Bogging down at 8K - SV650.org

09-10-08, 08:48 PM

I have a y reg curvy which I dropped over a year ago. Since then she's been patched up and running fine albeit with 'battle scars'. However after 3 months laid up she wouldn't start. So I cleaned the spark plugs and gave her some fresh fuel. Beauty. Running nicely until 8 thou RPM when she bogs down. I've now had the carbs off and cleaned them out really well with air and carb cleaner. But the problem remains. At 8k she bogs down. The exhaust seems to be running hot and is backfiring badly at 8-10k. Past this it runs fine.

Spraying carb cleaner into the carbs as I rev lets the bike rev freely through the 8k problem which made me think that it was poor fuel so I've swapped the fuel and put some redex in to no avail.

Any ideas?

Bibio · 09-10-08, 09:37 PM

have you tried a new set of plugs?

or try the connectors to the coils they may be loose.

17-10-08, 02:36 PM

I've cleaned up the plugs I have fitted. I'll give a new set a go as they're not expensive. The leads seem to be on securely but I'll check them. Sorry for the long delay, I've been away for a while.

BoltonSte · 18-10-08, 06:08 AM

What about the foam under the tank? I know it can come loose enough to be sucked onto the filter but I can't remember when it usually happens.

Give it a pull, it may looked stuck on but is ono weakly.

18-10-08, 07:50 AM

Cheers SVSte but I've had the air box right off and cleaned. It was clean anyway but I'm being really thorough with everything as I need to get the bike running ASAP. I'm at work tomorrow (where the bike is currently living) so I'll swap the plugs then.

19-10-08, 09:44 PM

Could be an air leak somewhere. Check the carb rubbers and airbox as the jault could have dislodged something.

26-03-09, 09:43 PM

A very old bump but just in case someone else is suffering from the same problem. In the end I changed the battery as I was selling the bike and the battery on the bike was past it's best. All sorted. Running sweet as a nut now.

26-03-09, 10:24 PM

Carbs still aint clean so it's running lean at the top end as proved by spraying cleaner in and the problem goes away. Try again Sir

27-03-09, 10:54 PM

The carbs are gleaming. A mate who's a car mechanic helped me out with them.

The problem with using carb cleaner is that it detonates easier than petrol and hence didn't need such a strong spark to ignite.

Running it on carb cleaner was only working now and then. I took her out on Thursday for a good run and she really is running well. TBH I'll be sad to see her go but it's all for the greater good (More CC's).

09-10-08, 08:48 PM	#1
Heed Guest Posts: n/a	Bogging down at 8K I have a y reg curvy which I dropped over a year ago. Since then she's been patched up and running fine albeit with 'battle scars'. However after 3 months laid up she wouldn't start. So I cleaned the spark plugs and gave her some fresh fuel. Beauty. Running nicely until 8 thou RPM when she bogs down. I've now had the carbs off and cleaned them out really well with air and carb cleaner. But the problem remains. At 8k she bogs down. The exhaust seems to be running hot and is backfiring badly at 8-10k. Past this it runs fine. Spraying carb cleaner into the carbs as I rev lets the bike rev freely through the 8k problem which made me think that it was poor fuel so I've swapped the fuel and put some redex in to no avail. Any ideas?

09-10-08, 09:37 PM	#2
Bibio Member Mega Poster Join Date: Jul 2008 Location: here as devil's advocate Posts: 11,569	Re: Bogging down at 8K have you tried a new set of plugs? or try the connectors to the coils they may be loose.

17-10-08, 02:36 PM	#3
Heed Guest Posts: n/a	Re: Bogging down at 8K I've cleaned up the plugs I have fitted. I'll give a new set a go as they're not expensive. The leads seem to be on securely but I'll check them. Sorry for the long delay, I've been away for a while.

18-10-08, 06:08 AM	#4
BoltonSte Member Mega Poster Join Date: Aug 2003 Location: Back in Bolton Posts: 1,010	Re: Bogging down at 8K What about the foam under the tank? I know it can come loose enough to be sucked onto the filter but I can't remember when it usually happens. Give it a pull, it may looked stuck on but is ono weakly. __________________ Had an SV or three. Street triple R - gone but not forgotten. Now trying the lunacy that is KTM with a Superduke GT. for the pillion capability of course.

18-10-08, 07:50 AM	#5
Heed Guest Posts: n/a	Re: Bogging down at 8K Cheers SVSte but I've had the air box right off and cleaned. It was clean anyway but I'm being really thorough with everything as I need to get the bike running ASAP. I'm at work tomorrow (where the bike is currently living) so I'll swap the plugs then.

19-10-08, 09:44 PM	#6
jimmy-james Guest Posts: n/a	Re: Bogging down at 8K Could be an air leak somewhere. Check the carb rubbers and airbox as the jault could have dislodged something.

26-03-09, 09:43 PM	#7
Heed Guest Posts: n/a	Re: Bogging down at 8K A very old bump but just in case someone else is suffering from the same problem. In the end I changed the battery as I was selling the bike and the battery on the bike was past it's best. All sorted. Running sweet as a nut now.

26-03-09, 10:24 PM	#8
Rocket Guest Posts: n/a	Re: Bogging down at 8K Carbs still aint clean so it's running lean at the top end as proved by spraying cleaner in and the problem goes away. Try again Sir

27-03-09, 10:54 PM	#9
Heed Guest Posts: n/a	Re: Bogging down at 8K The carbs are gleaming. A mate who's a car mechanic helped me out with them. The problem with using carb cleaner is that it detonates easier than petrol and hence didn't need such a strong spark to ignite. Running it on carb cleaner was only working now and then. I took her out on Thursday for a good run and she really is running well. TBH I'll be sad to see her go but it's all for the greater good (More CC's).