Misfire when cold, fine once up to temperature

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Vaughn
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Joined: Sun May 12, 2013 7:10 pm
My Bike: Zxr400

Re: Misfire when cold, fine once up to temperature

Post by Vaughn »

ross46 wrote:i have a set of stock needles for sale if you need them, will have been sonicated by banner and i dont need them as i have dynojets, make me an offer and they're yours, the red stuff can either be crap from the tank, iron oxide (rust) is red, hence why blood is red as it contains iron in the haem group (weird fact) also sometimes the carb cleaner sprays can be weird colours, i had one which was red once sprayed, put in a new fuel filter and check/clean the tank.
I'm pretty sure it was rust in there, when I bought the bike I de rusted the tank straight away and there was loads of crap in there, the filters in the tank were clogged with rust as well.

Just fitted a new inline fuel filter about a week ago and carbs are spanking clean now so hopefully that should rule out fueling problems, haven't had the bike running as I'm waiting for the seal kit.

Would you be prepared to sell just 1 needle and any chance you have a couple of washers off the pilot screws kicking around??

Was telling my girlfriend about my carb cleaning escapades yesterday and told her about the sonic cleaner machine and she said can you put coca cola in it because that cleans penny's real good, got me thinking maybe she is on to something there??
What do you think??
Could give them a sonic clean in coke then another go in the degreaser what I've been using??

Was thinking about getting my bike dyno jetted when it's fixed but can't seem to find a kit for h model, I'm wondering if the kit for l model will fit, looking at the diagrams they look the same??
Vaughn
Posts: 243
Joined: Sun May 12, 2013 7:10 pm
My Bike: Zxr400

Misfire when cold, fine once up to temperature

Post by Vaughn »

Oh yeah forgot to mention as well these are my settings

All carbs had N77R needles with no shims, 90 main jets and 35 pilots

Carb | Pilot screw turns | Float height
1. 2. 9.05mm
2. 2. 10.71mm
3. 2. 10.43mm
4. 2. 10.43mm

Now if you remember I said cylinder 1 is running rich with a black sooty plug. In the table you can see cylinder 1 has a float height of 9.05mm, am I right in thinking that carb would be letting more fuel in to the float bowl and possibly flooding the engine or have I got it the wrong way round??
Vaughn
Posts: 243
Joined: Sun May 12, 2013 7:10 pm
My Bike: Zxr400

Re: Misfire when cold, fine once up to temperature

Post by Vaughn »

Right so I managed to order up the washers for the pilot screws but I can't help worrying about this
ImageUploadedByTapatalk1378654258.938647.jpg
Are those rubber horns meant to sit snugly in the grooves on the carbs?? The rubber on the airbox is mullered and has been squashed out of shape, I assume that will cause an air leak inside the carb??
been trying to find a replacement but can't find a new one
Any ideas??
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ross46
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Re: Misfire when cold, fine once up to temperature

Post by ross46 »

the lower the height of the spark plug number (10mm-9mm) will make it run richer, the rubbers are supposed to be a nice fit in yes. try heating up in a big bowl of hot water, remoulding them, then if you can get a smear of silicon grease and put a VERY light coat on the rubber to help it slip into place without deforming again, if not try looking on ebay or asking on here in the classifieds, Ross
Vaughn
Posts: 243
Joined: Sun May 12, 2013 7:10 pm
My Bike: Zxr400

Re: Misfire when cold, fine once up to temperature

Post by Vaughn »

ross46 wrote:the lower the height of the spark plug number (10mm-9mm) will make it run richer, the rubbers are supposed to be a nice fit in yes. try heating up in a big bowl of hot water, remoulding them, then if you can get a smear of silicon grease and put a VERY light coat on the rubber to help it slip into place without deforming again, if not try looking on ebay or asking on here in the classifieds, Ross
Spot on answer cheers, I'll try that, I've even got a heat gun I might be able to give it a blast with that and try reform it, I'll give that a try tomorrow after work.

So in theory it could be the float height in the carb that's causing my problems, well that and the seals and things anyway,
Gonna do the valve clearances now as well, might as well while the bikes of the road and stripped this far down, I'm sure I read a good guide on here somewhere, have to dig that out now
ross46
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Re: Misfire when cold, fine once up to temperature

Post by ross46 »

viewtopic.php?f=55&t=8002- valve clearances
heat gun may melt the rubber, thats why i siggested hot water, it doesnt tend to melt it as its not as hot as a heat gun and it will do them all nice and uniformly. pm me about the needles if you want them, dont want much for them as theyre just sitting there as spares, ive also got some spare jets if you need some
Vaughn
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Joined: Sun May 12, 2013 7:10 pm
My Bike: Zxr400

Re: Misfire when cold, fine once up to temperature

Post by Vaughn »

Spot on yeah that's was the guide I was looking for, just need to find a decent set of feeler guages, I've got 3 pairs and they all give different readings, my best set are snap on ones but most of the writing has rubbed off so they aren't a lot of good now, wonder if the rocker cover gasket will be the same as an l model
ross46
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Re: Misfire when cold, fine once up to temperature

Post by ross46 »

part number for L model and H2 both '110091732' hope this helps, and pm me about the needles as it would be better to replace if your doing all the rest of it, they're useless to me and will be going on ebay otherwise
Vaughn
Posts: 243
Joined: Sun May 12, 2013 7:10 pm
My Bike: Zxr400

Re: Misfire when cold, fine once up to temperature

Post by Vaughn »

ross46 wrote:part number for L model and H2 both '110091732' hope this helps, and pm me about the needles as it would be better to replace if your doing all the rest of it, they're useless to me and will be going on ebay otherwise
Spot on cheers I'll get one ordered up ASAP.
What needles are they?? the ones in my bike are N77R
Cheers
ross46
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Re: Misfire when cold, fine once up to temperature

Post by ross46 »

ive got two sets, i'll check if either of them are n77R
Vaughn
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Joined: Sun May 12, 2013 7:10 pm
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Re: Misfire when cold, fine once up to temperature

Post by Vaughn »

Happy days, cheers bud
Vaughn
Posts: 243
Joined: Sun May 12, 2013 7:10 pm
My Bike: Zxr400

Re: Misfire when cold, fine once up to temperature

Post by Vaughn »

So just been online and found a set of new rubbers for the duct where the airbox sits on the carb face £112 for 4. Can't believe that it's ridiculous how can they charge that for some rubber.

Might get the yellow pages out and see if I can find someone who can make a set cheaper
Vaughn
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Joined: Sun May 12, 2013 7:10 pm
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Re: Misfire when cold, fine once up to temperature

Post by Vaughn »

Ps should I replace the foam on the snorkel
ImageUploadedByTapatalk1378743872.305663.jpg
It's all gunked up and sticky
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Vaughn
Posts: 243
Joined: Sun May 12, 2013 7:10 pm
My Bike: Zxr400

Re: Misfire when cold, fine once up to temperature

Post by Vaughn »

That's everything cleaned and degreased, airfilters been washed in degreaser as well
ImageUploadedByTapatalk1378746356.403130.jpg
Managed to heat the funnels up with kettle water and sort of mould them back into shape and push them on, hopefully when they cool they'll harden back in shape.
Cheers for the tip seems to have worked a treat

Probably buy a sheet of airfilter foam off eBay and wrap it round the cage
ImageUploadedByTapatalk1378746514.949295.jpg
If it needs it??
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ross46
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Re: Misfire when cold, fine once up to temperature

Post by ross46 »

Can do, would be better to do it as otherwise you will have to change the jetting
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