PUCH MAXI – DEFINE THE RIGHT SPARK PLUG
HEAT RANGE

Tags: sparkplug, headrange
Author: Thomas R.

On this page we will discuss how you can define the right heatrange of your Spark Plug for Puch Maxi Mopeds.

DEFINE THE RIGHT HEAT RANGE

Defining the right heat range of your spark plug is essential for the good performance of your Puch Maxi. The general rule I love to use is, the more rolls per minute, the colder the heat range needs to be.

Which heat range your current spark plug has, is always mentioned on the spark plug. However, each manufacturer uses it’s own way of defining the heat range.

In case of the NGK spark plugs, the rule is:

the lower the number; the hotter the heat range
the higher the number, the colder the heat range

In case of the spark plugs of Bosch, it’s the other way around:

the lower the number, the colder the heat range
the higher the number, the hotter the heat range

PUCH MAXI HEAT RANGE TABLE

After doing a lot of research and asking a lot of Puch experts their opinion, we created a short tabel with the type of cilinder, the heat range, the brand and the indication mentioned on the spark plug. This will help you a lot to define the right heat range of your Puch Maxi.

Cilinder	Warm / Cold	Heat Range	NGK	Bosch
50cc	Warm	5	NGK B5HS	Bosch W8AC
50cc fast	Warm Normal	6 7	NGK B6HS NGK B7HS	Bosch W7AC Bosch W5AC
60-70cc	Normal	7	NGK B7HS	Bosch W5AC
70cc fast	Cold Cold	8 9	NGK B8HS NGK B9HS	Bosch W4AC BOSCH W2AC

IS THIS REALLY THAT IMPORTANT?

Yes! To show you the importance of it, I will share you my own experience.

A few months ago my Puch Maxi was having troubles at full speed. When I was driving at full speed, my Puch maxi made a ‘stuttering’ sound. Really bizar and probably not good for my beautiful lady.

This was during summer and autumn. When winter arrived and the temperature dropped significantly, my Puch Maxi didn’t even start anymore (drama!). This came as a big surprise, because my lady always started in a few seconds. So I tried several things… But the problem only disappeared when I defined the right heat range and I changed the heat range of my spark plug. And guess what, my Puch maxi didn’t start because of the fact that I was having the wrong heat range! I replaced it with a Bosch W8AC (which is a warm spark plug) and it started immediately. In addition to that, the stuttering at high speed was also gone. So yes, to define the right heat range is important :-).

Don’t be stupid, do the investment

After doing a lot of research, I noticed that a lot of people experienced serious damage to their engine because of not using the right heat range. So don’t be stupid and spend of a few euro’s / dollar’s on the right spark plug and avoid this kind of trouble now or in the future. If you define the right heat range of you spark plug today, I can guarantee you that you will avoid a lot of trouble later.

common problems and solutions

Here we will discuss some common issues and how to solve them. If you have an issue that needs to be solved, send us an email to thomas@puch-mopeds.com