loss of speed

[mike65]

Hi all,
I got my pcx125 4 years ago in 2011. I love it; it's great about town, in traffic, nippy, responsive etc. I have kept it well maintained, by the book, with the dealers I bought it from. It has now done just short of 20.000 miles. At first the top speed was 65mph and then it would hit the limiter, not great but perfectly respectable for a 125.
Then, following a service and a new back tyre, when it was less than a year old, the top speed dropped to 61mph when it seemed to hit the limiter. A year later after another service I lost another 3 - 4 mph. Now I can get 55mph flat out, and it hits the limiter. All things considered, for a well maintained Honda pcx this shouldn't happen.
I have tried very hard to get the service mechanics to look at this but they respond with blank faces and puzzlement. In other words B/S.
Does anyone here have any suggestions? Is it possible that the limiter has been altered? either intentionally or unintentionally? Can it it be altered?
I'd be grateful for any advice.

[pcx man]

Has the rollers and belt ever been changed? This is the first thing I would check. Valves been adjusted properly? Sparkplug changed and gapped properly? Tires stock size?

[MikeP]

It sounds like your variator rollers and or belt are worn and need service. As they wear, the rpm goes up and milage/speed goes down. Recomend a tachometer, as it allows you to get a visual on the engine RPM.

[mike65]

Thanks for the advice. I have kept it serviced as required by the book; spark plug, oil changed regularly. I had it serviced two weeks ago and valve clearance was checked for the second time. There was a problem with the back brake which I think is linked to the middle caliper on the front disc (uni-brakes) which was seized. I hope that's the right terminology. That was suggested as possible cause of the speed problem, but since I got her back there is no difference to the top speed but she does seem to respond better when setting off. There is some wear to the rollers and they are due to get changed in march. No feed-back on the belt and will see if that needs changing too. What beats me is the the sharp drop in speed when she was still only months old. I kind of figured that it could be due to a difference in the outside tire diameter but was told it was the same size.
I think they should have done more about this but I don't know enough to put them on the spot.
Thanks for the help. What about the limiter? Is it feasible it was altered?

[gn2]

Assuming the dealer has been doing the servicing correctly at 20,000 miles belt number two will be 5,000 miles old.
If you haven't been invoiced for a new belt already, the servicing hasn't been done correctly.
Tyres have an effect, I reckon the actual circumference of a CityGrip is shorter than an IRC because when I changed to one from an IRC the top speed dropped.
Even with a brand new belt and a new(ish) City Grip, at 15,000 miles my PCX would barely crack 60mph compared to 67mph when new.
I cured this speed deficit by getting a Forza.
All good now

[dkazzed]

+1 on the belts and rollers. Also, have you cleaned or replaced the air filter and checked the tire pressure?

Has your MPGs gone down?

[mike65]

It's interesting what you say about the tyre specs. At the time I thought it was the only logical explanation for the sudden drop in speed. This has nagged me for 3 damned years. I'm going to advance the schedule from March, get a new rear irc tyre, new rollers and a new belt. Incidentally I am pretty certain the belt has not yet been renewed. I know this is my fault as much as theirs, but it should have been done at the required service time. I will be raising this for sure.
I will post again after the service hopefully with good news.
Thanks for all the feedback, it's been very helpful.

[iantys46]

i have exactly the same issues mike :-( have you managed to resolve this ?