Jetting recommendation

[Clean02]

I recently picked up a 98 (I think) blaster as a project. New to the blaster and to quads. The bike ran but had low compression, so the head is at the shop getting re done.

The bike will have a wiesco piston. It looks like it has an aftermarket head pipe because it is polished. I'm not sure if the silencer is aftermarket because I can't find a brand on it.. I have a new UNI Foam filter and no airbox (because I didn't get one with the bike). Oil injection has been deleted and will be running 32:1 mix. I'm only about 100ft above sea level. The bike has a stock jet and was running with no airbox and the aftermarket head pipe and injection pump delete, which is my guess why the top end was shot without re jetting... So I'm looking for a starting point for jetting and needle setting, I was planning to buy maybe jet sizes 260 270 280 290 300. But if I could narrow it down it would be nice. All help is appreciated.

 

[Wifesblaster]

Order 270, 280, 290, and 300 mains. Put the clip in the middle slot of the needle. stock pilot, and 1.5 turns out on the air screw. Put the 300 in for break in. After the motor has been broken in (1 tank of fuel) plug chop it. Do not rip through all gears when breaking it in.

 

[Larry's Shee]

There is no stamp or tag on pipe? Stock silencer is about 3 1/2" dia and would have Yamaha stamped in it, A.M. silencers are much smaller.
What will be avg. riding temps?
Are these ALL of your engine mods? (that you know of?)

 

[Clean02]

Order 270, 280, 290, and 300 mains. Put the clip in the middle slot of the needle. stock pilot, and 1.5 turns out on the air screw. Put the 300 in for break in. After the motor has been broken in (1 tank of fuel) plug chop it. Do not rip through all gears when breaking it in.

Thanks for the reply. Will do. I ordered a carb rebuild kit also.

 

[Clean02]

There is no stamp or tag on pipe? Stock silencer is about 3 1/2" dia and would have Yamaha stamped in it, A.M. silencers are much smaller.
What will be avg. riding temps?
Are these ALL of your engine mods? (that you know of?)

As far as I know those are all the mods. I will post a picture of the pipe. Average temp in ny is freezing right now. 20-30s

 

[Clean02]

Here's the pipes I got it with. I cleaned up the head pipe. It was pretty rusty and dirty. The silencer I didn't clean. Looks a bit beat up.

 

[Wifesblaster]

Judging by the flange and silencer it looks to be an LRD exhaust. Good pipe IMO

 

[Clean02]

Judging by the flange and silencer it looks to be an LRD exhaust. Good pipe IMO

Oh ok, Thanks for that info. So I guess it's a full exhaust that I will be running.

 

[Blaaster]

As Wifes says put in the #300, do heat cycles, re tension the head and jug and run 2 tanks of gas at no more than 3/4 throttle, that will keep it off the main until it is time to plug chop.

When using a forged piston in very cold conditions, please warm it up well before fanging it or you may cold sieze the piston.

 

[Clean02]

As Wifes says put in the #300, do heat cycles, re tension the head and jug and run 2 tanks of gas at no more than 3/4 throttle, that will keep it off the main until it is time to plug chop.

When using a forged piston in very cold conditions, please warm it up well before fanging it or you may cold sieze the piston.

Awesome. Thanks for the help and info. Looking forward to getting it up and running for some of the last snowfall here.

Is there any tips I should know for re installing the top end, gaskets or the carb? I plan to do some more researching on here before I button everything back up...I also have to find a rubber cap to block the oil injection inlet on the carb which was also left open when I got it.

 

[Blaaster]

Only use OEM or Cometic gaskets, in no way use the blue/green paper base gaskets, they leak.

Tension the nuts to specs, perform heat cycles and observe break in procedures.

Use the correct procedure when tensioning the reed cage bolts.

Pot some sealant in the cap you block the injection nipple off with.

 

[Clean02]

Only use OEM or Cometic gaskets, in no way use the blue/green paper base gaskets, they leak.

Tension the nuts to specs, perform heat cycles and observe break in procedures.

Use the correct procedure when tensioning the reed cage bolts.

Pot some sealant in the cap you block the injection nipple off with.

Thanks. I planned to use oem gaskets for the jug and top. And I will look up torque specs.
What about the gaskets for the reed, carb etc.. I ordered a few "Vito's" reed gaskets off eBay. And I got a carb rebuild kit off of eBay and was going to use the bowl gasket.. Are those ok to use or are they junk?

 

[Blaaster]

It is really only the blue/green jug gaskets that cause problems, I have not had any problems with reed and bowl gaskets.

Torque for head is 20ft lbs, jug eighteen ft lbs and reed cage five point eight ft lbs.

You would not believe it my numerics died during this post.