Hi all. I was given a Piaggio NRG Power DT and after 100 metres it died. A new cylinder kit was installed and it ran great, started first time, would easily get to 45 before slowly increasing to 50 (max, although downhill it reached 56 and cold hold it there). 3000 miles later its died again. Would turn over as usual but it wasn't starting. It died after a sudden high pitched whine going 40 . Removed the cylinder head, cylinder and piston and will attach some photos. They aren't the best quality but if necessary I can find them on the camera and put them on. The scoring on the piston suggests (according to the manual we have) that the scoot is running too hot? The piston rings are stuck, and as you can see there is metal or something against the cylinder head. I hope you guys know what is the issue as we don't want to take it back to the repair shop (although they are reputable and nice guys). Thanks, Eathan.
looks like it was not set up correct. very black on the piston top and head for a new kit, wouldnt expect that sort of coke build up so soon. signs of blowback on the piston skirt where rings failed, were lucky not to have a full sieze. were both gudeon clips in the piston when you removed it ? maybe ones been thrown out due to not being seated correctly. i would say autolube was not correctly adjusted and gave enough lube for the new kit and has just let the temp raise to much for the rings and piston to cope with. Another point is that bottom gasket is the incorrect one for the kit you have to images 6-7 show a large extra port section in the gasket wher ethe cylinder does not have it. any mech would have known its the incorrect gasket. And Welcome to the scootershack fella
Thanks muchly Both clips were in the piston, but the rod or whatever (thing sticking out of the piston in the pictures) was very hard to remove that much (I guess the heat caused it to expand or something?). About the gasket that was something we noticed. The gasket looked fine against what the cylinder bolted on too, but against the cylinder it doesn't match up. Thanks for the help
thats a 4 point score, very typical in engine that have ran too hot, usually because they are ridden too hard from cold, or lack of coolant, that being an AC kit i would say the former. its a little sooty looking but not too lean.... so next time let it warm up before you ride it hard
It had a couple minutes warm up time before each time I rode it, a minimum of 2 generally while I put helmet on etc, but if I didn't have too rush anything up to 10 really. Any idea on how to adjust the auto lube, if possible? Going to do a full service as we didn't take into consideration the fact that the previous owner most likely (judging by the state of the bike when we got it) didn't do any servicing on it.
That looks like a 70 kit? Should run a little extra oil in the tank as the standard pump output isn't really enough for a good lube if it is. But to have that much soot that far down the piston indicates that the bore is somewhat oval, probably on the exhaust side
That's a new kit and looks like that?. Feel sorry for that kit man. That's the problem with 70s. People install them like they would with a 50, use to many gaskets with the wrong squash clearance , not enough oil, reving the shit out of it when cold like he said above, not running the kit in properly. Personally for new kit you shouldn't even be going 40 50 at all...say good bye to that kit god knows what you done to that poor Polini .
its got 3000 miles on it but 56mph down hill thats over revving that little 50cc sport kit ( i think its a 50cc sport kit not a 70 kit ). if its a 70kit its been wored to hard on stock ratios and been fried , a gear up kit would be the best option to bring that speed up and not have obver rev at 56mph ( he should be pulling like 60-65 with a 70 kit fitted, but stock ratios just wont give that speed easy without hammering the kit hard)
The walls of the bore look too thin to be a 50 kit, and the piston appears bigger, more 47mm than 40mm. But photos can tell lies
Hi all. It is a 70 cc kit. We are going to try again, we are presuming it's the oil that's the main problem with it being a 70cc kit and what not, the two lines that should line up for the oil pump weren't lined up and in its lifetime it wasn't properly serviced at all so we did a full service, changed a couple of parts, adjusted some adjusters and hopefully it'll be better this time round. I ran that kit in for 300 miles keeping it below 30mph and after those 300 miles i was still gentle with it for 200 miles or so. As said, it had plenty of time to warm up before each use. Now we are doing it ourselves ill be more willing to take responsibility if it buggers up again . This time round as well as a properly adjusted oil pump well add a small amount of oil in with the fuel until we get it right. Also important, I have tried looking into the gear up kits but at this moment I can't get my head around it. I understand the concept (I think) but I'm unsure on what I would need to buy. Also, any thing else that you guys would advise me to buy? Thanks for all the help so far
your scooter has a set of gears in the rear of the engine case that drive the wheel. theres usually a set of four gears , two primary gears and two secondary gears. think of a pushbike you have 2 cogs at front and two at rear the first cog is a 41 tooth with a chain onto a 13 tooth , when you pedal you can only pedal so fast before your knackered out. if we changed gears so the cog on he rear was smaller you would go faster. this is what a secondary gear up kit does, when you turn your rear wheel a full rotation the clutch bell rotates a certain number of times lets say it turns 7.4 times, when you install a gear up kit and do the same thing the ratio changes and that full turn of wheel makes the clutch bell rotate 10.5 times. it means your gear ratio is higher and that means a higher top speed. Pedparts ( google search) has a selection of gear up kits for the NRG power / MC3 , most will need you to press a gear cog off your stock spline shaft and replace it with a bigger tooth gear, but Jasil do a 3 gear kit tahts already pre pressed all you have to do is fit the three gears and shaft into the gearbox with your stock 13tooth shaft ( no need for a large press to do the work its done for you )
The oil is Motul's Scooter Power. And thanks, I've had a look and will purchase it as soon as possible
Ah, sorry, I am pretty sure that it was the same problem. We don't have pictures as we told the local bike shop to fix it and sort it and they said they would. I expect the previous owner hadn't serviced it in the 9000 miles he did, and then as the poster above says he probably thrashed it with the 70cc on until it died. We are going to do all our repairs our self from now on, my dad restores/repairs classic/modern cars so yeah, that is the plan and hopefully it's alright. We have life again by the way, new piston and cylinder is on, so thanks to all of you for the help! Will hopefully, with the new knowledge via the instructions etc, it can keep going this time. Will buy a gear up kit when possible, is there anything else?
anything else ! , yup just dont abuse the new kit lol. gear up will help stretch the motors legs somewhat and give you a little better top end with the the taller ratio ( 70cc kits can pull gear up kits but a stock/derestricted 50cc will struggle ) so its a good upgrade to go with the new kit.
