125 down on power?

[adengtg]

Right then, ive noticed that my bike used to get around 60-65mph flat out but as of lately the power seems to have dropped significantly.

Ive been getting as low as 40mph flat out sometimes and a maximum of about 50mph. i haven't noticed anything different about the engine but i have had electrical problems which are now sorted so maybe that has something to do with it? Its a lexmoto adrenaline so i wouldn't think the electronics would be an issue as they're as basic as they get but i'm no expert.

Its got an ebay Chav-can on the end and 32-51mm link pipe on it so maybe that could cause it? ive also replaced the throttle cable myself which could have fucked with the carb but then it was still down on power before that.

I know theres not much you can do for a 125 in terms of power but 40mph flat out is really taking the piss. went out with a guy on a bone stock KTM RC125 and he was absolutely flying compared to me. actually thought he was on the RC390 at first!

Any advice on what to check/what it could be? Or any advice on how to give it a little extra power? (in the process of trying to find a carb jet and filter for it but no luck yet)

Thanks for the help.

[stephen_o]

Non Standard cans can cause power loss and heavier fuel consumption because they alter the fuel mixture.

It is more likely that in replacing the throttle cable that it hasn't been adjusted right - try checking that before you start messing with carbs etc because once you mess a carb up your in for a right ballache.
____________________
current scoot 2009 Yamaha YBR250 + Current Pootle 2013 Nissan Leaf

[adengtg]

[stephen_o]

Ok so it isn't going to be the new cable and they should be grabby. Check Oil and change, have a look through the old oil and see if you can see any metal. Check Air Filter and clean or change. Check spark plug colour and gap and alter or replace if needed.

Those are the bare basics that need doing - don't touch the carbs until you have done these.
____________________
current scoot 2009 Yamaha YBR250 + Current Pootle 2013 Nissan Leaf

[adengtg]

[adengtg]

[Rogerborg]

What colour was the plug tip?

Unless the bike is actually missing at high rpm, then either the fuelling is off, or it's lost compression.

Plug tip will give you some clues to the former. The latter is going to need a compression tester.
____________________
Biking is 1/20th as dangerous as horse riding.
GONE: HN125-8, LF-250B, GPz 305, GPZ 500S, Burgman 400 // RIDING: F650GS (800 twin), Royal Enfield Bullet Electra 500 AVL, Ninja 250R because racebike

[kgm]

Maybe not what is causing the issue but the throttle should not be grabby. It should open smoothly and snap shut smoothly without any binding. It should also have a little free play. Did you fit the correct size cable?

[stephen_o]

Ok, Good start in changing the plug but If by deep cleaning the bike you meant you washed it and dried it then thats totally unneccesary at the moment. One of Teflon Mikes oft stated points is don't kill your bike with kindness and he is spot on, It is more important to maintain the mechanics of the bike rather than cleaning it. A clean bike with an unserviced engine still runs like a dog.

At this point DON'T throw your old plug away, keep it safe incase you continue to have problems. You need to check and probably change the oil and check and clean the air filter.

Do you have an owners handbook to tell you where the air filter is? Poor running at speed is often a sign of a blocked air filter - running at higher revs means the engine needs to pull more air through - a blocked filter means it cannot and the fuel mixture becomes to strong which leads to poor running.

What colour is the tip of the spark plug that you pulled out? that gives a massive clue as to the state of the mixture and the engine.

I will try and find a chart online and post it here in a min.
____________________
current scoot 2009 Yamaha YBR250 + Current Pootle 2013 Nissan Leaf

[stephen_o]

check your old plug against this
____________________
current scoot 2009 Yamaha YBR250 + Current Pootle 2013 Nissan Leaf

[stevo as b4]

What kind of fucking idiot would want to try and tune a knackered/ down on power engine for more power?

I guess OP didn't mean this but was just desperate for an answer to make the bike work correctly in 100% standard form?

[adengtg]

[adengtg]

[stephen_o]

GPS speedo is far more accurate than any car or bike speedo, if your gps was reading 62 then the bike would poss be reading 67mph which for a 125 is as good as you will get.

Chain lubing and brakes

You probably did have the wrong spark plug in before, differences can be minor, I can't check against the chart right now so I will report back but keep the plug in case the new one fails and at least you have something that will get you out of trouble.

You need to find and clean the air filter and at least look at the oil and change it.

I looked on the lexmoto site which led me to a chinese motorbikes site and when I tried to find out about servicing the site said refer to the owners handbook.

Do you have a owners book?
If not did you buy the bike from a dealer? if so go back to them and ask for the handbook - I think it is actually a legal requirement for them to give you a manual. Also did you get a tool kit with the bike?

How long have you had the bike and how many miles do you think you have done?
____________________
current scoot 2009 Yamaha YBR250 + Current Pootle 2013 Nissan Leaf

[stephen_o]

Looking at the plug pic I think it looks "overheated" which means the mixture is too lean which would also I think be right with a chav can on or a blocked air filter.

Hopefully some others will give their opinions.
____________________
current scoot 2009 Yamaha YBR250 + Current Pootle 2013 Nissan Leaf

[adengtg]

[stephen_o]

Oil on motorbikes needs changing more frequently than cars. You absolutely* need to change the oil and filter, or clean the filter if thats what the sheets say. You need to clean the air filter. It will make a difference. I do not believe at all that you need carb jets, you have the wrong exhaust on the bike which can cause worse running because the throughput of air and combustion changes.

An overheated spark plug could be a sign of the engine having insufficient oil so keep an eye on it. Hopefully for you there is no lasting damage.

* as you have topped the oil up, check it again next week and what colour is it? you saw the colour it was in the bottle, if it is BLACK as coal in the bike then the oil is spent and needs totally replacing - this is normal routine maintenance and the bike is due for it.
____________________
current scoot 2009 Yamaha YBR250 + Current Pootle 2013 Nissan Leaf

[adengtg]

[stephen_o]

I have just checked my manual for my YBR, the oil should be changed every 1000km so your way overdue for that. You may not be burning oil - you do use some, as I said its way overdue. Change it tomorrow and then check it next week to make sure it hasn't dropped.
____________________
current scoot 2009 Yamaha YBR250 + Current Pootle 2013 Nissan Leaf

[Pjay]

RPM is key here. In say third gear does the bike redline as usual?
If the engine can redline, it shows something more sinister causing the top end to drop off that much.
____________________
struan80 - I'll go first - satisfied tick 1

[redeem ouzzer]

My God OP is fucking thick.
____________________
Be a REAL MAN!

[Rogerborg]

[BusterGonads]

[adengtg]

[adengtg]