Spark Plugs

[kusmaker]

Re: Help me read my spark plug!

Is it possible to use bosch twin electrode spark plug in yamaha rx100, are there any mods required, using of spitfire cable or msd cables necessary with twin electrode to get better results.

[AK3D]

Re: Help me read my spark plug!

Well I have a modified R15, have just done some more mods and have tweaked my ecu fuel map. Now I got the bike back a couple of weeks ago, I have been running a CR9E(IX) plug for a couple of years on the old set up as recommended by Joel, these used to foul up every 1500 km's or so, now with the new set up I think my compression is reduced, the same colder plug would foul within 30-50 km's (although I have tweaked my ecu map at least 8 times in between) , so I changed the spark plug to a hotter one (stock rating, I think) stock is CR8E, I have a champion plug made for Bajaj 220 marked RG6HCC, the 6 is the heat rating which according to my research is the equivalent of NGK CR8E, the CC means double copper or something like that. The fuel map I have tweaked by feel, to give me a good base map, I intend to do a wideband AFR tune up soon, however I am sure with the old map the plug was fully black yesterday morning, I put the new map on yesterday and went for a 13 km ride each way (total 26km), this is the reading after that ride.

Now according to my eye/brain co-ordination, my reading is between 12 & 13 on the attached chart, which means I am close to where I need to be, however I don't trust my judgement, now can anyone give me an educated second/third or fourth etc.....opinion on the reading?

Thanks for the tag [MENTION=41586]Divya Sharan[/MENTION]
The plug looks good, very slightly lean. However, please rub a finger around the spark plug electrode, if there are traces of oil, it means something else is wrong. I cannot make that out from the pic, and the black edges do look shiny - as in oil deposits.
If, as you say, the plug was fouling earlier, it would not just be due to a simple remap.

[stefanm]

Re: Help me read my spark plug!

Thanks for the tag @Divya Sharan
The plug looks good, very slightly lean. However, please rub a finger around the spark plug electrode, if there are traces of oil, it means something else is wrong. I cannot make that out from the pic, and the black edges do look shiny - as in oil deposits.
If, as you say, the plug was fouling earlier, it would not just be due to a simple remap.

It's petrol over carbon deposits, it cleaned up easily with 240# sand paper, I have a feeling that was from the earlier map, there is a slight flat spot within the self cleaning range, I will try to iron that out before riding. I don't feel I need to go for a colder plug again (shame, I got a new Iridium CR9EIX with me), will probably take a ride later, if it stays dry I'll pull the plug again.

[AK3D]

Re: Help me read my spark plug!

It's petrol over carbon deposits, it cleaned up easily with 240# sand paper, I have a feeling that was from the earlier map, there is a slight flat spot within the self cleaning range, I will try to iron that out before riding. I don't feel I need to go for a colder plug again (shame, I got a new Iridium CR9EIX with me), will probably take a ride later, if it stays dry I'll pull the plug again.

Petrol evaporates, oil will stick. If you need to clean up the deposit with sand paper, something else is wrong. Again, did you put your finger (or a piece of paper) around the plug once it was cooled and see whether the deposits stuck?
Self cleaning range? I did not understand that.

[stefanm]

Re: Help me read my spark plug!

Petrol evaporates, oil will stick. If you need to clean up the deposit with sand paper, something else is wrong. Again, did you put your finger (or a piece of paper) around the plug once it was cooled and see whether the deposits stuck?
Self cleaning range? I did not understand that.

The photos were taken directly after I removed the plug, it was dark outside hence I took photo's to get a closer look, the plug had petrol on it, the shiny effect was accentuated by the camera flash and halogen lighting in my kitchen. Most the deposits wiped off with a tissue and were dry to the touch, I just gave a light rub over with sand paper to remove the carbon which was probably from the earlier map(s).
Now the thing is I tend to make mostly short journeys and when the engine is cold it will run rich, initially the Fast Idle Solenoid increases idle speed and reduces air intake, similar to a choke on a carburetor, also the ecu maps have enrichment features depending on coolant temp, lower coolant temp = more fuel, now this all begins to foul the plug, now when you are up to operating temp and riding at high rpm's the plugs begin to self clean and the carbon deposits burn off, with stock engines issues with spark plugs are usually mean a problem, such as clogged air filter, fuel filter, exhaust leak, blocked injector, poor timing, carb problem etc. With a modded engine, these you want to run a little rich, you target around 12.8:1 AFR compared to 14.7:1 Stoich which is pretty much what stock motors are trying to achieve. So you can see without prolonged high speed use, plug fouling will happen, now with it being so freaking hot right now, I don't much feel like riding too much, it gets pretty hot with the full riding costume on.

Now with my reading I am trying to figure which one it's close to on the chart, according to my eyes it's pretty close to no.12, which if correct I am close to where I need to be, which will give me a good base map to work from once we hook up a wideband O2 sensor and data logger. Though I still can't 100% verify the reading with the chart.

[Trd2000]

Re: Spark Plugs

That looks to me like you're running too hot. Possibly because its lean? Running lean might make you feel like you've tuned the bike well and it's makin good power, but it will raise temperatures and potentially damage the engine. Bearing in mind ou changed plug heat range... I'd try putting some more fuel in, then see if it fixes it.


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[stefanm]

Re: Spark Plugs

That looks to me like you're running too hot. Possibly because its lean? Running lean might make you feel like you've tuned the bike well and it's makin good power, but it will raise temperatures and potentially damage the engine. Bearing in mind ou changed plug heat range... I'd try putting some more fuel in, then see if it fixes it.


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Hmmm, interesting. I'm using stock heat range, I seem to have an air leak somewhere on the inlet, I can't get the idle down to normal, this all happened after I changed plugs last week, one minute fine, then after some WOT riding, the idle is high, now it's stuck on 2-2.5k rpm with the idle screw turned to minimum. With a colder plug i'm getting a lot of fouling within 20-30 km's, although the fuel map has been tweaked after I switched plugs, need to do the wideband tuning asap, will need to do 10-15 runs with the data logger.

[Trd2000]

Re: Spark Plugs

Why did you change the map? If you still have the old map, try reloading it, run it with the new plugs, and see how it goes. I'd try that before anything else...... I really wonder if you're running way too lean. The cold start enrich might be covering it up till its warm


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[SparKot]

Re: Spark Plugs

I was looking up for G-Power substitute of CPR7HSA for my GS150R, only there weren't any.


I found equivalents for Hero-Karizma.

DPR8EA-9 => DPR8EGP => DPR8EIX

Even for Suzuki-Access & Honda-Dio(102cc)

CR6HSA => CR6HIX => CR6HIX
.

'P' in CPR7HSA => Projected center electrode insulator

What's the purpose of Projected center electrode insulator?

[Trd2000]

Re: Spark Plugs

Probably just better positioning of the spark in the combustion chamber.... But I'm not sure.

[SparKot]

Re: Spark Plugs

Probably just better positioning of the spark in the combustion chamber.... But I'm not sure.

Yeah shoeb2015 explained it well here:

http://www.xbhp.com/talkies/motorcycle-ownership-experiences/6831-suzuki-gs150r-475.html#post1065756

[curve_king]

Re: Spark Plugs

Anybody know about a NGK spark plug dealer in Pune ?!
Even bosch/mico or champion dealer will do, as long as an equivalent to CPR8EA is available with them.

[SparKot]

Re: Spark Plugs

Anybody know about a NGK spark plug dealer in Pune ?!
Even bosch/mico or champion dealer will do, as long as an equivalent to CPR8EA is available with them.

check this address for NGK:
Bijal Agencies
Contact: Mr. Mahesh Shah
Tel: 020-32912820
Mobile: 09272227488
E-Mail: [email protected]
Address: Wagheshwar Complex, Near Wagheshwar Temple, Pune 412207

Source : NGK

[curve_king]

Re: Spark Plugs

check this address for NGK:
Bijal Agencies
Contact: Mr. Mahesh Shah
Tel: 020-32912820
Mobile: 09272227488
E-Mail: [email protected]
Address: Wagheshwar Complex, Near Wagheshwar Temple, Pune 412207

Source : NGK

Now that was quick.
Thanks n does bosch/mico or champion have a sort of product catalogue where we can check which ones have got a projected nose n therefore find a suitable equivalent to CPR8EA.

[SparKot]

Re: Spark Plugs

Now that was quick.Thanks n does bosch/mico or champion have a sort of product catalogue where we can check which ones have got a projected nose n therefore find a suitable equivalent to CPR8EA.

They should have those conversion charts wherein you can figure out substitutes. It's just that I was looking at NGK site & you got a quick reply.