I was just about to post a similair thread Blue. I was getting 45-48mph easily every day, up to just over 50mph downhill, now I can only seem to get around 45mph, maybe 46 on a good day, even downhill I struggle to reach 48mph now?
I havent really changed anything since I was getting 48mph apart from my torque spring. I was running stock spring but died uphill so went to a 1000rpm and that helped uphill while I still got to 48mph on flats. Since then its died down to 45mph max, 46-47mph downhill? Can get it back up to 48mph using 7.5g rollers but it kills my revs and is crap uphill, I cant live with that so went back to 5.5g.
Last night I tried a 2000rpm torque in but didnt like it, felt low on power. Then I tried a 1500rpm with 6g rollers and thats not bad, almost perfect, apart from im still losing top end somewhere?
I noticed my belt had a thread coming off the edge, cut it off for now and I ordered a new belt too. I wonder if the problems are just down to a worn belt now? Will see how new one goes, should arrive tomorrow.
I also found a leak on my intake manifold, tube from carb to engine, so ordered one of those too meant to arrive tomorrow too. It would not idle at all, just cut out, and im sure my power was down. I have glued it back up and wrapped it in tape for now and it seems ok for a short term fix till new part arrives.
Im hoping fitted the new belt will get my top speed back up, think the manifold is pretty much airtight now so doubt its that cos it idles fine now.