Snowmobile Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1
Hello, I am having some problems with my 1999 zrt 800. I recently changed the pipes and installed a clutch kit, I am wondering if the jetting needs to be changed. The sled seems to bog when the revs increase (sled gets gas, has spark and lots of air). I also installed some clamp on air filters (UNI), and deleted the oil reservoir.

Installations:
-D&D pipes installed (stock resonator).
-Secondary helix changed (57/50 --> 60/40).
-Secondary spring changed (yellow --> red).
-Primary weights changed (539-53 --> 10-58).
-Primary spring changed (red --> orange).

Note:
-I believe I'm running 400 main gets and 35 pilots jets.

Hoping someone who knows more about this than me can help, I appreciate your time!

Thanks,

Wyatt
 

·
Super Moderator
Joined
·
1,812 Posts
Welcome
I race that sled!
Go back to the air Box and increase your mains and do some runs and check your plugs!
Why did you loose the injection system?
 

·
Registered
Joined
·
4 Posts
Discussion Starter #3
Thanks for the reply!

I had to remove the air box because there was not enough room for an appropriate fuel filter to fit in behind it. There were also rips in the flange that fit to the carbs. Consequently I added the clamp on air filters which rubbed on the oil reservoir and the jack shaft. I made a flange to shield the jack shaft and removed the oil reservoir. From there my air filters fit. I capped the oil line going into the fuel pump and returned the oil line coming out of the oil pump to the oil line going in to the oil pump. I run it at 50:1. I also mounted the CDI pack to the steering column rack.

Any idea if the CDI needs to be insulated from the frame? Would there be less of an air flow with the clamp on filters? Any idea of what size of jets to go to? Maybe all this work was for nothing.

Again I really appreciate the help!
 

·
Registered
Joined
·
1,008 Posts
Can tell you right now he is going to tell you to ditch those clamp on filters and he is right to do so. All you are doing is sucking in warm air into the engine which is no good for making power. Find a replacement airbox or flanges and put it back on. Find a fuel filter that will fit properly otherwise you are just causing yourself more headaches in the long run with those clamp on air filters.
 

·
Super Moderator
Joined
·
1,812 Posts
I cant find my pics of my ZRT, but what you are doing IS going the wrong way!
Those pods are your problem!
If you are looking for more HP there is over 200hp waiting to be tapped!
 

·
Super Moderator
Joined
·
1,812 Posts
I took a National with it at St Germain back in 2013 1000' ice 119mph!
Backed it up in 15 on the Asphalt 1/4 mile, same gearing and even the same jetting10.4 128mph I am at bout 205hp
 

·
Registered
Joined
·
4 Posts
Discussion Starter #7
Yes I am definitely looking for more HP, if i could eventually get to where you are that would be great! Are you running the 800 jugs, or is yours bored?
 

·
Super Moderator
Joined
·
1,812 Posts
Air flow too restrictive Snowmobile do NOT have an air filter!

What I did was I used a SLP air box and the open top became a Plenum and I ducted the hood to it!

The OEM air box can do the same just remove the tool box.
But you wont need to go to that extreme
Get a complete gasket set
Pull the reeds and look in, you will see the bottom of the jugs skirt, scribe it!
Pull it apart, set your base gasket on the upside down jug as well as the cases.
Now you see were they left all the extra HP!
Match port and flow the cases too!
Then turn .030-40 off the heads
As for the exhaust do basically the same but you don't have to remove near as much,
just get it to flow!
Im running CPR pipes D&D are just as good!
I am running a set of Rack carbs bore to 41mm and Vforce3 reeds
 
1 - 9 of 9 Posts
Top