Lacking power

[Gareth123]

My GL145 seems to run poorly after running at 100km/h for more than 20 mins. This sorts itself out when I leave the bike to cool down for an hour or so.

It feels like it has less acceleration.

Does anyone have any ideas?

Also it has missed occasionally while accelerating hard. Doesn't do it all the time though.

Any suggestions would be appreciated.

[CookMySock]

Sounds like it's getting too hot coz the poor wee thing is overworked. How much do you weigh, how fast are you travelling, and how much throttle are you using?

Steve

[Sparrowhawk]

I had a similar issue after about 30 mins of motorway riding. Turned out there was an aftermarket in-line fuel filter, that was clogged. It didn't help that the dork that installed it had used standard rubber hosing to connect it, and the fuel was persishing it.

Have a look to see if there's a fuel filter on your bike, and then have a look it, and remove or replace it.

[White trash]

20 minutes + @ 100kays on a fucken GL145??!!

Have a heart man, the poor little thing's just tiring of it's constant anal raping. Give it a break,

[nsrpaul]

2nd that

[Gareth123]

I only weigh 66kgs. 100km/h is about 1/4 throttle when I'm on it.

I do have a fuel filter on my bike. I'll have a look at it tomorrow afternoon.

[CookMySock]

I only weigh 66kgs. 100km/h is about 1/4 throttle when I'm on it. I do have a fuel filter on my bike. I'll have a look at it tomorrow afternoon.

Ok you're not a fatty then. I agree about the fuel filter, but you might be askin a wee bit much from the poor ol' dear.

Steve

[xwhatsit]

No way! It should be happy to sit at that all day. It's an aircooled single.

I'm no genius, but it could be overheating if it's a bit lean or the timing is not perfect. Doing the valve clearances could be a good idea too, if they're not enough when it's getting nice and toasty they might not be fully closing. Fuel delivery could be an idea too, if there's not enough flow rate from the tank, or a blocked breather, but 20 minutes seems longer than what those things usually crop up at. Bad seal between carb and cylinder head?

20 minutes being thrashed is nothing, really. Little 50s put up with it quite nicely. As you said 100kph isn't even really pushing it too hard. Don't listen to the people with an excess of horsepower. Aircooled Honda single should take full-throttle abuse all day and not complain.

[Gareth123]

Checked the fuel filter, it was clean the flow seemed to be fine. I checked the spark plug and it was okay. It didn't look white. I did top up the oil by about 300mls. I'm sure that will make a difference.

Haven't had the chance to check the seal between the carb and the cylinder head yet, I'm not 100% sure about what I'm looking for. Any tips?

[steve_t]

What fuel are you running? You might be getting preignition/knock which could cause the higher temps that would only get worse over time. Might be better on a higher RON fuel

[xwhatsit]

Haven't had the chance to check the seal between the carb and the cylinder head yet, I'm not 100% sure about what I'm looking for. Any tips?

Well the way I checked it was to get the engine really toasty hot and cooking, in its `losing power' mode. Then grab a can of carb cleaner and spray it every which way around the boot which connects the carb to the head, in particular aiming for the seam between the two. If it's leaking at all, you might see bubbles or the carb cleaner getting sucked in, and it might change the engine note or produce some smoke. If there's no change, then there's probably no leak.

[CookMySock]

It might be too hot a sparkplug. If the electrode is too hot, its' hot glowing tip will ignite the fresh incoming charge before it can even finish its' inlet stroke - there will be little or no detonation since there is no compression stroke.

Go down a plug-temperature range and try that.

Steve

[Gareth123]

Well the way I checked it was to get the engine really toasty hot and cooking, in its `losing power' mode. Then grab a can of carb cleaner and spray it every which way around the boot which connects the carb to the head, in particular aiming for the seam between the two. If it's leaking at all, you might see bubbles or the carb cleaner getting sucked in, and it might change the engine note or produce some smoke. If there's no change, then there's probably no leak.

Cheers for that. I'll do that next time I have a day off and the desire to see my girlfriend

It might be too hot a sparkplug. If the electrode is too hot, its' hot glowing tip will ignite the fresh incoming charge before it can even finish its' inlet stroke - there will be little or no detonation since there is no compression stroke.

Go down a plug-temperature range and try that.

Steve

I didn't even know spark plugs have temperature ranges! Guess you learn something new everyday.

Would dropping down a temperature range affect the bike when just commuting through town or will it not make a difference?