Q: Hi guys. I’ve just written this message late at night because I’m really getting annoyed and, asking for help.

I’ve just bought a used Big Boy pit bike (125cc), that didn’t run when I bought it. I’ve replaced the spark plug, installed a new air-filter and changed the engine oil. The plug does have a ‘spark’ when I kick over the engine, so it’s not that. I’ve also taken off the carb and cleaned it to perfection as the jets were blocked with old, and sticky, petrol.

But it still won’t start and the engine seems to have good compression. Have you any ideas what I could look for next?

Kyle.

A: Yes we can advise and it’s an easy thing to check. Take off the two small valve covers on top of the engine and check the tappets for free play. They’re easy to adjust and you only need a 9mm spanner and pliers to hold the top of tappet.

You’ll need to find ‘feeler-gauges’ as well and set the clearance to 0.15mm between the tappet and the top of the valve stem. Once set turn the engine over a full cycle and check again.

This is a common fault if those bikes don’t start. So that should take away your anxiety.

Good day Bill,

Thank you for the entertaining and informative review on the Gixxer 150! Love it! I had my eye on this bike for a while as a first bike for my wife. Your review came in the nick of time and I took the plunge.

In your review of the bike, you noted the possibility of tweaking the carb jetting, and also getting clever with the gearing. Could you possibly direct me to someone capable and knowledgeable who’d be able to assist me with such options without messing up the bike? I’m certainly not an expert on this, but I do know you don’t want anyone just fiddling with these aspects of your brand new bike.

I appreciate your feedback! Keep up the good work!

Regards,

Anton Potgieter

Hi there, and thanks for the kind mail - hope you 'both' enjoy the 150 as much as we did.

If you live in Gauteng give our Dyno specialists a call, he'll know what to do? His name in Noddy (084 430 9090). 

Have fun...

  Bill Hunter

Hi, Noddy here from www.bikeworx@icon.co.za and I just thought you guys would like to see these, which we weighed the other day?

The carb’s weighing in at 4.5kg are from a 1978 Honda CB550, which are quite heavy to say the least. The carb’s weighing in at 2.9kg are from a mid 1990s Honda NC23.

Quite amazing how 1.6kg have been shaved off, and that’s including the bell-mouths. Just though it’d be interesting to show how the constant quest for saving weight happens with every part of the motorcycle.

Noddy.

Thanks for that and if any of you have similar things to show us please mail Bill, at the email address at the top of the page...

Hi guys…

I’m not asking a question about my bike’s problems, instead I thought I’d tell you about a recent issue that I managed to fix.

I have a Royal Enfield 500 Bullet that broke a piston ring and subsequently damaged the piston irreparably. After many calls and searching throughout South Africa I could not find a replacement piston, which was irritating to say the least.

After a few beers in the pub, with piston in hand, my friend said he thinks he has one that looks very similar and might work. He owns a car spares store in Pretoria. So the next day I took it to him at the shop and he pulled out a piston from a brown paper bag.

To my surprise it was 99% identical except it was 1mm wider in diameter. So I took him the barrel, as it has plenty of ‘meat’ in/on the liner, and he bored it out to fit the piston with the correct clearance. I then put the bike back together and it has now ran perfectly for over a 1,000km.

The piston came from a Toyota Cressida and cost R350. Now how cool is that and I thought it would make an interesting article for your site.

Piet Stobaart.

Now that’s very interesting and thanks for your time and effort to let us know, and our readers too if they have the same problem. Well done.

Bill Hunter