Q: Hi guys. I’ve recently bought myself a Suzuki 1250 Bandit, which is a 2010 model. Everything is cool with the bike because it’s only covered 16,000km and it looks like brand new and it was completely standard.

But that’s now changed because I just fitted a Yoshimura slip-on silencer replacement for the stock fat, heavy and bloated thing, just because I wanted my big Suzuki to sound like it should.

It certainly worked because it sounds fantastic and I’ve also lost a lot of unwanted weight in the process, but…

It now has a very annoying ‘fluffy’ flat spot at the bottom end, which can be an issue whilst riding through traffic, however the top end power seems to be better so I’m happy with that.

So Mr. Noddy, what can I do to get rid of that flat spot, seeing as you seem to be the fueling expert and all fuel injected bikes? Thanks for your time in advance.

Hilton Middlehurst.

A: The easiest way to cure that, because it’s made the Bandit run a little lean at the bottom end, is to fit a Power Commander or the like and set the fueling correctly for our altitude. But that’ll cost you at least R6,500.

Otherwise, call around the Suzuki dealers in Gauteng to see if they have a Yoshimura interface device that’ll connect into your ECU, many have. They should then be able to adjust the fueling to take out that flat spot and it’ll save you money as well. Then I’m sure your Bandit will fine.

Q: My Honda VFR400 has suddenly developed a loud rattle that seems to be coming from the front cylinder head, because as you know it’s a V4 and therefore has two cylinder heads.

I took off the fairing and had a good check around everything I could see, just to see if something had broken and/or fallen off, but found nothing. The rattle was most certainly louder when the fairing was off though.

So I’m a bit worried if something terminal has happened because my VFR has only covered 52,000km over the past ten years or so, and an official Honda dealer has always serviced it at the correct intervals. 

So of course I would like to know if you’ve had a similar problem before and if so what was it?

Regards.

David Edgecomb.

A: This sounds to me like a simple cam chain problem and with 52,000km on the clock it’s probably about time to replace both chains for both the front and rear bank of cylinders. However with the rattle suddenly appearing it’s more than likely to be the cam chain tensioner that’s at fault here. It could have stuck/broken and now doesn’t force the blade onto the cam chain anymore or the spring has broken. Either way I’d pull that out first to check it out.

Q: I’ve tried everything I can to get a 2006 Yamaha YZ250F running and absolutely nothing seems to work. It has compression because it’s a bastard to kick and I hate it!

So if you could please send me any thoughts on this irritating matter I’d be grateful forever. It’s had a new plug and the air-filter is super clean, so it’s neither of those.

So come on Billysbikes, help me out before I burn the thing to the ground?

Corbus

A: These are very temperamental bikes, especially with the age it is now. But I’d try out these suggestions and to be honest you need another bike of the same to swap over the parts because this is a simple case of elimination, or not so simple in this case.

Inside the head are two cams and the retaining bolts for the cam sprockets might have come loose and the timing has slipped/moved. So you can check that yourself.

It could easily be an ignition problem but this why you’ll need another YZ250F to swap over the ignition module instead of just buying one and it doesn’t cure the problem. It could also possibly be the throttle position sensor on the left side of the carb – if that’s broken it’ll never start. So try to find one of those to swap over as well from another YZ250F that does start.

Good luck because these old MX bikes can be a right pain in the arse, but they do make a nice fire…

Q: I’ve recently got my wife/girlfriend/spouse or whatever into motorcycling after 30-years of being together, we’ve now both just turned 60 and loving life more by the day. So don’t worry about getting old, life still goes on the way you want it to.

Anyway, I didn’t want to buy her a modern bike because I don’t understand them and I ride a 1980 Honda Goldwing anyway. So I found her a late seventies Suzuki GS550 E, which is in fairly good condition and has 73.000km on the speedo.

When we got it home we realized that it doesn’t run, as it should. So I set the points and fitted new plugs and air filter because I know how to do that and flushed the carbs through which improved things a little, but we still weren’t happy.

So a friend of mine came over with a compression tester and it revealed that two of the cylinders (1 and 3) was low compared to the others. The bike doesn’t smoke while it’s running so we think it could be the valves and not a piston problem. So my question is, do think it’s the valves also and will it be a problem to fix them – have to get the wife on the road ASAP?

Arnold Cummings.

A: It sounds like you’ve eliminated most things already and these older bikes are relatively easy to work on so that’s not a problem here. So I would certainly now check out the valve clearances because that can easily cause a compression drop, and maybe they haven’t been checked after many years of use.

You’ll have to take off the cam cover and I’d make sure you’ve a new gasket for this first, which a Suzuki dealer or aftermarket parts dealer will be able to get for you. Once inside turn the crank over and check the gap for each of the eight valves with a feeler gauge and set them between four to six thou’, some people set them four on the inlet and six on the exhaust. If they’re too tight, which I expect they are, you’ll have to change the shim size accordingly, so it might be best to take it to a Suzuki dealer who has the different sized shims in stock, otherwise you won’t be able to complete the job.

Then once all the valve clearances are correct and within specification check the compressions again, and again after you’ve ridden it for a few hundred kilometers to let the valves ‘seat’ again, I then believe things inside your motor should be much better. Hope your wife/spouse/girlfriend enjoys her new ride?