Back firing, flame sout the exhaust etc, where do I start looking? - Page 2 - SV650.org

yorkie_chris · 24-10-11, 08:02 PM

TRE mod. Slightly different ignition map depending on gear position, nothing to worry about.

Taipan · 24-10-11, 08:06 PM

Cool, ta.

Taipan · 25-10-11, 06:28 PM

Just been out and pulled the front plug cap off and started it up with a plug in the cap and it has a big strong spark.

I've ordered some new plugs and will fit them thursday as a matter of course.

I'll also strip the carbs and give them a clean as I'm now wondering if its something like a blocked pilot/slow jet? I did drain the float bowl but it didn't solve anything.

But I'm also reminded of my old SV which displayed similar symptoms and it was due to the internal drain (which runs from the filler cap through the tank and out the back) rusting through and letting water into the tank and subsequently the carbs. That only ran on one cylinder until I changed the tank and fuel. But the drain does seem to blocked at all, so hopefully a carb clean and new plugs will solve it.

Taipan · 27-10-11, 09:59 AM

Hmmm I don't suppose this would help, but would it be the cause?

yorkie_chris · 27-10-11, 11:05 AM

That'd do it!

Taipan · 27-10-11, 12:34 PM

I hope that is it as jets are clear and choke plungers free etc. Of course its absolutely pouring down now and I've had to retreat inside and leave the bike undercover! Damn this bloody rain I want to get it back together and fit the new indicators etc and get it ready for the MOT. Typical that I take the day off to work on the bike and it turns into monsoon season!

Taipan · 27-10-11, 02:16 PM

Quote:

Originally Posted by yorkie_chris

That'd do it!

You were on the money as usual Chris! Put it back together and cranked the fuel though and straight onto two cylinders!

Its not running perfect but I expect that plug isn't what it could be. I'm waiting on my new plugs and hope that will cure it completely. Dunno if you'd even notice it to ride but at a constant throttle you can just hear its not quite 100%.

Float bowls were very clean and the chokes had been out recently so I guess they'd been chasing this and just missed the little plug?

Got some new indicators and a number plate to fit and then it should be ready for its MOT. Could use a rear sprocket and a new chain is always ideal but i'll get them next payday and after the MOT.

Cheers for the advice.

27-10-11, 02:45 PM

Doesn't say in any of your posts that you're using fresh fuel, so completely drain the fuel tank, thoroughly flush it out with fresh fuel, then refill (with fresh fuel obviously). It's anybody's guess what's in the tank.

Taipan · 27-10-11, 04:51 PM

Hi Irie! Will do just that..

24-10-11, 08:02 PM	#11
yorkie_chris Noisy Git Mega Poster Join Date: Apr 2007 Location: Halifax/Leeds Posts: 26,645	Re: Back firing, flame sout the exhaust etc, where do I start looking? TRE mod. Slightly different ignition map depending on gear position, nothing to worry about. __________________ Currently Ex Biker Now rebuilding a 63' fishing trawler as a dive boat

24-10-11, 08:06 PM	#12
Taipan Member Join Date: Mar 2007 Location: Basildon, Essex Posts: 785	Re: Back firing, flame sout the exhaust etc, where do I start looking? Cool, ta.

25-10-11, 06:28 PM	#13
Taipan Member Join Date: Mar 2007 Location: Basildon, Essex Posts: 785	Re: Back firing, flame sout the exhaust etc, where do I start looking? Just been out and pulled the front plug cap off and started it up with a plug in the cap and it has a big strong spark. I've ordered some new plugs and will fit them thursday as a matter of course. I'll also strip the carbs and give them a clean as I'm now wondering if its something like a blocked pilot/slow jet? I did drain the float bowl but it didn't solve anything. But I'm also reminded of my old SV which displayed similar symptoms and it was due to the internal drain (which runs from the filler cap through the tank and out the back) rusting through and letting water into the tank and subsequently the carbs. That only ran on one cylinder until I changed the tank and fuel. But the drain does seem to blocked at all, so hopefully a carb clean and new plugs will solve it. Last edited by Taipan; 25-10-11 at 07:55 PM.

27-10-11, 09:59 AM	#14
Taipan Member Join Date: Mar 2007 Location: Basildon, Essex Posts: 785	Re: Back firing, flame sout the exhaust etc, where do I start looking? Hmmm I don't suppose this would help, but would it be the cause?

27-10-11, 11:05 AM	#15
yorkie_chris Noisy Git Mega Poster Join Date: Apr 2007 Location: Halifax/Leeds Posts: 26,645	Re: Back firing, flame sout the exhaust etc, where do I start looking? That'd do it! __________________ Currently Ex Biker Now rebuilding a 63' fishing trawler as a dive boat

27-10-11, 12:34 PM	#16
Taipan Member Join Date: Mar 2007 Location: Basildon, Essex Posts: 785	Re: Back firing, flame sout the exhaust etc, where do I start looking? I hope that is it as jets are clear and choke plungers free etc. Of course its absolutely pouring down now and I've had to retreat inside and leave the bike undercover! Damn this bloody rain I want to get it back together and fit the new indicators etc and get it ready for the MOT. Typical that I take the day off to work on the bike and it turns into monsoon season!

27-10-11, 02:45 PM	#18
irie Guest Posts: n/a	Re: Back firing, flame sout the exhaust etc, where do I start looking? Doesn't say in any of your posts that you're using fresh fuel, so completely drain the fuel tank, thoroughly flush it out with fresh fuel, then refill (with fresh fuel obviously). It's anybody's guess what's in the tank.

27-10-11, 04:51 PM	#19
Taipan Member Join Date: Mar 2007 Location: Basildon, Essex Posts: 785	Re: Back firing, flame sout the exhaust etc, where do I start looking? Hi Irie! Will do just that..

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