Post by EyeSee on Jul 4, 2006 10:06:30 GMT
My Baotian BT50QT-9 has now done 1150km and, after 700km, eventually got my wife and I both up the hill home without one of us having to get off, (see my previous ‘More uphill speed required!’ back in February). To achieve this, I was just patient and allowed the scooter to run in. I did not change the roller weights or anything.
However, the last month or so, a problem appears to be developing and it is losing power up hill. If I make the 15km round trip journey to the island’s main town, the scooter manages the two steep climbs going there no problem. However, on the return, it struggles as it did when it was new.
I would point out that the problem started as daily temperatures here in Greece started to hit 30ºC and above, (possibly a coincidence). Is it possible that the heat is causing the drivebelt to stretch? Has anyone else experienced this? (There is a heat wave in the UK at the moment so I see on the news!) The scooter being black and the drivebelt casing being black too and poorly ventilated may not help either.
I will have the casing off at the weekend to see if there is anything obvious, eg worn belt teeth or oil. There is a possibility that some petrol may have seeped in recently. I had dirt in the carb and to get it started, I had to use throttle and flooded it several times. Petrol poured out of the carb and back to the air filter and leaked out all over the drivebelt casing! However, the uphill problem started weeks before the dirty carb problem.
Can anyone give me any advice on what my problem may be and any suggestions re: drive belts. I have already read some info on drive belts in Madtim’s ‘Roller answers needed’ and Joe’s ‘Drive belts’. I am sure it is gearing related, so please, no suggestions re valve clearances or spark plugs (NGK already fitted).
If I could resolve the above problem and still want to make a modification to improve my uphill speed, I get the impression a stronger contra spring would be a better solution for our particular situation and would help tension the drive belt if it is slackening in the heat, as opposed to fitting lighter roller weights, see quotes below:
From Cantlogin:
“The spring in the rear driven pulley only controls the gearing by varying the position the belt sits, in the pulley. A stronger spring would make the belt sit higher, giving a lower ratio (slower speed/higher engine revs), whereas a weaker spring will give a higher ratio (faster speed/lower engine revs). The real issue, which would warrant changing the gearing ratio, is whether the bike has low enough gearing to climb the steepest hill you need, and is not revving it's nuts off downhill at the other extreme, taking the power it has available into consideration.”
From www.teamcalamari.com/zuma/variator.html
“If your roller weights are giving you good acceleration, and a good top end, but when you approach a small hill the scooter slows drastically, this may be caused by having too light of a contra spring.”
Has anyone tried this? If they have did it work? What is the rating on the standard spring and what rating did you fit? Remember, I don’t want sports performance, just to get up hills with some respect!!!!! Visit www.kalymnos-isl.gr to see where I live and you will get an idea of the terrain!!!!
Many thanks
Eye See
However, the last month or so, a problem appears to be developing and it is losing power up hill. If I make the 15km round trip journey to the island’s main town, the scooter manages the two steep climbs going there no problem. However, on the return, it struggles as it did when it was new.
I would point out that the problem started as daily temperatures here in Greece started to hit 30ºC and above, (possibly a coincidence). Is it possible that the heat is causing the drivebelt to stretch? Has anyone else experienced this? (There is a heat wave in the UK at the moment so I see on the news!) The scooter being black and the drivebelt casing being black too and poorly ventilated may not help either.
I will have the casing off at the weekend to see if there is anything obvious, eg worn belt teeth or oil. There is a possibility that some petrol may have seeped in recently. I had dirt in the carb and to get it started, I had to use throttle and flooded it several times. Petrol poured out of the carb and back to the air filter and leaked out all over the drivebelt casing! However, the uphill problem started weeks before the dirty carb problem.
Can anyone give me any advice on what my problem may be and any suggestions re: drive belts. I have already read some info on drive belts in Madtim’s ‘Roller answers needed’ and Joe’s ‘Drive belts’. I am sure it is gearing related, so please, no suggestions re valve clearances or spark plugs (NGK already fitted).
If I could resolve the above problem and still want to make a modification to improve my uphill speed, I get the impression a stronger contra spring would be a better solution for our particular situation and would help tension the drive belt if it is slackening in the heat, as opposed to fitting lighter roller weights, see quotes below:
From Cantlogin:
“The spring in the rear driven pulley only controls the gearing by varying the position the belt sits, in the pulley. A stronger spring would make the belt sit higher, giving a lower ratio (slower speed/higher engine revs), whereas a weaker spring will give a higher ratio (faster speed/lower engine revs). The real issue, which would warrant changing the gearing ratio, is whether the bike has low enough gearing to climb the steepest hill you need, and is not revving it's nuts off downhill at the other extreme, taking the power it has available into consideration.”
From www.teamcalamari.com/zuma/variator.html
“If your roller weights are giving you good acceleration, and a good top end, but when you approach a small hill the scooter slows drastically, this may be caused by having too light of a contra spring.”
Has anyone tried this? If they have did it work? What is the rating on the standard spring and what rating did you fit? Remember, I don’t want sports performance, just to get up hills with some respect!!!!! Visit www.kalymnos-isl.gr to see where I live and you will get an idea of the terrain!!!!
Many thanks
Eye See