GTS OWNERS CLUB

suit scoot · Posted: Fri Mar 14, 2008 11:45 pm Post subject: mystery speed loss.

i've lost 10mph off my top speed. WTF??

i've cleaned the filter, changed the plug, oil, checked the belt (not the rollers yet so??).

i'm hitting the limiter with a 130 tyre at 80mph (indicated) which is really really odd.

its anoyying because i'm having to ride it flat out to keep up Crying or Very sad

so, apart from the rollers, what else could be the problem?

im mystified by it Confused

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THE STIG · Posted: Sat Mar 15, 2008 12:25 am Post subject:

Maybe the speedo is shagged mate?
Having said that I did notice you struggling to keep up with me last week on my `standard `bike despite you being 5 stone lighter! Laughing

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The Stig rides an Auto so is always in TOP GEAR!

suit scoot · Posted: Sat Mar 15, 2008 12:30 am Post subject:

i've got the edge at the lights though Cool

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THE STIG · Posted: Sat Mar 15, 2008 12:33 am Post subject:

look what .5 of a second has cost you though Laughing

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The Stig rides an Auto so is always in TOP GEAR!

suit scoot · Posted: Sat Mar 15, 2008 12:38 am Post subject:

Innocenti · Posted: Sat Mar 15, 2008 9:36 am Post subject:

belt stretch and roller wear sounds like Wink

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CheekyThomas · Guvernor Joined: 18 May 2007 Posts: 1374

It wont be belt stretch... as you dont get hardly any, the kevlar reinforcment stops 99% of that... Its reduction in belt width that causes the speed loss, as it makes the belt sit lower on the pulleys.

dougl65 · Posted: Sat Mar 15, 2008 6:18 pm Post subject:

I have an idea what may be wrong Ross! When you installed the Polini variator (did YOU install it?) did you leave out the shim/ washer between the variator pulley and the outer driving pulley? I did initially because that's what the destructions say. The instructions are wrong and if followed will accelerate belt wear. If so, replace the shim, get a new STANDARD belt which are now much cheaper and replace it too. Might solve your problem. The effect of leaving out the shim was VERY noticable on mine. It increased engine breaking dramatically. If you throttled off at about 50 or 60 there was a definite breaking effect accompanied by a slight whine which was not normal. See this thread:

http://gtsownersclub.s4.bizhat.com/viewtopic.php?t=379&highlight=

smirnoff · Posted: Sat Mar 15, 2008 7:01 pm Post subject:

my money is on flat rollers Wink

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PHIL....

suit scoot · Posted: Sat Mar 15, 2008 11:14 pm Post subject:

AIRMECH · Inspector Joined: 05 Jan 2008 Posts: 260

Check your valve clearences,wot f--kin` shop you usin` at 55 quid an hour,shame you aint nearer, my shop is only 30p.h.

suit scoot · Posted: Mon Mar 17, 2008 12:51 am Post subject:

came back from the knaresbrough thingybob today and the bloody thing ground almost to a halt.

i slowed down for a corner using the engine braking and it was as if someone was pulling pulling the back brake on and off in a wierd way.

checked the ht lead cap and then when i got home i checked the battery leads and theyre alright.

i must have a really really flat roller or 6.... Shocked

i checked the belt and its in good condition, i just can't get the variator nut off cos its been welded on with a f**kin windy gun Evil or Very Mad

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suit scoot · Posted: Tue Mar 18, 2008 2:11 am Post subject:

so, the plot thickens, rode up to my mates house today.

all duell carriageway, a174.

flat out 89mph.... normal with a 130 tyre at the rear.

on the way home, it'd do 80 with a slight tailwind Confused

but, when i pulled out to overtake a car doing about 65 and ran it wide open, it pulled like crazy up to the limiter (80). quicker than when its running well!

its got a mind of its own.

anyway, should be solved when i get my heavy rollers in and my new standard piaggio belt jobby.

now i have to get my old half pulley and fashion a tool out of it to save me 30 squids labour.

i'll post pics, the verdict and hopefully it should solve the problem, touch wood.

i may even post some nice ones of my new bitubo that should arrive soon, if that piggin courier EVER deliver's it.... along with my new exhaust springs... Evil or Very Mad

i'll go scroundge a new brass nut off white's because its been welded on, its gonna take some force with a torque wrench to loosen that thing Confused

as long as i don't jack the threads on the end of the crank then it should be fine. (this is why i might take it in, if he jacks it, then its not my fault Razz

)

And there is a tiny bit of rust on the end of it where i think some water has came in through the air scoop Confused

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