OK Crawdad, uflg95, Mike Chero and the rest of you big dogs; I need some advice (please).

I have just added a HPD Trail pipe and 39 mm carb. I am considering removing the oil injection. I want to run Amsoil pre-mix (80:1) but I don't know if it affects jetting (and the plug reading). Do you guys know? This is the ratio and oil HPD uses and recommends.

I have searched and saw where uflg95 (in Oct 2001) posted the question in relation to some UFO gizmo, but I just want to pre-mix. So, what if anything will Amsoil do to the plug reading? Should I jet keeping the oil injection on and then remove it or just jet it after removing the oil injection?

If I try jetting with the oil injection removed, then that means I 1) changed the exhaust, 2) changed the carb, 3) modified the air box [per Ritter's trail kit] and 4) removed the oil injection. Is this too much to try jetting or would you guys stage in these changes?

BTW this is all on a 3 week old Scrambler 400.

What is a good starting point of jets on the 39mm? Which pilot, main and needle position should I try for 1400ft above sea level in the winter? Is the pilot that came with the carb OK to use?

Thanks in advance.

Chunky

PS If anyone doesn't know all of the above, I would appreciate discussion on the parts you do have experience with.

 

If at all possible, get a dynojet jet kit, this will give you detailed instructions on how to jet per mod.
The pipe will come with instructions on, well say it's a low end pipe, It will tell you to bump the pilot up one size, or bump the main up one size.
But all in all it will teach you over time how to jet your bike.
I jet many many bikes, and you could line up ten say scramblers and it could be quite possible for me to come up with ten jetting combos, although I doubt it but thier will be atleast a few variations.
Plus it matters were you live the climate and so on!!
As far as two stroke oil, use a type and stick with it, use the amsoil, but stick with it, different mixture oils can and will affect your jetting.
Many will say it won't but a correctly jetted carb it most likely will.
And don't depend on a shop to jet for you, they have a particular jetting set up for certain machines and thets what they go with, they will not sit and try to make your machine correct. In basic terms if you let them do it you will be back asking these same questions within the month.

But first off, let your machine braek in for a while longer before you do all these mods, it will help in the longevity of your motor and dial in alot easier.
Good luck and hope some of this helps!!!

 

Your best reference is going to be Mike or Darrell at HPD. They use Amsoil exclusively there and will square you away. If you bought the carb through them and gave them your relative information as to mods and location it should be jetted close.

Now that you have the 39PWK I would ditch the oil injector. I could be wrong, but with the bigger carb I'm not sure if the injector is designed to be used other types of oil other than Polaris brand, nor will it be able to keep up with the flow of the 39. Besides for $20 it's an easy do it yourself mod that puts you in control of your fuel mix ratio. If the injector ever went out you wouldn't know untill it was too late and repaires would be 5-10X the cost of the block off kit.

Using premix your can also change your mix ratio, IE 80:1, 100:1 or whatever you decide to run, whereas the injector is not adjustable. You will also be loosing about 5-7LBS off the front end (full oil reservoir adn injector components).

I've never used Amsoil so I dont know how it will effect plug readings, but suspect that there shouldnt be much diffence.

I'm not sure what you mean by "If I try jetting with the oil injection removed, then that means I 1) changed the exhaust, 2) changed the carb, 3) modified the air box [per Ritter's trail kit] and 4) removed the oil injection. Is this too much to try jetting or would you guys stage in these changes?" but, I find the 39PWK very user friendly, more so than the 38TMX.

When you say cold weather, what is cold? Here in AZ (approx. 1200-1400' elevatio) I go down from a 175 main in the winter to a 168-172 in the summer, but this is on a full race mod bike.

As for the last post forget about the Dynojet suggestion and after three weeks the bike is broken in. A Dynojet Kit is going to confuse to even more, when all you have to do is call HPD and get a couple of mains and maybe another pilot, for less than $10.

Take it from someone who HAS a 39PWK on their bike, and not someone who has a Lakota with a 13T sprocket!

 

Chunky 5678

The Amsoil you have is for chainsaws and other smaller nonseparate oil mixing machines. There is Amsoil for the more common 50/1 mixing ratios and these oils are almost negative smoke producing mixes. The race oil mix has practically no smoke emitting from the exhaust and Amsoil claims they have not had any 2-strokes cease from their race mixture. I have used this stuff in my chainsaw and weedwacker and I can honestly tell you there this hardly any 2-stroke smell and a considerable amount of power. Amsoil is a good brand and you will be impressed.

 

Howdie fellas,

I just talked w/ Mike from HPD last week on this very subject while I was ordering some things. They (HPD) sell the 100:1 Amsoil, but Mike stated that they mix it 85:1 in their race bikes. I've got everything short of "Race porting" and a "shaved flywheel" on mine. I've been running 927 @ 40:1 for about a year and I fixing to switch to Polaris Premix or some other type of synthetic oil. 927 is overkill and the castor is gumming things up a bit. I'm going to see how some synthetic oil does.

If you got the bigger carb, ditch the injector. It will give you piece of mind and you'll always know that the oil is making it into the cylinder.

Good luck,

EC

 

I would love to get mny hands on Amsoil for my Banshees (2), Sport 400 and Blaster.

Where can I get it in the metro-Phoenix area?

 

Chunky,

I think I'm going to go to Amsoil too this year. The Klotz Supertechniplate I'm using now burns dirty as all heck. Just for general purposes, I'm going to run it at 80:1. From what I understand, it's hard as heck to read an Amsoil plug because it burns so clean. Start off with an oil you trust to give you a good reading (like Bel Ray) and then switch to Amsoil. From what I've heard, It shouldn't require rejetting because of the leaner mixture. As for losing the injector, go for it. I've had nothing but problems when it came to adding a larger carb and trying to keep the injector. Because of the different designs of the carbs, this isn't just a bolt on modification, you'd have to adjust the oil pump too and it's a hassle to say the least.

Hope this helps!

 

If you go with amsoil, you will stay with it.
I've used it in my truck for years and started in my bikes this summer and then to my quad in the fall.
It works graet, it quieted my tranny down completely, and ran much cooler.
We put it in our CR, and very little smoke, and can't smell it.
This stuff works graet, get you some and I promise you will not go back to any other oil.
Send donttreadonme a private message, he'll hook you up.


Now about the lakota with the 13T sprocket thing, If I post my GSXR super comp bike blowing 8.90s all day then does it mean I know some thing, or only if I buy a polaris. Please let me know, you make me feel like I've wasted the last 25 years when all I had to do is buy a polaris.

 

In my mind AMSOIL is the best, thats why I sell it and use it in everything I own. It can be hard to read a plug with it. However if you feel comfortable with your jetting knowledge, go rich initially and the AMSOIL will eventually color the plug after a half day of riding to where you can read it properly. I think you will like the AMSOIL product.

 

uflg95,

One of the reasons I'm going to Amsoil, is because you guys carry it up there. Frankly, I wouldn't even think of going to it, if I didn't have a ready supply. Make sure you stock up for the summer. I have every weekend off in the summer save one (19th-21st of July).