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Post by rhinebeck on Aug 29, 2013 16:46:48 GMT -5
Hi everyone,
I finally registered after lurking in the previous site and now this one.
I have a question that hopefully can be answered …
I own a very nice 2008 SYM RV250 that I bought two years ago. It has a bit over 5,000 miles and I am the 2nd owner.
The original owner bought it new for his wife,
between the two of them, they only put 304 miles on it.
She thought it was too big and he was a motorcycle guy. That’s why they were selling it.
I did all the things you should: check & tighten nuts/bolts, change oil, gear oil
coolant, air filter, add Seafoam, run the gas out, refill and add more Seafoam etc.
It is an amazingly fast, comfortable and smooth scooter and I am very pleased with
it even though the closest SYM dealership is now 400+ miles away.
My problem:
It always starts and runs on the first try. It runs great for the first few miles, then when I stop at a light it stutters when I start off again.
I ‘feather’ the throttle and it takes off and rides like it’s brand new. When warmed up, every red light has the same effect -really bogs down, then sails right along.
I rode it to Harbor Freight and spent about 30 minutes there, (I love poking around in there), when I came out, (I was dreading the ride back home because of the way it was acting up), it fired right up and ran like new even at red lights.
I changed the gas filter but that didn’t help any. This week it has added quiet backfiring, (little pops) to it’s act.
It might be time to change the air filter again. I didn’t check that because it is an hour-long PITA job because of the plastic you have to remove.
Is it time to check the valves?
Well folks, any idea what it might possibly be?
Thank you in advance. Regards.
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Commuting is the best part of my day!
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Post by trailheadmike on Aug 29, 2013 17:21:47 GMT -5
I always start with small things first. Sounds like you could be lean and will need to adjust the air/fuel mixture. When you start up the enricher is on so you don't have a problem. When the engine warms up the mixture leans out, and it might give you the problem. Easy place to start checking.
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Post by alleyoop on Aug 29, 2013 17:25:59 GMT -5
That sure sounds like the classic case of tight valves and usually it is only your exhaust valve that is tight and once nice and hot it is not closing all the way and it is loosing compression. When this happens they will not hold idle and to keep them running when you come to a stop you have to keep on goosing it a little otherwise it will die. It will get worse then they may not even start when cold or be very hard to start when cold after the Valve cools and it is now open and not closed.
Alleyoop
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Commuting is the best part of my day!
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Post by trailheadmike on Aug 29, 2013 17:29:37 GMT -5
In alleyoop we trust.
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Post by shalomrider on Aug 29, 2013 18:11:32 GMT -5
howdy, i don't remember if those are carburated , but if so it also could be the idle jet plugged, thus after coming off idle it runs fine.
lotsa miles and smiles to ya
ken
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Post by rockynv on Aug 30, 2013 4:16:04 GMT -5
At 5,000 miles it is most likely time to check the valves. If you have been keeping up with fuel treatments then before you go crazy tearing up the fuel system looking from gremlins get those valves adjusted to spec.
If you change jets or readjust the carb first and do the valve adjustment after, chances are that you will have to reset the carb back to where it was originally once you get the valves adjusted and the engine breathing correctly again.
You may want to consider stepping up a grade on the gasoline too as using too low a grade of fuel can accelerate the speed at which the valves sink into the seats especially if the compression on the Sym is above 9.1.
Also verify that the spark plug boot is screwed onto the plug wire completely and that you have a nice fresh properly gapped spark plug. Both can cause engine skip issues once things warm up.
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Post by rhinebeck on Aug 30, 2013 7:27:56 GMT -5
Hello all,
Thank you for the quick, friendly replies!
I adjusted the valve on my Genuine Buddy 125 a few years ago, so it will not be a completely foreign thing to me.
The SYM valve is probably a bit harder to get to, but it has such a long and wide seat/storage compartment, that when you
remove it, you have access to a very open engine area.
We are in Florida, so I will tackle this in a few weeks when the temp starts to drop a bit.
Again, thanks to all that replied.
Regards.
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2008 Roketa MC54B 257 (10,000 miles and climbing)
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Post by bhinch on Aug 30, 2013 16:28:33 GMT -5
Hi....after the valves are adjusted, then you can adjust the idle. Trust me, I have over 10,000 miles on my scoot and the valves have been adjusted only once. Still running strong...Life is Good...
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Post by teskow on Aug 30, 2013 19:47:42 GMT -5
I set my valves a bit loose then the recommended tolerance. Is there a downside to this other than a bit clicking valve lash noise?
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Post by alleyoop on Aug 30, 2013 20:13:10 GMT -5
If they TICKY TICKY TICKY that is good then you know that are not tight(I little loose valve is a happy valve). If they CLATTER CLATTER CLATTER then they are to loose and you will loose some power.
Alleyoop
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Post by skuttadawg on Aug 30, 2013 23:23:45 GMT -5
All 4T engines will need the valves adjusted at least once with some needing it out of the crate . Too tight can make it hard to start , stall or no start when warm and in extreme cases no start at all . My Echarm they got loose around 2,200 miles . It started and run great , but would want to to stall just before coming to a stop unless I gave it some throttle . I am now at 17,600 miles , it runs great and I have only changed the oil with no more touching the valves .
SYM is a good brand as a member posted having thousands and thousands of miles on the stock engine
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Post by wild1banana on Jan 12, 2020 0:21:24 GMT -5
I had the same problem with my 2009 Sym rv250 with carburetor and replaced the auto enricher solenoid and cleaned the carb and it runs fine now. The auto enricher would not extend to lean the fuel mixture after warmup and the mixture would be way to rich and the spark plug showed it was foul from to much gas a black wet plug. When the plug is fouled from running to rich it will carbon up and the engine will die. I changed the carbon sparkplug and replaced the auto enricher solenoid.
Installed rebuilt carburetor with new enrichment solenoid and road tested scooter and was pleased with its immediate startup and warm running smooth engine performance and great gas mileage. This is a great Scooter and found it handle nice and handled freeway speeds with ease. Great machine
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..BAD TO THE BONE..
