Flat spot

mohawk miss · Post by **mohawk miss** » Sun May 07, 2006 4:58 pm

The zzr250 has, since getting the fuel issues fixed, developed a noticable flat spot, especially in 1st and 2nd. It kind of "bogs", then goes, and in higher gears there is a very noticable hesitation.

Am I right in thinking that the carbies need adjusting? Or could it be somthing else?

And does anyone know a good mechanic around Penrith who wont bankrupt me? (that leaves out Kelens.....

)

RG · Post by RG » Sun May 07, 2006 5:12 pm

For mine, I feel a sudden boost in power after 9k rpm.

I'm not sure if that's a good thing or not.

Johnnie5 · Post by **Johnnie5** » Sun May 07, 2006 6:10 pm

prob in need of a carb balance

Heard good reports about Mick Dyers in Penrith

Want to save yourself some money then remove the fairings before you take it in , prob up to an hours labour in that there

mohawk miss · Post by **mohawk miss** » Sun May 07, 2006 8:48 pm

Anyone heard anything about TJ's in Minchinbury?

I'll definately suss out Mick Dyers though. Thanks

chameleon · Post by **chameleon** » Tue May 09, 2006 5:05 pm

I have read that the two most common reasons for a flat spot are plugged idle/main jet and/or an intake leak. You can check the clamps on ya inlet manifolds first, then remove and clean the jets. How's your fuel filter system, and did you change the octane ratting on the fuel you use recently Miss Mohawk?

mike-s · Post by **mike-s** » Tue May 09, 2006 5:45 pm

A symptom of air leaks is the revs hanging in the air and being reluctant to go to idle after the engine is revved, moreso the larger the leak. Also the engine will run a bit better after it has warmed up. Also although it doesnt really relate here, if it got a bit worse after warming up, that would mean its running rich.

To check for air leaks is best done by spraying aerostart over the carb boots. if the revs rise, you've a leak. Just make sure you don't spray near the air intake as it'll give a false positive or manage to knock yourself out as it's got ether in it.

A cheap attempted fix is to first drain the floats to try and get any crap out and then put a half bottle of carby cleaner through the engine with a full tank and see if that helps it any.

Failing that a carb-synch will hopefully fix the problem. If i was a lot closer i'd offer some help with doing it this w/e as aside from putting tank and bits of plastic on & off it took me about 20-30 minutes to synch 4 carbies. would take 5-6 minutes to synch a twin

.

If that doesnt fix the problem, then a carb overhaul may be in order, good luck.

mohawk miss · Post by **mohawk miss** » Tue May 09, 2006 7:05 pm

Thanks guys.

This bike only gets BP Ultimate, so its not the octane....

Im leaning towards some sort of float prob, as it tends to hesitate more if turning sharp right. The BF suggested this may be because I am better cornering left than right and it may be a rider error when cornering.

It doesnt get worse when cold or hot, and actually seemed to rev low at idle at normal run temp (I have adjusted idle up a little since).

As I am not overly mechanically minded and will admit the inside of my bike is mostly a mystery (despite being a mechanic's daughter!)

, so I am happy to pay someone to fix it for me. But I'll try the carby cleaner first.

ZZRCHIKKY · Post by **ZZRCHIKKY** » Tue May 09, 2006 7:41 pm

BP Ultimate

the only thing my car ( that i dont drive) will run on he he he , and god i put it in my bike today and it loved it !!!

Go bp ultimate

mohawk miss · Post by **mohawk miss** » Wed May 10, 2006 7:30 pm

We dont use any other fuel if we can help it, have managed to get 300k's on a tank (before reserve) just puttering around Penrith and Blacktown.

Although ATM I dont think it will get anywhere near that mileage...

ZZRCHIKKY · Post by **ZZRCHIKKY** » Sun May 14, 2006 1:09 am

i just relised mine has the same problem - its arounf 8k rpm though and then gets up at 9k rpm, but when its on ultimate it dosnt happen

mohawk miss · Post by **mohawk miss** » Tue May 16, 2006 4:07 pm

Just realised I forgot to ask, the carby cleaner for cars, or is there a special one for bikes?

chameleon · Post by **chameleon** » Sat May 20, 2006 10:45 am

I wouldn't imagine so.. Same fuel, same gunk building up.

sneakypete · Post by **sneakypete** » Sat May 20, 2006 1:47 pm

mohawk miss wrote:Anyone heard anything about TJ's in Minchinbury?

Yeah, i know Tex,he is a mate of my mate... he is pretty good. wont charge an arm n a leg, nice guy too (but a bit dry). i've had him work on my 400 & my car a few times when i lived out that way.

his phone number is 9675 5888

chameleon · Post by **chameleon** » Sun May 21, 2006 10:44 pm

Hey there miss, how's it going? I did a job under the tank the other day and after I put it all back together I had a flat spot too

The next day I went back under and tightened the carb-to-head manifold screws and she was right as rain after that

mohawk miss · Post by **mohawk miss** » Mon May 22, 2006 12:06 pm

Thanks Chameleon for that tip. Got some carby cleaner from Western's, and hopefully will be fit enough to ride the poor thing this week.

Otherwise will be getting some surprise dollars, and that can go towards a service.