Q: I’ve just bought a Yamaha BWS, 2006 model, with 30,000km on the little clock. I’m very happy with it but recently I decided to clean the air filter because of the mileage.
It was indeed very dirty so I cleaned it, oiled it, and washed out the air box, which is a standard one. But now the scooter has become sluggish and oil is dripping out of the air box! So should I now replace the filter for a new one?
Pierre De Wet
A: The stock filter is a paper element and therefore requires no oil. So if it is you’ll have ruined it and it will certainly need a new genuine Yamaha replacement, which aren’t too expensive. After fitting it the stock performance will return.
Also, screw the airscrew in and back out one complete turn, which seems to give a better pull-off in stock trim. You might have to raise the idle a bit to compensate. Give that a try as well?
Q: Hi guys and I hope you all have a great holiday because I’ve enjoyed your site all year so keep up the good work in 2019, I’m sure you will?
Anyway back to my question. I own one of those Honda FMX 650 Supermoto fun bikes from around 2007, I believe. I’ve owned the bike for many years and it’s never given me any problems. However, it’s covered in a ‘thousand’ pipes surrounding the engine in the name of reducing emissions I suppose, and I like to take them all off.
I’ve been told this will increase power and living in Jo’burg, at altitude, it also needs a jetting change because the plug seems to run ‘black’? So is this correct and what sort of jet sizes should I be running to get a bit more power from this old 644cc single? The bike also runs the stock air box and exhaust (filter is clean), in case you’re wondering.
Thanks for your time and don’t get too ‘hammered’, which I’m sure you will.
A: We’ve taken all this emission pipe work garbage off before and on the dyno it makes no difference at all to improving power output. The only advantage there is it tends to save a few kilograms of weight. So we wouldn’t bother unless you desire a less cluttered engine to look at?
Regarding jet sizes we tend to drop the size by around 7 to 8% for our 1500m altitude. So take out the main jet and see what the size is, it will have it engraved/stamped on it, and drop accordingly. We also recommend some sort of less restrictive exhaust because the stock twin cans are also very restricted for emission control. They could also affect jetting so try to do that first and check the plug colour as this could lean the bike off considerably.
Hope that helps and thanks for the comments and have a superb holiday too.
Q: My girlfriend owns a pristine Kawasaki z800, which I’ve obviously become a full-time mechanic for. But I’m not writing to moan about ‘mechanical’ relationships.
She keeps on complaining, that sometimes, the bike won’t start when she puts it into gear before she pulls off, excuse the terminology. I’ve ridden the bike myself but everything seems to be OK from my side. So before we have another argument I thought I’d ask you guys with your wealth of knowledge first?
Hopefully you know of something that can cause this so I can have a more peaceful life?
A: Well this is an easy fix and it’ll more than likely be the side stand switch, as they do tend to give problems on this model and on the z1000 as well. Make sure the wires are connected properly, and maybe try a spot of lubricant on the plunger/stem that the side stand pushed onto first, as well.
Either buy a new one or join the two wires leading to the switch together and see if that cures the problem first. Then we can guarantee that you’ll have a more peaceful life – maybe?
Q: I’ve owned a KTM 1190 Adventure for few years now with very little problems, until yesterday. I went to the shop with the bike running fine but when I came out and started it there was just a loud ‘crack’ noise and the engine locked solid.
I’ve heard of scary internal things but I thought I’d run it past you guys first, before I take it to a dealer with a predictably large invoice afterwards.
Just a short simple letter and I’m anticipating a quick reply please?
A: Well here’s a quick reply and I’m afraid it’s very bad news. It sounds like one of the automatic cam chain tensioners has broken, which will cause the cam chain to ‘jump’ a tooth, or two, that’ll certainly lock the engine solid. This can also, easily, crack the cylinder head or some of its components around the head.
The only thing you can do is to locate and dismantle the cylinder head that has locked up. Obviously this isn’t going to be a cheap exercise I’m afraid. If you search around the Internet you’ll find many 1190 owners actually convert their bikes to manual cam chain tensioners due to this problem found on some 1190. So you might want to look into that conversion for the future and where to obtain them?