Jetting for 144MC

[capehorn23]

Does anyone have any baseline numbers for jetting on a 144MC? It has the following:
45pj 175mj DG-J #2 needle 2.5as
The bike is running very rich with lots of spooge.
Thanks,
Terry

 

[Elvis74]

I run in Mine
50pj
175 Mathias Hubo
Needle NOZI
Air screw 2,5 out

 

[Elvis74]

By the way, when you have a lot of oil on the exhaust, than the port timing is not adjusted correctly.

 

[memphis2857]

Spooge is not a sign of rich jetting. It is also not really a sign of incorrect port timing. Spooge means that your engine simply can't burn off the lubricating oil (pre-mix oil). This can be caused by using an oil with a high flash point and cylinder temps not being high enough to burn the oil. Remember 2 strokes run pretty cool with exhaust temps sometimes below 300 f. Spooge can also be cause by simply having too much oil. If you are running a full synthetic oil and mixing at 32:1 you will get spooge no matter how lean you jet.

How does the bike run? How does the plug look? Is it reluctant to come on the pipe?
If the bike runs good and you are just getting spooge then you need to look at changing your pre-mix. That being said if you use less oil say something like 40:1 or 50:1 then you will be putting more gas and less oil into the cylinder creating a richer running bike.

 

[Jakobi]

Some silencers contribute to spooge too. I cut down my big Q stealth. It used to spooge and drip everywhere. Same jetting, shortened it, and removed the arrestor and it runs very similar without the excessive oil.

 

[Elvis74]

All of you are right, but changing a 125 into a 144 means you have to bite the cylinder from 54mm to 58mm and this changes the port timing a lot. The most important for this effect is the boost port. Check you timing and check the boost port.
I run my 144 gasser with 1:50 up to 1:60 without any spooge and other problems.

 

[sweeper]

How does the bike run? How does the plug look? Is it reluctant to come on the pipe?
If the bike runs good and you are just getting spooge then you need to look at changing your pre-mix. That being said if you use less oil say something like 40:1 or 50:1 then you will be putting more gas and less oil into the cylinder creating a richer running bike.

Correct but difficult to explain.
If you thought of jetting and cylinder lubrication as entirely separate issues maybe that clears the picture maybe it doesn't.Maybe you can't, but I try too.

As far as maximizing power characteristics to suit your specific needs, cleaning up the bike .That can be a challenge.
In this case another member sounds like he has this specific bike and mod sorted out.Go with that , get the bike performing at its max.,then tweak the rest.Some of the best running bikes are messy.
Keep us posted.