1980 450l help

[ehuhn]

My son just bought a 1980 450l and is looking for some information. It has the air box removed, and clamp on filters installed. I'm not sure what the stock jets were and what size is recomended with the aftermarket air cleaners. I believe it is a mikuni carb, but not sure what style jets are in it. I don't mind opening the carbs and rejetting, if I have a starting point. Or am I better off getting a stock air box and stock jets?

Thanks
Ed

[t3rmin]

Is it running poorly?

[ironash]

I've got one of those.

I just bought an 80 450L for my first bike last year. I ended up removing the stock airbox and putting on two cones. There was no way I was going to rejet it. I researched and found it very difficult to find jetting for a 450 or info on it. Plus it would have been a pain in the ass.

Instead I meased the air intake on the airbox at the point it connects to the carbs. Once I new that I wrapped black electrical tape around the cone filters to give the same intake area. Ran just fine and sounds throaty too because you can hear the air being sucked in.

I'd start with it being more air restictive with the tape and see how it idles/drives and slowly cut away the tape. With the cone filters and black tape it looks fine, even hard to tell its mocked up when you look at it.

My advice for the 450 would be to don't do too much too it if you can avoid it. As with me I'm growing tired and want a bigger bike, 550 or 650 this year I'm sure he will too. No sense in putting anthing other new handle bars and a few small things into this great learner/commuter bike.

[ehuhn]

Is it running poorly?

Yes. It is real crappy when cold and feels like a dead spot at wide open with hesitation.

[t3rmin]

Well your easiest route might be ironash's advice, or if you want to rejet, see this site:

http://www.factorypro.com/tech_tuning_procedures/tuning_carbtune,CV,high_rpm_engines.html

Also try the search feature for lots of GS-specific carb info.

Good luck!

[t3rmin]

Oh and don't discount the idea that maybe the carbs are just in need of a cleaning/rebuild. Perhaps the person who put the pods on *did* rejet already, but the carbs are just gummed up?

[blo]

Hi there!
Stock jet size would be around 117.5 (depending on model and year)
It could also be 115/120 but as this is the next size up/down it really does not matter that much.
I've found that the jet size depends very much on the type of pod you are using. (Assuming the BS34 carbs)
A K&N pod flows very easy and needs jet sizes in the excess of 130, whilst EMGO pods only need 122.5 - 125.

Clean out the carbs, check current jet and just try it to see if this is go or no go.

[Ludeykrus]

Hi there!
Stock jet size would be around 117.5 (depending on model and year)
It could also be 115/120 but as this is the next size up/down it really does not matter that much.
I've found that the jet size depends very much on the type of pod you are using. (Assuming the BS34 carbs)
A K&N pod flows very easy and needs jet sizes in the excess of 130, whilst EMGO pods only need 122.5 - 125.

Clean out the carbs, check current jet and just try it to see if this is go or no go.

I thought it was the other way around; don't the EMGO's flow more than the K&N's? I'm probably wrong....

[blo]

The K&N's are (by my opinion) the leading brand of performance filters.
Upside is they last forever
downside is price
They are definately more "open", that is free flowing, than EMGO.
My 450 currently uses EMGO filters that are barely less restrictive than the stock airbox.