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Post by Schlappy on Feb 15, 2019 18:51:43 GMT -5
I own a Genuine Roughhouse 50 sport (May 2016)
It has 14550 miles on it, de-restricted from day one, really babied it for the first 600 miles, been meticulous with oil changes, belts, roller weights, spark, etc and other maintenance.
But, it's top speed had dwindled. Can barely reach 30 mph on the flat compared to 40+ mph top speed it used to do. Recently had a garage replace the cylinder, head, piston, rings, (essentially a stock replacement kit), and was informed that the crankshaft has 'some' play in it, but didn't think it warranted replacing.
What might it really take to get it's zip back or is this kind of thing just the nature of the beast ?
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Post by ryan_ott on Feb 15, 2019 19:38:52 GMT -5
WELCOME!!
If your up on maintenance, belts, rollers etc and the speed didn’t come back with the new cylinder I think your exhaust may be restricted due to carbon build up. I’ve seen posts of stock Yamaha 50’s going for 20-30,000 mi. The shop should of checked if the rod play was within spec but even new cranks have some play.
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Post by repherence2 on Feb 15, 2019 20:38:28 GMT -5
Worn belt?
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Post by SMALL CC TEK on Feb 15, 2019 22:50:29 GMT -5
14,500 miles . You ever service it ? Like a new plug clean air filter fuel filter gear oil just a basic service . Did you derestrict it yet ?
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Post by benji on Feb 16, 2019 6:50:05 GMT -5
I agree on the pipe being clogged. Or maybe. The new "stock replacement" cylinder has different porting and you need to retune the cvt. If swapping an oem bore out for another oem bore, don't buy the cheapest one around. Get an actual oem bore or you could lose power. For instance, the difference between the porting on a stock jog 49cc bore was better than a random Chinese 70cc bbk I had. The bbk BARELY had more top speed. If it was a Chinese 49cc bore I bet it would have half the power of the oem Yamaha 49cc bore.
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Post by benji on Feb 16, 2019 6:51:59 GMT -5
I've seen a zuma for sale with 40,000 miles. What did the oem Bore look like? Was it scuffed or damaged at all? It still may be good...
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Post by ryan_ott on Feb 16, 2019 9:09:51 GMT -5
I agree on the pipe being clogged. Or maybe. The new "stock replacement" cylinder has different porting and you need to retune the cvt. If swapping an oem bore out for another oem bore, don't buy the cheapest one around. Get an actual oem bore or you could lose power. For instance, the difference between the porting on a stock jog 49cc bore was better than a random Chinese 70cc bbk I had. The bbk BARELY had more top speed. If it was a Chinese 49cc bore I bet it would have half the power of the oem Yamaha 49cc bore. You mean like this:   |
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Post by geoffh on Feb 16, 2019 9:15:51 GMT -5
Nice looking scoot,a drop in speed indicates something amiss ,usually a simple fix but it,s a long list of stuff to check to get there,at 14k my Yamaha jog was ready for a new belt,I don't,t see it mentioned much but wrongly inflated tires have a massive effect on these little scoots.
Geoff
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Post by aeroxbud on Feb 16, 2019 19:32:02 GMT -5
If the cylinder was replaced with a cheap Chinese one I might be concerned. Some of these eBay kits only make stock power when fitted with a sports pipe the porting is so bad.
A coked up exhaust might be a good shout at your mileage. You can sort them, but much easier buying a new pipe. The next R pipe on my slider got noticeable slower as it got older, with carbon build up.
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Post by Schlappy on Feb 19, 2019 0:40:36 GMT -5
Thanks for the info guys. Aye it didn't occur to me the pipe might have clog and or buildup. The pipe is relatively new, less than 2 months old, but a symptom I was having was sandy debris and oil leaking from the pipe, which cleared up after the cylinder/piston swap, gotten from ScooterTuning.ca where the sales rep assured me it was a stock replacement. I have replacement clutch assembly and variator kit coming my way soon, after inspection of them suggested belt slippage.
Would it be hazardous to take a gallon of 2 year old gasoline I have and flush the pipe with it in hopes of loosening carbon or more of that sandy gravel from the inside of it if that's the case? Or is there a better way.
Your insight is appreciated.
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Post by bungee36 on Feb 19, 2019 4:44:13 GMT -5
Thanks for the info guys. Aye it didn't occur to me the pipe might have clog and or buildup. The pipe is relatively new, less than 2 months old, but a symptom I was having was sandy debris and oil leaking from the pipe, which cleared up after the cylinder/piston swap, gotten from ScooterTuning.ca where the sales rep assured me it was a stock replacement. I have replacement clutch assembly and variator kit coming my way soon, after inspection of them suggested belt slippage. Would it be hazardous to take a gallon of 2 year old gasoline I have and flush the pipe with it in hopes of loosening carbon or more of that sandy gravel from the inside of it if that's the case? Or is there a better way. Your insight is appreciated. I concur, that carbon buildup in the exhaust pipe could be the culprit. I've seen it happen on my former high mileage scooter. Also, the activated carbon "catalyst" material may be clogged or just have fully absorbed all pollutants at this mileage, or baffles may have collapsed. I wouldn't try flushing out with gasoline. Try removing the exhaust and physically knocking out the crap. As a "band aid" solution, I also drilled larger holes at the end of the exhaust pipe, as my catalyst was disintegrating and small, 3 - 4 mm. sized bits of carbon were clogging the stock exhaust on a regular basis. As a short test, could you remove the exhaust pipe and run, VERY BRIEFLY, normally? |
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Post by fugaziiv on Feb 19, 2019 9:44:37 GMT -5
I own a Genuine Roughhouse 50 sport (May 2016) It has 14550 miles on it, de-restricted from day one, really babied it for the first 600 miles, been meticulous with oil changes, belts, roller weights, spark, etc and other maintenance. But, it's top speed had dwindled. Can barely reach 30 mph on the flat compared to 40+ mph top speed it used to do. Recently had a garage replace the cylinder, head, piston, rings, (essentially a stock replacement kit), and was informed that the crankshaft has 'some' play in it, but didn't think it warranted replacing. What might it really take to get it's zip back or is this kind of thing just the nature of the beast ? Glad to see you made it here. This is easily one of the best scooter forums going. Matt |
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Post by jackrides on Feb 19, 2019 11:30:58 GMT -5
I used to take exhaust pipes, baffles out, to a radiator or chrome plating shop to get them acid dipped. Those pipes were clean! Not pretty, but that's another issue.
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Post by pinkscoot on Feb 19, 2019 12:11:18 GMT -5
There are several youtube videos on cleaning an exhaust that don't involve gasoline. Google it and you'll find one. Maybe someone here has a good link.
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Post by geoffh on Feb 19, 2019 16:01:22 GMT -5
If the exhaust is only 2 months old it won,t have a build up leave it alone but check the restrictor ring has been removed,the CVT sounds like the best bet,check the belt for wear and it,s the correct size.
Geoff
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