Sadly I need a little jetting help here

[99LRDblaster]

I got the Blaster out today and started it up with:

33.0 pilot
290 main
and the Vito's needle is I believe in the 4th position....haven't checked in a while.

Well I went out to start it and it started right up and it idled VERY high. Not revving to the moon, but it consistently stayed at a high idle. Air screw adjustments had absolutely no affect on it. Now I just did a leakdown test and the engine is air tight. It held 7psi for well over 15min and didn't even budge.

So I took the carb off and had some smoke rolling out of the engine and it just kind of smelled a little hot. So not chancing it I just threw in:

320 main
left the needle at 4th spot
but changed out the 33.0 for the stock 32.5 pilot....just out of curiosity.

Started it up and it idled a lot lower and appropriately. Went out for a ride and the main performance was worse, but it still ran ok.....it didn't flood out like I thought it would. I have some videos of it that I might post if it brings any aid.

I'm going to take it outside city limits with new plugs obviously to get it "dialed" in, but just taking for a casual stroll through the yard, what's the deal with the idle and revs hanging? Could it be a carb boot leak? I would think if the 33 pilot was too rich it would just flood it out as opposed to idling high(unless extra air was coming through). Reed issue? :-/

 

[Awk08]

i believe at idle, a stock pilot is more than enuf for the stock carb, no matter what other mods, that little 26mm can only flow that much air at idle,
i also believe the middle clip position is sufficient, and with that porting and pipe, 290 was way low, 320 sounds close, but i'd try bigger and see what happens, and plug chop as you already know

 

[sicivicdude]

Well his carburetor isn't a 26mm anymore but I agree with you awk, most of the time the stock pilot is enough.

The "smoke" you saw is totally normal for high volitility fuel, it's the vapor that's left after the fuel is atomized.

I would think that the jetting is certainly in the ball park for your mods. I'm thinking you either have a hanging slide (because of it being bored so large) or a hanging throttle cable.

 

[99LRDblaster]

I'll look into those.

This vid is just the first time I got it out with the 33.0 pilot and 290 main.......and yes I realize it's boggy as hell right now....I'll take care of that once I get it out in the country. I'll see if I can get the other vid up. The idle was so high I didn't even need to use the throttle to get it into gear...good thing because I didn't have 3 hands to operate the camera, throttle, and clutch all at the same time. It takes like 4 hours to upload a short vid on youtube with my connection. There is a lot of BS in this vid so you can fast forward through a lot of it. I'm going to check into the carb boot clamp. I'm not sure if it's tight enough......even clamped all the way down.

 

[NEONNIGHT34609]

have you tested for air leaks ? mine was doing same thing and the crank seal was leaking like hell

 

[99LRDblaster]

have you tested for air leaks ? mine was doing same thing and the crank seal was leaking like hell

Yep......it's tight as tight can be.

Yea I know.......that's what she said.

It held 7 psi for 15 min and it didn't even budge. I feel confident it would of held it for an hour if I let it. I'll post the other vid once it uploads........which is FOREVER. It SEEMS to idle fine then with the 32.5 pilot. Jetting has just been a pain in the ass since I have had to compensate for so many extraneous factors....the biggest being the high octane mixed gas now, since it's TRUE power can actually be utilized now. It runs COMPLETELY different and the jetting is now completely different. Hopefully, I can get it out in the fields this weekend to jet it.

 

[99LRDblaster]

Here is the other vid after I put the 32.5 pilot in and the 320 main in. You can see without even messing with the air screw, it idles much lower. Not much to see as it's mostly just me dicking off in the yard for a couple minutes.

 

[Surfrjag]

are you running oxygen enriched fuel? if not i dont see how any higher octane would give you more power in fact the opposite. that is unless your running high compression and or advanced timming. If your idle is changing so much it sounds like a air leak somewhere but seems to be running good in the vid though and a nice looking bike!!

 

[99LRDblaster]

are you running oxygen enriched fuel? if not i dont see how any higher octane would give you more power in fact the opposite. that is unless your running high compression and or advanced timming. If your idle is changing so much it sounds like a air leak somewhere but seems to be running good in the vid though and a nice looking bike!!

Nope....just regular 65/35 mix of Sunoco/Cam2 110 and 93 octane. I'm running higher octane because I had pre-deflagration on straight 93 octane running at 175-180psi compression. I'm going to advance the timing here in the next month or so as well. Meh....it's running fairly crappy right now(better than before though). If you watch the first vid, it bogs pretty heavily with the new fuel mix, which is odd, so I'm going to have to go out and play with the needle to get that cleared up.

No air leaks. Held 7 psi for 15 minutes and never budged. When I reassembled the top end, every gasket received an aided coating. Head gasket got copper sprayed, yamabond on all gaskets and the the reed cage/intake is absolutely LAYERED in yamabond. I could of put the top end on without gaskets even and it wouldn't leak from there. I'm sure it will be a biotch to get off though if I go to a 33PWK and have to take the intake off though.

 

[Surfrjag]

that compression constitutes higher octane anyway... be carefull with timming advance with that compression i would suggest using full cam2 fuel if you do. I would also suggest removing that vitos needle and try with the stocker cuz I have herd of people having problems with that needle but if you get it cleared up then run it!

 

[99LRDblaster]

that compression constitutes higher octane anyway... be carefull with timming advance with that compression i would suggest using full cam2 fuel if you do. I would also suggest removing that vitos needle and try with the stocker cuz I have herd of people having problems with that needle but if you get it cleared up then run it!

Yea, I'm going to watch the timing advance when I do it. The higher octane helps in a different way from compression in that case simply because a higher octane fuel deflagrates slower and has a slower flame front off the head to come back to hit the piston. I was wondering about the vito's needle as well. I don't know where the hell the stock needle went to, so I'll just have to work with it. I haven't even played with the needle yet after putting the needle in, so it's probably fine...just needs adjusted.

 

[Surfrjag]

i would try raising the clip (lowering needle) 2 positions and leave that main in and see if that helps

 

[99LRDblaster]

i would try raising the clip (lowering needle) 2 positions and leave that main in and see if that helps

Yea, I'm going to go out here in a bit and raise it back up to the third position(I think it's in the 4th...can't tell....it's been YEARS ) and then I'll put my 330 main in. The 330 is the largest I have right now......probably too rich until I can get it out to "freedom" and jet it, but I can live with that compared to running lean.

 

[99LRDblaster]

I raised the clip up to the 3rd position and started it up(didn't ride) and it sounds weird and still doesn't seem to rev consistently. Of course I started it up and it would just BWAAA and bog out and almost die, so I just shut it off. I go out about an hour later and start it and it runs decently fine. Temperamental SOB. Just have to see once it gets out in the country I guess.....not much else I can go off of.

 

[YFS101]

back your idle screw out.... not the mixture screw, or adjust the free play in the cable

its not an air leak otherwise the idle would hang for a while then drop down. its not to rich because its not mis firing, its not to lean because its not hanging.

I would do the stock pilot and 290 main with the vitos needle

 

[99LRDblaster]

Just as a bit of an update. I took a few plug chops the other day and wanted to get a 2nd opinion on them for those more experienced with the ACTUAL chops than myself.

What do you guys use for the actual chops? I used a dremel and bench grinder, but I figured there were easier ways like maybe a pipe cutter?

Old plug on left.....lasted me a long time...can't take anything from it as it's been through about 8 different jetting setups.

2nd plug is Vito's needle/3rd clip at 1/2 throttle. 3rd plug is WOT on 320 main. 4th plug is WOT on 330 main.

This guy's been through hell and back but still works fine even 6 years later.

Vitos needle/3rd clip 1/2 throttle

WOT 320 main

WOT 330 main

And a few comparison pics.
1st-Vitos needle/3rd clip 1/2 throttle run, 2nd-WOT 320 main, 3rd-WOT 330 main

-My thoughts are the main is rich on the 320 and 330. I kind of figured that, but played it safe by running them anyways. It ran faster with the 290 main in it. Unfortunately, I don't have a 300 or 310 so hopefully 290 doesn't run it lean when I do the next plug chop.
-The needle is intriguing. The Vito's needle has a steeper taper(richer needle), so I kind of get the feeling I might be fine going up on the needle to the 2nd clip(from top). The plug chop is kind of odd as it has a wider area on the insulator and threw some oily residue along the base of the insulator.

What do you guys think?

 

[slickerthanyou]

I would be happy with the 320 or the 330. I like it a bit rich. but i think you could go down to 310-300. All those last pics look great to me!

 

[99LRDblaster]

I would be happy with the 320 or the 330. I like it a bit rich. but i think you could go down to 310-300. All those last pics look great to me!

I typically run the main 1 size richer than the "perfect" main.

The 320 and 330 main seems way to rich. I mean it runs fine and everything from 3/4 to Full but ran faster on 290. Then again I haven't done a plug chop in half a decade so I'm not as sharp on taking readings off the base of the insulator as I probably once was.

The biggest problem I am having is the odd idle and idle up to the needle opening. It seems to studder like it's rich while riding, but bogs and shuts out almost like it's lean while sitting still. 8-| I've jetted a lot of other bikes and quads and none have given me the headache this little Blaster has. I'm not sure if the taper of the needle is causing an immediate flooding effect around 1/4 throttle while the needle is sliding upward or what, but I'll have to play with it and figure it out. Being too rich on the main probably just exacerbates the problem when the needle moves.

 

[slickerthanyou]

I typically run the main 1 size richer than the "perfect" main.



The biggest problem I am having is the odd idle and idle up to the needle opening. It seems to studder like it's rich while riding, but bogs and shuts out almost like it's lean while sitting still.

It sounds like the pilot needs to be dialed in before ya do anything else. If you have to go more than 2 turns out (from all the way in) on the air screw to get the fastest idle then you need to drop a size on the pilot, If you have to go opposite then step up one and try, This step stumped me for the longest time. Dial in your pilot first, then dial in your main( plug chop), then play with the needle. Cause your 1/2 to WOT chop looks perfect to me.

 

[99LRDblaster]

It sounds like the pilot needs to be dialed in before ya do anything else. If you have to go more than 2 turns out (from all the way in) on the air screw to get the fastest idle then you need to drop a size on the pilot, If you have to go opposite then step up one and try, This step stumped me for the longest time. Dial in your pilot first, then dial in your main( plug chop), then play with the needle. Cause your 1/2 to WOT chop looks perfect to me.

Tried the stock 32.5 and 33.0 on all mixture screw settings. Still bogs when you "floor it".....hesitates then takes off. If you watch the 1st vid in this thread when I'm riding around the yard, you can see what I mean when it goes through the BWAAAA bogging session(sounds like beating on hollow drums) then hits the powerband and main jet and takes off.