Triumphrat

SprintRide · 01-25-2003

Hey guys...not to burst your bubble, but NGK plugs are opposite of what you think....10 is coldest 1 is hottest, never seen a 1 though. As for jetting, the needle affects mixture in the bottom half of throttle only, whereas the main affects mixture through-out the entire band. shimming the needle willnot affect top-end, you will need a larger main jet. I have a '96 Sprint myself and am going to rejet to a one size larger pilot, and two sizes larger on the mains...then get the idle CO level set to 2.0 +/- 0.5. If you do something similar it should work well for you. Cheers

j98sprint · 01-25-2003

Sprintride,

Thanks for the input. If you've done your needles can you give me some pointers and things to look for. I want to back up a little here.

My Sprint 900 runs great up and down the throttle, no pinging or popping, gets the expected mileage, starts easy, uses no oil and is quite fast. I have the JET-HOT metallic-ceramic coating on the inside and outside of the stock headers and am running the stock mufflers. I've reset the idle air screws 2 1/2 turns out to get the CO near 3 1/2% (I do not have an EGA). I also have a K&N air filter. I have 50,000 miles on the bike

Again, I'm looking for assistance in the placement of the needle shims to just fatten her up. I can get the carbs in and out, no problem, done it a few times.

Thanks, j98sprint

SprintRide · 01-25-2003

J98,

once you have your carbs out, remove the covers one at a time. It shouldn't ake a difference if you mix the springs and slides up between carbs...but all things being equal...I'd prefer to keep all the parts in the same spot that they came from...

once you take the springs and slides out, the needles will literally fall out of the slide if you turn it upside-down...don't let them fall too far. You will want your shim to be really no thicker than 0.5mm (anything more than that will cause it to idle on the mains to much and make it rich) the shims need to be a specific diameter also...just big enough on the inner to slide up to the E-clip but not be sloppy. Just small enough on the outer to fit in the recess in the bottom of the slide if your slide is so equipt. one final point of note...when you reinstall the carb cap, the diaphragm around the slide must stay in the grove around the top of the carb...otherwise you will lose vacuum and the slide will not open properly. After that reinstall and have fun...you might have to reset the idle air screws some depending on your altitude, temp and humidity...shouldn't be a big deal probably no more than a 1/4 to a 1/2 turn back in....make sure you sync your carbs after this and do it any other time you take your carbs apart...cheers and let me know how it turns out..

j98sprint · 01-25-2003

Sprintride,

That's just what I'm looking for, many thanks. I guess the needle has only a single groove for the e-clip, not several grooves in order to move the position of the e-clip, thus raising or lowering the depth of the needle, is that correct? And where do I get those particular shims?

I'll be doing this within the next month. I'll let you know how it goes.

About your Sprint, how's it treated you? How long have you had it?

Thanks, j98.

j98sprint · 01-28-2003

Deos anyone know where to get the carb needle shims?

Slinky · 01-29-2003

On bikes with non-adjustable needles I have used plain washers in the past to shim needles.

Either small metric washers (about 3mm?) or BA series washers , whatever is the best fit.

SprintRide · 01-29-2003

J98,

Sorry for the delay in responding...we get our needle shims at a hardware store. They have a inner diameter of 2.65mm and an outer diameter of 6.25mm and are about .5mm thick. I've had my Sprint for a year and a half and she treats me very well! Almost as well as my girlfriend, so I guess I am twice blessed....I have 24,000 on her ( the bike that is ) and currently am getting ready to mod it out.

Cheers

SprintRide · 01-29-2003

J98,
Actually use a shim with 3.0mm inner and 6.8-7.0mm outer then you won't have to drill the inner to size.

Cheers

01-29-2003

Radio Shack has a bag of washers that will provide the right size.

Ride with great verve,
the Craze

jefftarlton · 01-29-2003

I've used 4-40 washers in the past. Any model airplane type hobby shop has these. Don't use more than one under each needle.
Don't remove the slide diaphragms unless you have to in any carb job. They are thin and tear easily. Price them next time you're at the dealer.
Jeff