on the body rather than the jets or air holes etc. should I do an in depth clean of the carb before going on to other targets ? The carb is a mikuni which was bought from lancer and is normally spot on, if anyone needs any more info please ask and I will try and supply it, cheers one and all

Title: Re: backfiring blowing off carb
Post by marekbuk on 10/31/15 at 02:57:05

Hi

I had a similar experience years ago when my first Savage died on me and coincidently I had a hair raising tow through Huddersfield.

The bike would only run with the throttle 1/2 to full open

I took the carb apart and blew compressed air through all the jets, put it back together again and all was well

hope this helps

good luck

Mark

Title: Re: backfiring blowing off carb
Post by Art Webb on 10/31/15 at 10:59:08

sounds like the Pilot jet is fouled, try the trick with the compressed air (don't let the jet get away from you) and see if that helps
Also check you petcock for proper function

Title: Re: backfiring blowing off carb
Post by Steddy58 on 10/31/15 at 14:17:51

Just a quick update swapped carbs and put on the original which improved matters just a little bit but it did the same thing started then died (the bike ran a bit longer with the original carb before dying) but it appeared that when the starter button stayed depressed the engine kept going - is this info of any use ?. I haven't tried blowing the carb yet or had a look at the petcock. My bike is at me mates and hes trying a few things. Just an idea but the two thin wires on the starter relay ( one is black and white ) do they have to go on in any particular way, thanks for the ideas so far.

Title: Re: backfiring blowing off carb
Post by Steddy58 on 11/03/15 at 16:59:54

OK another update I have blown through the carb with compressed air have replaced the starter relay with new the right hand switchgear with new the ignition with new and still the problem persists engine starts and when starter button is released the engine cuts out - I really am at the end of my tether - I am beginning to exhibit the early signs of madness lol. This must be electrical or...mechanical or..... fuel or..or..or perhaps god just hates me. Methinks soon the river Mersey will be home to another motorbike or rider perhaps both! If I post no more you will understand :( goodbye cruel world :'( :'(.

Title: Re: backfiring blowing off carb
Post by Steve H on 11/03/15 at 19:53:14

If it dies as soon as the starter button is released, like you turned off the switch, you might not be getting power to the igniter box except for the retard signal applied while starting.

Get out your wiring diagram and follow the power from the ignition switch to the ignition box. There's probably an open somewhere in there.

At this point, I'd check for spark without the starter circuit engaged. If you still have spark, this isn't your problem. and it must be either fuel or mechanical. You have tried a different, known good, spark plug?

Title: Re: backfiring blowing off carb
Post by Steddy58 on 11/04/15 at 04:27:07

Cheers for that SteveH will try later on today - the spark plug is new and it is sparking when the start button is depressed but will check the way you said more updates later thanks

Title: Re: backfiring blowing off carb
Post by Steddy58 on 11/05/15 at 01:16:02

Right then more news from the UK - the problem child has decided to start playing the game ( cue much applause and cheering ) although it has not been on the road yet it seems that after all the head-scratching and soul searching it now runs after you have taken your finger off the starter button. Its not exactly known how we did it but after removing the alternator cover and taking extra care when replacing it and undoing then re-tightening a couple of connections that go to the coil and a new ignition switch it runs and ticks over like it should - thanks to those that replied with advice ( marekbuk, Art Webb and Steve H ) which was followed i.e. cleaning carb, checking spark without starter circuit engaged etc. Hopefully I can now ride off into the sunset whistling a happy tune ( or at least ride off into the drizzle complaining about the crappy weather in the UK ) see you all later ;)

Title: Re: backfiring blowing off carb
Post by marekbuk on 11/06/15 at 09:00:46

Great news! :)

Now get out there and Enjoy your rides - well maybe not this weekend but when it dries up eh?

Mine is staying in my garage until this spell of wet weather passes over - at least its mild :)

Title: Re: backfiring blowing off carb
Post by Art Webb on 11/06/15 at 10:10:10

sweet! now you can enjoy your ride, once the weather clears
I recently bought a new helmet so weather here is rainy, too
It's like a natural law or something, Art buys a moto related something, it rains
Didn't know I was affecting weather patters alla way to the UK ;D
sorry

Title: Re: backfiring blowing off carb
Post by Steddy58 on 11/07/15 at 10:17:15

LOL spoke too soon - halfway home started bucking like a rodeo bronco, this went was on and off for 5/6 miles then it finally conked out ( I noticed that the rev counter was bouncing about as well - so maybe its the coil ? ) I had a spare igniter in me pocket put that on and it still wouldn't start, the fuel seemed to be flowing ok and battery was good - and just for good measure as I had broken down outside a pub the usual drunk old man come along giving it " I've been riding bikes for 50 years and the problem is you've been buggering about with put it all back as standard and it will work, youve got the wrong carb on it - the handle bars aren't right blah blah blah " for half an hour - just what you need at half past midnight when you know you'll be waiting two hours for a pick-up truck and you've spent 3 weeks replacing parts resoldering joints and getting covered in crap with your mate (who also has 50 years experience with bikes) and then finally when you think its sorted it does it again. Whats the soddin' point.

Title: Re: backfiring blowing off carb
Post by KennyG on 11/07/15 at 10:43:35

You have checked that the vents in the fuel cap are open and not clogged?

Kenny G

Title: Re: backfiring blowing off carb
Post by Art Webb on 11/07/15 at 10:50:19

My response to old drunk: So why the F are you drunk in a bar instead of out riding your perfect unmolested factory bike right now? Piss Off

Title: Re: backfiring blowing off carb
Post by Steddy58 on 11/07/15 at 14:19:28

My response to old drunk: So why the F are you drunk in a bar instead of out riding your perfect unmolested factory bike right now? Piss Off

My thoughts exactly Art unfortunately the world is full of barrack room lawyers best to ignore the old sod.

Yeah everything is cool in that direction KennyG.

Just a thought but does anyone know what readings I should be getting when testing the pick up coils? I had a search but couldn't find anything cheers all