Rough running 9R

mike-s · Post by **mike-s** » Wed Jan 25, 2006 9:12 am

Uhm, i have a GPX 750, so "height" is irrelevant, reading the guide indicates to me that you should get a set of slightly smaller pilot jets, then put the float level back to "stock" and see how you go as your already 2mm off what it should be.

SocialSecurity · Post by **SocialSecurity** » Wed Jan 25, 2006 10:24 am

sorry, mistook you for the OP

9R's generally dont need pilot jets to be changed, stock is a 38 IIRC and theres usually enough adjustment in the pilot screws for that... but my jet kit recommended running around 16mm float height to begin with, and its definately better than 13mm, but i have a full akra system on mine.

Tenoq, its starting to sound like you might be encountering 'lean surge' on low rpm cruise ... perhaps the pilot screws need to come out a half turn or two ... but making sure the float level is around stock would be ideal

Slow and wobbly · Post by **Slow and wobbly** » Thu Jan 26, 2006 7:50 am

I agree with Brighton Kwaka, stock exhaust makes them feel crap between 3500 4000 revs.

Slow and wobbly · Post by **Slow and wobbly** » Thu Jan 26, 2006 7:53 am

For a second opinion go see Mick at Performance Bikes and watercraft on cochranes rd Moorabin 95555088. Very honest

SocialSecurity · Post by **SocialSecurity** » Thu Jan 26, 2006 8:12 am

worth a try, tho i had a pretty average experience with him.

might be worth getting the bike dyno'd to see whats causing it...

try megacycle in keysborough, they do pretty cheap dyno runs

Tenoq · Post by **Tenoq** » Mon Jan 30, 2006 5:21 pm

Slow and wobbly wrote:I agree with Brighton Kwaka, stock exhaust makes them feel crap between 3500 4000 revs.

Yeah, but does the stock exhaust make them feel crap between 0 and 4000 RPM? That's why I have my doubts it'd fix it.

SocialSecurity wrote:worth a try, tho i had a pretty average experience with him.

might be worth getting the bike dyno'd to see whats causing it...

try megacycle in keysborough, they do pretty cheap dyno runs

Problem is, I'm not sure a dyno would catch the problem. Dyno runs are done at full throttle, right? The problem is mostly non-existent when I pin it (other than the usual slight bogging down). It's only when I'm trying to maintain low RPM in first and second gear (particularly first). Say slowing down from 50km/h to 30km/h - impossible to do smoothly. Worse on hot days.

Might be right about fiddling with the pilot screws - I'll have to get it back to Brighton and make them fix it this time.

wisc · Post by **wisc** » Tue May 01, 2007 2:35 pm

Hey there i must have bought this bike! mine does exactly the same!

did you ever find out what the problem was?

my mechanic down at dynoverks is changing the float valves, and playing round with the pilot jets as the are running about 17 to 1, (lean)

up top I'm getting 14 to 1 or something which is pretty good so I'm told.

getting him to do the floats etc too.

Tenoq · Post by **Tenoq** » Fri May 04, 2007 10:00 pm

Didn't buy mine - still for sale though!

I found once I took the mesh off the stock air filter and put an aftermarket exhaust on the problem wasn't as bad as initially. I got a guru to tune her up and that helped too. It was still there, but definitely a lot better.

If I was keeping the bike, I'd probably change the gearing too, so it was revving a little higher while plodding around. See how you go, but I was told at Brighton Kawa that "it's normal, mate."

Rossi · Post by **Rossi** » Sat May 05, 2007 12:35 am

Got to admit that all 9's are not at their best below 3k revs - then again what are you doing going that slow ??

Tenoq · Post by **Tenoq** » Mon May 07, 2007 11:36 pm

Rossi wrote:Got to admit that all 9's are not at their best below 3k revs - then again what are you doing going that slow ??

Trying to keep my license.

Problem is, stock gearing means you're still under 3k RPM at 30-40km/h - that's rather irritating around town! I'd say change your gearing and the problem will be minimised, even if it's not fixed.

wisc · Post by **wisc** » Tue May 08, 2007 12:09 pm

more like masked. in first cruising is probably the worst gonna change my float valves ordered some from the US and change the diaphragms, see if that makes a difference.

its running pretty good after taking it to dynoverks though.

though for some reason the thermos didn't kick in and it got to max temp this morning as soon as it did i turned it off, still not good though.

hope i didn't hurt it... as i said turned it off as soon as it hit it so should be ok.