Jetting Gremlin

[Memphis]

Hey 3WW, Kintore recommended I come here to get help with a jetting problem I am having. Long story short, bought a 30mm CPW Race Carb back in the summer (same as Kiehin 30mm). Anywho, back then I had 90lbs of compression. This winter rebuilt the topend on it, all went well, reinstalled everything and the quad was extremely hard to start. Eventually got it started and it ran like a bag of crap (I still have not managed to break it in because I cannot even ride it) So done the odd tinkering here and there adjusting little things but no help at all.

Issues: Starts up after 3-4 Kicks, 120lbs of compression. Idles perfect now that I adjusted it, Bogs @ anything passed 1/4 throttle. Been getting a lot of misreadings from the plug, was a dark brown (or so it seems) when idling.
Struggles to start moving under it's own power
When it was on the 4th clip setting @ 1/2 throttle it was an oil fogger, but the plug was not fouling?

Currently I have not touched the pilot or main jet, but I have played with the needle settings a little (I have no extra jets atm - mine went missing). Off the top of my head I can't remember what the P&M Jets are but previously I was running on the 4th clip setting (from the bottom).

Yesterday I bumped the clip up to the fifth setting (top of the needle) which is supposed to lean up the mixture, I fired the quad up, took it for a run. Still only managed to get it to run @ 1/4 throttle, anything passed that and it would bog, get back home, yank the plug out and the colour did not change at all! the metal contact was gray though.

Currently looking at the "Spark Plug Bible" and neither of my plugs look like the descripted ones (because they have not been run long enough)
http://www.dansmc.com/Spark_Plugs/Spark_Plugs_catalog.html

If anyone can get me some starting figures for Ball Park jetting on a 30mm carb, so I can just restart the whole process that would be GREAT, instead of complicating the current problem.

Thanks 3WW

[Wickedfinger]

You might want to actually tell us what kind of quad or even motor you are running - that would be a good start. .... lol.
The "Oil fogger" comment leads me to believe its a 2-Stroke ...no?
And the smallish 30mm carb sounds like something you might try and fit to a Blaster?.

[slothminx]

I think this is a Shee, an 87 I think ;) ( he says using his mystic powers)

[Wickedfinger]

Yeah, but he said "Carb" as in one.

[slothminx]

and neither of my plugs look like the descripted ones

one carb.... but two plugs!? heh got me confused.

I have only heard of kintores buddys having either an EX or a shee, Since he kick started it I would say its the shee.... But I could be wrong!

[Memphis]

oh man, I have posted this problem on many Blaster forums, I just assumed you all knew what I was talking about sorry hahahaha

Yes, it's a Yamaha Blaster, TORS has been removed, the bike ran decent before the rebuild.

Did some more experimenting tonight
Middle Clip position (3rd)
Idled kind of poopy, had to make some adjustments,
Blipped @ 1/4 throttle and had decent response, if I held it at 1/4 throttle I would get some popping, I managed to get it held @ half throttle and she was a sputtering pos, backed it off to 1/4 and it would come alive again,

Another issue I forgot to mention, cannot start it once warm, I have to turn off the gas and hold it @ 1/4 throttle for it to barely come alive, once I get the revs @ idle and turn the fuel back on, it runs great (on idle and same problems persist).

*Edit*
I am another buddy LOL, but not the one with the shee obviously

Sorry for the miscommunication

[85hondaatc125m]

Jeeze, im not sure, all I can say it replace plugs, clean carb, get a carb kit for it and It should be ready to go and it will only take up like $50. Oh, and I see you are in Ontario and it is probably cold over there so you might want to look for a hotter plug for it. Hope it helps

[Wickedfinger]

Personally, I think your carb is too big for the motor in its present state of tune. Sounds like you are running WAY too rich from your symptoms - especially the throttle past 1/4 issue. You are dumping in more gas than the motor can use and thats choking it out. I would try running it without a filter (temporarily) to see if that'll give it more air to the mix and run better - if it does, you were running to rich - but I think you definitely need to main jet down a few. You probably need to open up the airbox, buy a good aftermarket pipe and get the jug ported, before you will see any real gains from that carb. You plug tests are inconclusive because you havn't really done one yet. They only work off of full throttle chops and you need to get more air in your fuel charge before it will let you do one.

Memphis - Registered User
New to the board Join Date: Oct 2005
Location: Ontario
Posts: 3

oh man, I have posted this problem on many Blaster forums, I just assumed you all knew what I was talking about sorry hahahaha

Yes, it's a Yamaha Blaster, TORS has been removed, the bike ran decent before the rebuild.

Did some more experimenting tonight
Middle Clip position (3rd)
Idled kind of poopy, had to make some adjustments,
Blipped @ 1/4 throttle and had decent response, if I held it at 1/4 throttle I would get some popping, I managed to get it held @ half throttle and she was a sputtering pos, backed it off to 1/4 and it would come alive again,

Another issue I forgot to mention, cannot start it once warm, I have to turn off the gas and hold it @ 1/4 throttle for it to barely come alive, once I get the revs @ idle and turn the fuel back on, it runs great (on idle and same problems persist).

*Edit*
I am another buddy LOL, but not the one with the shee obviously

Sorry for the miscommunication All this new info just points to a rich condition. That poping is unburnt fuel, hard starting when warm - too rich, leaning it out by turning off the gas (sound similar to a "flooded" engine clearing technique?) to get it running - too rich. Not going past 1/2 throttle at all - way too rich Main. How many times have you posted this on the "other" boards and nobody could help you?. Sounds pretty simple to me. My honest opinion is this - get rid of that carb for now and remount the stock one. You have over-carbourated your motor. Your motor dosn't have a need for it yet. Get a pipe, drill a few holes in the lid, bolt in a Boyesen Rad - then maybe try it again. Its just that, unlike cars, a bigger carb on an ATV, especially a pinger, is NEVER the first mod you should go with. Just as a side note, I've attached the jetting chart to help show the different carbouration components so you can see why its running ok at idle to 1/4, and not above. Your messing with the clip has leaned out the low to mid enough to get it running because it keeps the needle in the mainjet longer, which lets less fuel into the charge.

[Memphis]

Many younger aged people on the 3 boards, so far you guys have been extremely helpful.

I was going to attach the mod list in my previous post but I guess it didn't work for some reason?

Here it is typed out:
PB Phantom Exhaust (right bend)
30mm OKO CPW Carb
No Airbox Lid
Uni Air Filter
Vito's 1/2" Reedspacer
Boyeseen Pro Series Reeds
Bone Stock Cylinder /w fresh rebuild

Personally from just revving it through 1/4 throttle I think my pilot jet is a tad lean, but what really gets me is why it ran fine previously. The only thing I can lay the blame on is either the rebuild or the reeds that I put in. They are the only 2 things I changed...

So far comments have been helpful, thanks 3ww

[Wickedfinger]

You need to get a hold of some lower jets friend ..... then repost. You also could have included ALL of that motor mod info FIRST!!!!!!!!!!!. You're going from a 26mm carb to a 30mm. It dosent seem like much, but on such a small motor its a huge difference. BTW, Did you mount the reed spacer before or after the cage?.

[Memphis]

After the cage, I heard it makes a difference, and the reason I have the spacer is so the float bowl will clear the clutch spring on the case. I can't use the stock one atm, the floats are broke = Needs to be rebuilt.

[Wickedfinger]

One side the spacer give you more bottom end the other, top end.

[Memphis]

Yes, I know that, but I also heard running the spacer before the cage (Intake, spacer, cage) can lead to major jetting issues, which I seem to be having anyway hahaha. The placement isn't that huge of a concern anyway because the gains are so minimal.

[Wickedfinger]

Get those jets ........ let me know then.