Some questions concerning spooge

[Doc Brown]

I run my EC300/19 50:1 with Putoline MX9, which has a very low pour point and should produce less spooge than e.g. Motul 800 with an extremely high pour point.
But it in fact it produces quite a lot of spooge and so do my buddies bikes, three GP300's and my GP300/18.

All bikes are jetted slightly different, mine run on a JD red needle, Martin's is totallly stock and runs very nice and the two others use the NECW needle but different main jets. All bikes get 50:1 premix. And they all spooge.

On the GP300 with JD-red I reduced from 50:1 to 60:1 and finally to 80:1 to get rid of the spooge. After talking to James (Dean) and also a kTM technician who said KTM's TPI's run 30:1 at WOT but as low as 100:1 at very low throttle opnenings, I went back to 50:1 just to be on the safe side.

I had two 300 EXC's and both Katos survived far over 150 hrs with 80:1 using Amsoil Saber. The GP300 killed 7 spark plugs in less than 10 hours and was immediately cured by just using a different oil.

In a nutshell: how can I reduce the spooge? My bike is already jetted on the leaner side as I dont go WOT in high gears for more than just 7 seconds. I tried different oils (Putoline MX9, Motul 710, Motorex Crossp. 2T, Silkolene/Fuchs 100S, Castrol Power1) but there was no big difference.

Thx for any advice!

 

[ECRider]

I have a 2018 GP300 and running a TSP cut head and NECH needle 38PJ 175MJ #8slide. The head work with squish reduced to 1.35mm helped to reduce the spooge which used to dribble on to the brake caliper at 50:1 Castro tts synthetic oil. I now run 55:1and spooge has reduced to a minor dribble at the muffler after a days ride. I ride a mixture of fast and technical trails

 

[Doc Brown]

Many thanks, appreciate your help.

I had a slight fear that this might be a possible answer. Me too considered that it could be a problem with the head design, the squish seems to be very big for a strong twostroke. I have no clue why GG made it this big, maybe to just be able to accept bigger deviations from the desired value during production...

Did I say that my bike runs really nice? So nor problem here, its just a little flaw. But I always try to get things perfect

 

[ECRider]

TSP actually reduced the compression ratio after maching to reduce the squish but couldn't take it down as low as they wanted to due to insufficient material thickness in the head.
The bike use to have a real kick coming into the mid range & signed off early. The power now is smoother & strong throughout with longer rev range.

 

[Doc Brown]

Sounds good to me. Many thanks for sharing your experiences.

 

[Cox76y]

DOC,
i too am having the same problem with my 18 300 six days. Jetting seems fine n Im hesitant to go any leaner. I had a 2012 with a HOH exhaust n pipe n JD jetting kit. Squish was adjusted by TSP in Australia. In 5 yrs riding I never had a foul plug n cant ever recall having any spooge at all.
So far on my 18 I have gone through 5 plugs in less than 500kms of riding. Im hoping to get the squish set soon and I hope that will help reduce the problem. The only other thing I though of was that the vent hoses from the powervalve and cylinder were blocked and the crap from them was working its way back into the combustion chamber. Not sure if this is the case though n not sure if the GP model has them.
At the moment though I have to always take a spare plug with me on a ride cause there is a good chance I will be needing to swap it over. Never had to do this before.
Anyway, hope someone can work it out.
Josh

 

[Doc Brown]

DOC,
i too am having the same problem with my 18 300 six days. Jetting seems fine n Im hesitant to go any leaner. I had a 2012 with a HOH exhaust n pipe n JD jetting kit. Squish was adjusted by TSP in Australia. In 5 yrs riding I never had a foul plug n cant ever recall having any spooge at all.
So far on my 18 I have gone through 5 plugs in less than 500kms of riding. Im hoping to get the squish set soon and I hope that will help reduce the problem. The only other thing I though of was that the vent hoses from the powervalve and cylinder were blocked and the crap from them was working its way back into the combustion chamber. Not sure if this is the case though n not sure if the GP model has them.
At the moment though I have to always take a spare plug with me on a ride cause there is a good chance I will be needing to swap it over. Never had to do this before.
Anyway, hope someone can work it out.
Josh

Hi Josh,

thanks for answering. I can live with the spooge problem, its just something which annoys me a bit. As the bike is running close to perfect I will not change the jetting.

Concerning the gear and crank case vent hoses I found them connected to the air intake boot on the GP 300 aswell as on the EC 300. I disconnected them and took the nipple out, then put a screw in with Loctite so that no air can be sucked in.

Plug fouling. My GP 300/18 fouled 7 plugs in less than 10 hours and I was really stumped. I changed the ignition coil, ignition cable and cap, CDI and even interchanged the carb. Nothing helped. I also tried NGK Platinum plugs(BR8EIX).
Then after weeks of trying and reading on the internet I found a statement from an US guy who, in a nutshell, said its ALWAYS the jetting and NEVER anything else. People told me this guy is a guru.
Today I can say he knows fuck all about it. I changed jetting to the far lean side, even reduced the premix to 80:1 and the bike still fouled plugs. I then checked the ignition system and pick up aswell as the alternator output, charging current etc.

In my desperation I talked to James Dean and he asked me which gas and oil I use. 102 octane premium pump gas and Amsoil Saber Pro mixed 50, 60, 70 and 80: 1 was my answer.

Following James' advice I drained the tank, filled standard 95 octane pump gas and mixed 50:1 with Castrol Cross Power 2T. With two spark plugs in my backpack I started but the plug survived about 20 miles. I was puzzled but even on the next day it run normal but too lean. After re-jetting back to a richer configuration I gave it another try and did 50 miles but all was normal. As the bike killed the first plug after I washed it I jetwashed it with engine running, then killed the engine and drowned it with water. Started it and let it idle for 10 minutes, as it killed the second plug while it was idling. But all was good.
The bike then has done 40 hours and never again fouled a plug. Till today I can't believe that gas or oil could have been the reason but that the bike is running proves me wrong. Friends suggested to fill 102 octane again and use Amsoil saber Pro to see if the plug will die again but as you can imagine I just didnt want to try that.

What oil are you running and which gas? It was an easy fix for me, maybe it could be one for you too. I used the gas from a 60 liter barrel and Amsoil said dont use the Saber Pro in your bike. Even after informing them that Slaven's uses it they insisted to not use it.

I used the same brand and type of gas plus the Amsoil saber oil in both my KTM's, together over 250 hours and I had no problems.

Give it a try, use dirfferent gas from a different brand and mix it with fresh oil from a different brand. It wont cost you a fortune and if it doesnt help you can at least say its not the gas/oil.

Please let me know how things go on.

Cheers
Doc


PS one thing I cannot totally rule out that I have mistakenly filled the oil twice into my 60 liter barrel. But as I run 80:1 at that time in all my bikes even double the oil would have reduced the mixture to 40:1 ...

 

[Neil E.]

I've used the same plug for four years. When it got a bit grungy, I put in the plug I had been using for the previous two years. I'm using Motul 800 at 40:1 and I get spooge, but it doesn't concern me. I added a custom exhaust tip that creates a drip point so nothing ever runs down the muffler. I repack my Q-stealth every year.

Correct jetting will reduce spooge a lot, however the only way to get rid of it is to find a low flashpoint oil that works right. The idea is that the oil will be completely consumed with combustion. Note that a spark arrested muffler will be a source of spooge just from the action of the arrestor. The swirl bullet type tends to fling oil vapour of out the exhaust. Even a screen type will condense some oil.

 

[taylor146]

TSP actually reduced the compression ratio after maching to reduce the squish but couldn't take it down as low as they wanted to due to insufficient material thickness in the head.
The bike use to have a real kick coming into the mid range & signed off early. The power now is smoother & strong throughout with longer rev range.

Hi ECRIDER
Do you know what the comp was to start with and what they reduced it too?

thanks

 

[Jakobi]

I've used the same plug for four years. When it got a bit grungy, I put in the plug I had been using for the previous two years. I'm using Motul 800 at 40:1 and I get spooge, but it doesn't concern me. I added a custom exhaust tip that creates a drip point so nothing ever runs down the muffler. I repack my Q-stealth every year.

Correct jetting will reduce spooge a lot, however the only way to get rid of it is to find a low flashpoint oil that works right. The idea is that the oil will be completely consumed with combustion. Note that a spark arrested muffler will be a source of spooge just from the action of the arrestor. The swirl bullet type tends to fling oil vapour of out the exhaust. Even a screen type will condense some oil.

Money on the head.

I've never fouled a plug on either of my previous 2 engines in combined 500+hrs of riding. I used to change plugs when tuning, and maybe with a top end as part of its birthday present.. But never had one fail. I hope my 2018 follows suit.

 

[Jetster220]

I fouled one plug on my '18 in the 85 hours I've ridden it, an that was when I was still getting the jetting right and it was running to rich. Now it's perfect, no spooge and plug looks just right, running 93 pump and amsoil dominator at 44:1.

 

[Cox76y]

Ive just been grabbing whatever the local shop has. Last pickup was the Motul 800. Hadnt googled it until you suggested that my oil could be part of the problem. Looks like a lot of people have had spooge n smoke problems with it. I have tried other oils but now, come to think of it the plugs are gunking up much quicker with this stuff. I might jump online and see if I can get some amsoil n Ill give it a try. Might solve part of the problem I was having with the smartcarb as well.. Think Ill still check the squish as well. Fingers crossed..
thanks everyone for the info.

 

[ECRider]

Hi ECRIDER
Do you know what the comp was to start with and what they reduced it too?

thanks

Before head work compression was 155psi and afterwards 150 psi

 

[memphis2857]

Before head work compression was 155psi and afterwards 150 psi

That’s awfully low. Should be around 200.


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[Jakobi]

That?s awfully low. Should be around 200.

Yes no yes. The number alone means sweet FA. Some 'quality' gauges use adapter fittings.. they can add a couple of cc's to the trapped volume which will in turn give a lower reading than the engine actually is. Even more so if the volume of the tubing is counted.

Comp readings mean verrry little unless a specific gauge is used to make comparisons.

My cheapo gauge always reads low, but my engines run strong and happy. I just work off percentages of compression loss along with piston blow by, coating wear, etc visible when peaking in the exhaust port... to help determine when a top end is due. Typically around 70hrs for me.

 

[ECRider]

I wouldn't be surprised if I lost 5 psi or so with my gauge as its a rubber cone push on type you have to jam on when doing the reading (ie not screw fitting).

Before I had the head done I tried reducing base gasket thickness to 0.15mm (0.5mm stock) & this raised the compression to about 160 psi & reduced squish to 1.35mm.

This made it a bit harder to kick, improved jetting & spooge, but power delivery was not what you call smooth with a big kick coming into the mid range. Fun but not fast (for me).