1979 suzuki gs425e

[pete]

I'm not sure what jets are in the 425 carbs, but a lot of Mikunis tend to go up in increments of 2.5 so you'll probably add 5 to what's there now...

[lmrmllr89]

Where can I find what size is in there now.........I ask a lot of questions (probly dumb ones)......but only cause I really don't know a lot about jetting......thanx in advance.....

[SVSooke]

http://members.dslextreme.com/users/bikecliff/images/carbspec_float_height.html

That info should be here.

[lmrmllr89]

Well after much thought I went ahead and bought this exhaust....http://item.mobileweb.ebay.com/viewi...d=250973665699.......and ordered the jets I think ill need.......I found the size stamped on the old jets......it was 117.5....

[Midwest FZ Rider]

Nice grab! That seems like a really good price!

[lmrmllr89]

Yea that's what i thought......compared to a new one at least...and was cheaper than a original one was

[pete]

Nice! Looks to be in good condition too!

Give the stock jets a go first, but make sure you do plug chops to make sure you're not too lean. Too rich won't do damage but will rob you of available power, whereas too lean will cause it to run hotter and worst case is holes in the pistons.

[lmrmllr89]

probably a dumb question....but what is a plug chop......not sure im familiar with that term and just want to be clear on it....

[cowboyup3371]

Plug chops are essentially when you are driving along, say around 5000rpm, hit the kill switch (without returning to idle), coast to the side of the road and look at your plugs to determine their color. I haven't done it yet, more out of nervousness, but hope to this year.

Read this article on Basscliff's site.

http://members.dslextreme.com/users/bikecliff/images/highest_rpm_plug_chop.html

[pete]

Plug chops are essentially when you are driving along, say around 5000rpm, hit the kill switch (without returning to idle), coast to the side of the road and look at your plugs to determine their color. I haven't done it yet, more out of nervousness, but hope to this year.

Read this article on Basscliff's site.
http://members.dslextreme.com/users/...plug_chop.html

Yep, except ignore RPM's

Plug chops are all about air/fuel mixture at certain throttle openings, so you'll need various positions marked on your right grip with masking tape so you can chop at the different throttle openings.

Alternatively, you can get a Gunson Colortune and do a lot of it in the garage

[cowboyup3371]

Thanks Pete. Though one question, how well does that colortune work as I read on here that some folks don't get any good readings from it. Is it maybe a bike specific thing?

[pete]

Thanks Pete. Though one question, how well does that colortune work as I read on here that some folks don't get any good readings from it. Is it maybe a bike specific thing?

To be 100% honest I haven't actually had time to use mine yet... but I can see how it would be difficult on some bikes. They do provide a periscope type tube with it to make it easier to see though.

If you go by the various Youtube videos around the place it should be very handy.

Cross fingers I might get to find out this weekend... I intend to post video when I do finally get to try it!

[lmrmllr89]

So I ordered my jets from this site http://www.motorcyclecarbs.com/Mikun...02_221_C20.cfm.

I saw that in some sizes they offer an aftermarket one for about two dollars cheaper.....anyone have any experience with the aftermarket ones....are they a similiar quality as the more expensive ones?

[pete]

I've only used genuine so far myself, but of course I haven't done a lot yet, but I have seen it said to stick with genuine... never used those aftermarket ones though so can't really comment too much...

[lmrmllr89]

I got my tank back!!!!!!!!