decompressor starter

danxs650mass · Posted: June 5, 2009, 1:44 pm Post subject: decompressor starter

hey guys i bought a bike in boxes and it has this thing i never seen before so i have some questions like where on the handle bars does this lever mount and what do i need to do to make it work ? i know this alot to ask but any info will help thanks the guy i got the bike from says all you do is pull the lever and the bike starts right up

KYLEPRESTON · Posted: June 5, 2009, 3:32 pm Post subject: Re: decompressor starter

it goes on the right handle bar and there is a cable to make it lift(mikes sells the cable). basically what happened was you pull the handle when you start the bike. it releases the compression from the cylinder making the starter work less. the starter on the 72 was undersized for the bike.
the only one I have seen complete was at roy fisks a few years back. if you ask roy he might be able to give you some more insight.

cheers Kyle

nudude53 · Posted: June 5, 2009, 9:28 pm Post subject: Re: decompressor starter

You can put any XS starter on your bike and it will work but you will need a handle switch with the starter button in it ('74 up) if you want to eliminated the decompressor rig. You can put a regular 4 bolt cover cap over the valve opening but you can't just use the decompressor lever for a starter switch, there is a contact in there that won't let it engage the starter without the cable attached. If you decide to eliminated the decompressor set up let me know, I'd like to have an extra lever switch for a spare.

danxs650mass · Posted: June 6, 2009, 12:06 am Post subject: Re: decompressor starter

hey guys thankyou for the info i think i will try to take it off the bike does any one know if this will affect the kick starter i dont think it will but im guessing on that

nudude53 · Posted: June 6, 2009, 12:16 am Post subject: Re: decompressor starter

It won't affect the kicker at all

pumps · Posted: June 6, 2009, 12:32 am Post subject: Re: decompressor starter

I don't think it will affect the kicker.

JeffM · Posted: June 10, 2009, 2:44 pm Post subject: Re: decompressor starter

---there is a contact in there that won't let it engage the starter without the cable attached---

Nudude, thanks for that key piece of info! I haven't got too deeply into the starter on my xs2, may be worth a second look now. I was planning on just eliminating the starter until the bike chucked me down the road last fall and buggered my knee. Evil or Very Mad

nudude53 · Posted: June 10, 2009, 3:35 pm Post subject: Re: decompressor starter

Jeff:
I learned about that the hard way after disassembling the switch about 3 times thinking that it was a dirty contact somewhere. It wasn't until after I decided to fool with it later and continued with the rest of the restoration that a new cable arrived from Mikes and when I installed it and pulled the trigger it rolled right over. I never saw a saftey contact inside the handle switch but I can only assume that there is one hidden in there for that very purpose. Of course if it hadn't bucked me off last July and tore me all to hell I wouldn't have had the chance to rebuild the bike anyway. Funny how things work out.

Another note on the de-comp starters:
I read somewhere a while back that when Yamaha originally put the electric start on the XS2 and TX models the starter spun faster than the ones they used on the '74 and up models, hence the decompressor to take some of the load off of the starter. But when I researched it further I could only find one part number for the starter (306-81800-12-00) which covers all years. So if you do need to replace one it's an easy fix. Apparently the original starters were superceded by the new number.
I have no intention of changing the switch set-up on my TX, I like that little trigger under the brake lever, it invites a variety of questions from people to which I have stockpiled a variety of very stupid answers. Twisted Evil

danxs650mass · Posted: June 11, 2009, 10:12 am Post subject: Re: decompressor starter

some one said too switch starters from a newer bike so i have a 77 parts bike what a surpize i had when i took the starter off and all the oil came out of the motor a little diff than other bikes i have worked on i guess i have alot to learn about these 650s

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