I was having problems with the carb holders a while back (leaking loads of air) so I bought 4 new 1's with o-rings from a L3 model from cradleys. I've been told these work better then the old type. Anyway, when the engine is cold it seems to run really smooth and very pokey, soon as the engine warms up, it runs a tad rough losing all that torque
I was just wondering, could it be the o-rings or the carbs holders expanding and leaking air again? I don't think the hot weather helps
Regards
Rich
MillaMeter's ZXR400 Restoration Click HERE!
ZXR400s 4eva! I miss mine already
rich mine is the same mate. But only between 3-4k revs. When cold, pulls fine, when warm is hesitant. And i've changed the inlet rubbers for the same ones. It doesn't seem to have made any difference.
parby81 wrote:rich mine is the same mate. But only between 3-4k revs. When cold, pulls fine, when warm is hesitant. And i've changed the inlet rubbers for the same ones. It doesn't seem to have made any difference.
Hi,
Whats your mixture set at? I checked the plugs today and they were black. But what I don't understand is how can the plugs be black when it was only put on a dyno a month ago.
you running stock carbs?
Regards
Rich
MillaMeter's ZXR400 Restoration Click HERE!
ZXR400s 4eva! I miss mine already
i dont know exactly how the L3 rubbers differ, but im guessing they are longer as they are recommended for use when fitting a few of the ram-air boxes that are available.. anyway ..
any change in the shape/size of the intake system will require the carbs to be tweaked to get the right mixture across the range of both rpm and throttle opening.
and from the symptoms you describe, i'd think the bike is running a fair bit richer than it should be, (in general rich problems get worse as the bike warms up)
either because of the change to L3 rubbers, or... because you fitted them to fix an air-leak which had previously been causing a lean mixture scenario which your carbs had been adjusted to compensate for... ?
make sure your idle mix screw's are 2-2.5 turns out (out is richer, in is leaner) and that the rest of your carb's are in tip top condition.
standard air filter ?
standard exhaust ?
standard jetting ?
standard needles ?
The bike has been taken to a Dyno and was all set up on a rolling road. The guy at the dyno fixed the air leak temp with some silicone gasket sealer which only lasted a couple of weeks. I then noticed it started to leak again (engine started hanging and vibrating like hell) I decided to get the L3 rubbers as they're a much better design. Fixed the air leak no problem. My mixtures are at 3.5 turns (dyno settings) and ran pretty poor untill today.
I left for work this morning at 1am, started the bike and it was only running on 3 cylinders! I thought nothing of it hoping the last 1 would kick in as I went down the road. Nope.... things went from bad to worse as I lost yet another cylinder. At this point the bike was finding it very hard to move and sounded like a Hardly Movedson. I nursed the bike back to garage (even though I was gonna be late for work) and started stripping it down with only the 3 tools I needed and a phone as a tourch. Found out that my coils had packed up. Lucky for me, I bought an engine a while back which came with some coils. Whacked those in and hey presto! bike is now running so sweeeeet it was lifting out of bends on my way to work
.......Then I killed a rabbit
There's still some little flat spots which need smoothening out but that's no match for me.
Regards
Rich
MillaMeter's ZXR400 Restoration Click HERE!
ZXR400s 4eva! I miss mine already
standard carbs and mine are two turns on 2 and 3 and 2.5 on 1 and 4. Problem seem s far worse when warm, and when it gets really warm after a bit of filtering it starts to hang at 2k revs agin. Then as soon as you get going its back down to normal idle. very frustrating. I haven't had the plugs out to check, i might try and do that this weekend. Hve to see if the boss (wife) kets me!! (and yes i do have a thumb print on my forehead!! lol
parby81 wrote:standard carbs and mine are two turns on 2 and 3 and 2.5 on 1 and 4. Problem seem s far worse when warm, and when it gets really warm after a bit of filtering it starts to hang at 2k revs agin. Then as soon as you get going its back down to normal idle. very frustrating. I haven't had the plugs out to check, i might try and do that this weekend. Hve to see if the boss (wife) kets me!! (and yes i do have a thumb print on my forehead!! lol
Hi,
Yeah it would be a good idea to check the plugs, I just checked mine and they're all over the place. 1,3 and 4 are all sooty and 2 is perfect. I've just turned in the mixture on 1,3 and 4 a tad leaner by 1/4 turn. I whiped the plugs out this morning and they are getting a bit of colour in them now (starting to look like a rich tea biscuit) still need some tweaking, but hey! that's old skool carbs for ya
By the sounds of it, I'm gussing 2 & 3 are just a lil bit too lean. Try turning them out by 1/4 turn.
If you have any problems, you know where to find me
Regards
Rich
Last edited by MillaMeter on Thu Jul 31, 2008 12:02 pm, edited 1 time in total.
MillaMeter's ZXR400 Restoration Click HERE!
ZXR400s 4eva! I miss mine already
well they all look biscuity to me, kind of a dark biscuit, just off ginger nut i'd say. If you pm your number i'll send you a pic, so you can cast your eye over them. Gonna empty the carbs and check they're all clean and clean all the filters on the bike. Then i might try swapping the plugs and leads. Does anyone no if car HT lead will work on a bike? Are the leads of the same kind of construction?
well thats what i thought. I've stripped down the carbs this afty and was going to give them a spray with some carb clean. They look bloody clean though as i've already done this once. I think i'll pop out and see if i can get some new plugs and then butcher some HT leads.
Zimm, would the half a tooth on the cam chain affect this as i think it is slightly out?
