Jet size identification?

[bakaracer]

YOu dont need to upjet wen you mill the head

Accually you do.when you increase the compresssion,the flow increases in the case and cylinder so a upjet of 1 or 2 sometimes 3 sizes will be needed

[Wheelman-111]

Greetings:

Flow increase there may be, but compression-generated heat surely will increase. Whatever the reason a bigger jet almost certainly will be needed.

[spree-rider]

YOu dont need to upjet wen you mill the head

Accually you do.when you increase the compresssion,the flow increases in the case and cylinder so a upjet of 1 or 2 sometimes 3 sizes will be needed

[bakaracer]

Greetings:

Flow increase there may be, but compression-generated heat surely will increase. Whatever the reason a bigger jet almost certainly will be needed.

That's where a colder plug is needed and higher octane fuel.but upjetting to big to help cooling,your loosing power.that's why I always stress on here about compression ratios and octane of fuel.you can jet it so fat that your just on the limit of it fouling plug just to keep it cool,but if the compression ratio is to high and you don't have a high enough octane fuel and stabil at the temps you need it,its still going to over heat.you should know ,you toasted a few cylinders already due to to high a compression with not enough octane to match.

[Wheelman-111]

Greetings:

Egg-zackly right, Baka-san. There are probably other factors as well, but compression alone generates heat. Colder plug can mitigate, Race Gas can make it sustainable, but who's got access to that stuff. Jetting up too rich loses power for sure, but if you want the bore to survive, it's one option. Keep things under 125PSI or so and all is well.

[bakaracer]

In loco's case,if he mills the cylinder head .030 he will be fine with using 91 or 92 octane fuel and using a 7plug during the cold season and a 8plug when the air temps get above 70deg and upjetting till he gets the right plug color.

[LocoParaHonda]

In loco's case,if he mills the cylinder head .030 he will be fine with using 91 or 92 octane fuel and using a 7plug during the cold season and a 8plug when the air temps get above 70deg and upjetting till he gets the right plug color.

So what's all the business with plugs? Should I be using a different kind of spark plug if I do the mill? As far as gas goes, I always use premium in my scoot, gas is so cheap anyways, I figure why not.

[Bear45-70]

In loco's case,if he mills the cylinder head .030 he will be fine with using 91 or 92 octane fuel and using a 7plug during the cold season and a 8plug when the air temps get above 70deg and upjetting till he gets the right plug color.

So what's all the business with plugs? Should I be using a different kind of spark plug if I do the mill? As far as gas goes, I always use premium in my scoot, gas is so cheap anyways, I figure why not.

The plug thing is to remind people that when hot rodding an engine, you need to run colder plugs than normal because high performance creates more heat, hence the need for colder plugs.

Running premium fuel in an engine not requiring it can cause a number of issues, the least of which is premature plug fouling leading to loss of performance. There is no more energy in a gallon of premium gas than in gallon of regular gas, so running it for a performance increase is myth. The only advantage premium fuel has over regular is the extra resistance to detonation, which with a 7 to 1 compression ratio is nonexistent. It just waste money and is detrimental to good engine performance.

[LocoParaHonda]

The plug thing is to remind people that when hot rodding an engine, you need to run colder plugs than normal because high performance creates more heat, hence the need for colder plugs.

Running premium fuel in an engine not requiring it can cause a number of issues, the least of which is premature plug fouling leading to loss of performance. There is no more energy in a gallon of premium gas than in gallon of regular gas, so running it for a performance increase is myth. The only advantage premium fuel has over regular is the extra resistance to detonation, which with a 7 to 1 compression ratio is nonexistent. It just waste money and is detrimental to good engine performance.

doh! I wonder how much those extra cents have added up to over the years. Just seemed like the best thing to do. Where do you buy plugs? At the standard Schucks they near me they said they only have one standard kind of plug for my scoot. Online somewhere? How are they rated? ie, what should I look for?

thanks

[Bear45-70]

The plug thing is to remind people that when hot rodding an engine, you need to run colder plugs than normal because high performance creates more heat, hence the need for colder plugs.

Running premium fuel in an engine not requiring it can cause a number of issues, the least of which is premature plug fouling leading to loss of performance. There is no more energy in a gallon of premium gas than in gallon of regular gas, so running it for a performance increase is myth. The only advantage premium fuel has over regular is the extra resistance to detonation, which with a 7 to 1 compression ratio is nonexistent. It just waste money and is detrimental to good engine performance.

doh! I wonder how much those extra cents have added up to over the years. Just seemed like the best thing to do. Where do you buy plugs? At the standard Schucks they near me they said they only have one standard kind of plug for my scoot. Online somewhere? How are they rated? ie, what should I look for?

thanks

Have the idiot counter cuties (that's all they are, they know less than nothing about cars or engines, except what the computer tells them and it is wrong at least a third of the time, especially since O-Reilly's took over) order what you want. Just because they do not stock it does not mean they can not get it.