Running Problems

Hi Guys im calling on the knowledge of the .Org again

last weekend, i did a bit of servicing on the bike (adjusting chain etc.) while i was at it i though i would see how easy it was to change the air filter (at the time i was waiting for my K&N to turn up) so lifted the tank found the airbox and removed the filter, the air box was clean yet a little oily inside so i thought i would clean it out. popped it off the two carbs removed one of the pipes, then found a load more on the left hand side. decided not to bother unplugging and replugging so popped the one pipe back on and cleaned in situe. put it all back together and all seemed fine.

when i came to ride to work on monday it wasnt liking starting unless i used the choke (id not normaly needed the choke, just a bit of throttle) but it is now getting pretty cold in the morning, so this may be normal.

ive now fitted the K&N and its running poor. if you open the throttle fully from closed, instead of pulling strongley like it used to i get a bit of hesitation a couple of pops and bangs and then it starts to accelerate.

my questions are:

A: have i dont somthing
B: what have i done
C: and how do i fix it

Cheers in advance

Marshall

make sure you've connected the rubber pipes to the carbs securely, that no air is sneaking through. they can be a pain in the **** when they're a bit old! the oil is normal- as long as there isn;t too much theres nothing to worry about. Did you touch any of the moving parts in the carb?

Originally Posted by Marshall

Hi Guys im calling on the knowledge of the .Org again

last weekend, i did a bit of servicing on the bike (adjusting chain etc.) while i was at it i though i would see how easy it was to change the air filter (at the time i was waiting for my K&N to turn up) so lifted the tank found the airbox and removed the filter, the air box was clean yet a little oily inside so i thought i would clean it out. popped it off the two carbs removed one of the pipes, then found a load more on the left hand side. decided not to bother unplugging and replugging so popped the one pipe back on and cleaned in situe. put it all back together and all seemed fine.

when i came to ride to work on monday it wasnt liking starting unless i used the choke (id not normaly needed the choke, just a bit of throttle) but it is now getting pretty cold in the morning, so this may be normal.

ive now fitted the K&N and its running poor. if you open the throttle fully from closed, instead of pulling strongley like it used to i get a bit of hesitation a couple of pops and bangs and then it starts to accelerate.

my questions are:

A: have i dont somthing
B: what have i done
C: and how do i fix it

Cheers in advance

Marshall

Is the tickover a bit lumpy I have the same symptoms and think that the carbs could do with a balance

[Biker Biggles]

Symptoms you describe sound like weak mixture,or too much air for not enough fuel.This could be as said cos the aibox is not seated fully on the carbs or it could well be the KN filter.IIRC KN filters flow more air than the standard one so there will be some difference.I think Northwind is our resident authority on this?

[northwind]

I am not But, K&Ns do flow a little better than standard, and some people have had running problems when fitting them. Others didn't. I'm not sure if it's the problem... I'd have a look at the breather hoses (the two at the back of the airbox) to make sure they're not kinked. Probably not that either, but worth checking, it's easy to do. Also, check that the fuel lines aren't restricted, and that the airbox is firmly fitted and pushed right down- if it's not as low as it goes, then it'll be closer to the tank than it should which'll restrict the airflow.

And that's me out of ideas, but a proper mechanic may be along soon with proper troubleshooting ideas.

Sounds like you haven’t seated the airbox properly. Lift the tank again and make sure it is sitting on the carbs correctly, being a v-twin it is easy enough to get it say on the front, but not properly on the back.

As northy said, you might need bigger jets for the K&N. I suggest checking the airbox is seated and putting the stock filter back and see if it runs ok, only when it is running ok like that venture to putting the K&N back in.

cheers guys i appreciate the advice, ill check my airbox tomorrow, see if ive put it on properly, and check the hoses.

ok lads, i took all the airbox off, made sure none of the pipes were disconnected, all was ok, made sure the fuel lines were all ok, and they were.

made sure the airfilter was sealed properly and everything. no difference, i also tightened up the bit that secures the carbs to the engine as they weren't too tight

made sure the plugs were ok and there were, gave the leads a shot of wd40 for good measure anyway.

still exactly the same, you open the throttle, hesitance and then it accelerates.

can the carbs get this out of balance this quickly??

any other ideas??

Marshall

Originally Posted by Marshall

ok lads, i took all the airbox off, made sure none of the pipes were disconnected, all was ok, made sure the fuel lines were all ok, and they were.

made sure the airfilter was sealed properly and everything. no difference, i also tightened up the bit that secures the carbs to the engine as they weren't too tight

made sure the plugs were ok and there were, gave the leads a shot of wd40 for good measure anyway.

still exactly the same, you open the throttle, hesitance and then it accelerates.

can the carbs get this out of balance this quickly??

any other ideas??

Marshall

That isn't a carb balance problem!!!

I presume it was running OK beforehand? So you have disturbed something along the way!!

[Biker Biggles]

Like someone said,put the old filter back in and see if that cures it.