engine surging/hunting

[Paulfzs]

not sure how long its been doing it i think quite some time now but it wasnt noticeable as much untill i put my new exhaust on and i can hear it.


idle at 1200rpm but bounce up and down about 300rpm or so, not eratic but every few seconds itll go up then settle.. when riding along at a constant throttle i can just about feel it but can hear it in the exhaust tone.


ideas?

[noggythenog]

Needs the carbs balanced

[Paulfzs]

i thought as much, i balanced them before, but new exhaust and a carb clean i had to rebalance but i think i did #4 out and just gave up with "close enough"

[Frosties]

not sure how long its been doing it i think quite some time now but it wasnt noticeable as much untill i put my new exhaust on and i can hear it.


idle at 1200rpm but bounce up and down about 300rpm or so, not eratic but every few seconds itll go up then settle.. when riding along at a constant throttle i can just about feel it but can hear it in the exhaust tone.


ideas?

Could be the onset of involuntary Ticks 

[darrsi]

Plug caps/HT leads, air filter, then carb balance would be my first actions.


Had "hunting" problems years ago on a bike and it was iffy HT leads, even worse in wet/damp weather.


Also check TPS, if that's iffy it will give similar symptoms too.

[Paulfzs]

best not be leads, cant change them on the fzs has to be new coil


ill change the caps because it can only make it better even if i dont notice it.


tps was fine when i last checked about 1000 miles ago.

[darrsi]

best not be leads, cant change them on the fzs has to be new coil


ill change the caps because it can only make it better even if i dont notice it.


tps was fine when i last checked about 1000 miles ago.

No harm in taking a few seconds to check the TPS again, a lot can happen in 1000 miles!


Cut 5mm off end of HT leads to start afresh, these are good replacements:


http://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR0.TRC0.H0.TRS0&_nkw=SD05F&_sacat=0


Or if you want......brace yourself......buy 4 of these. 


https://www.yamahamotorcyclespares.co.uk/product/YAMAHA/5DM823700000/PLUG%20CAP%20ASSY&uid=0

[Paulfzs]

#1 and #2 can't be cut they appear to have been cut before they only just fit as it is.


i have 1 new plug cap as i bought it to replace #1 which kept breaking when wet