Xj650 intake manifolds

First full riding season with my xj650 which last year i restored. The bike had trouble idling from the start, it did sit for the last 10 years, and last week i decided to take of the problem once and for all. I cleaned the carbs until they shined, inside and out. The air filter, oil and filter, plugs (properly set ) tank, petcock were all changed along with many other new parts. I put the carbs back on and still, wont run at idle, and when i put the choke on a little, it takes awhile for the RPM's to fall back down after revving. I checked the plugs and 1,2 and 4 were sooty, 3 was fine. So i figured that i need to adjust the mixtures. The only thing i didn't mess with on the carbs. When i was starting it up just before messing with the mixture, i noticed the intake manifolds had finally given out and cracked to shit. Ebay offers intake manifolds for the xj650 for $100 brand new. Kinda spendy i thought. Then i saw manifolds for 86-90 yx radian 600. They look so similar it's scary but these manifolds are $45 brand new. Even the engine and carbs look extremely similar. The only difference is that the radian's manifolds angle in opposite directions than the XJ's but i figured just swap the left side ones to the right. Does anyone know if these are interchangable parts? Also has anyone ever put RESTORE engine treatment through their bike, and if so, did it help? THANKS

 

What year/model of XJ650?

I've got a set of used ones that will fit the 82 and I believe 83 (not 80-81) Maxim. They're in much better shape than I thought when I ordered new ones. Turns out they are very flexible and the cracks are external surface only.

$30 shipped lower 48. You will need to get gaskets.

 

I keep my rubber manifolds like new by dipping my finger tips into a quart of oil, and litterally rubbing them down. I do this about twice a year, and after 25 years mine still look new. Rubber is porous, like skin it likes to be lubed every once in a while, and absorb up some lube.

 

Hello,and welcome,xjyamaha. What year is your 650? I have a spare set of intake manifolds from my '82 XJ 650 Maxim that are still very serviceable...Cover shipping $,and they're yours. PM me if you're interested. These manifolds will only fit YICS models (1982 and later).
Regards,
Dan

 

Putting oil on rubber? Yikes! Oil (a lubricant that causes rubber to swell with exposure and degrade) certainly will make the rubber look new for a while but it will destroy the rubber. While I will agree that rubber needs lube now and again (preservative is probably a better term), there are chemicals for that purpose available. I would steer well clear of using oil on rubber, except where specified on engine assembly. What type of oil are you using Russxlr? I hesitate at using the oil/rubber trick as I find, time after time, rubber components exposed to oil that have fallen apart or become disfigured (spark plug boots, selector shaft bellows, power steering bellows, etc). I am curious to know if you have some knowledge I lack.

 

I would have to agree with Robert on this one. Using oil to prevent cracking, my seem like a good idea to keep them looking new, but will deteriorate the rubber in time. I wouldn't recommend it.
Might I suggest using Goop (sold in most hardware stores, Menards, Home Depots, ect.)
What I did was remove the rubber manifolds from the bike and completely coat the outside of them with Goop and let dry for abut 1/2 hour. Then they are dry enough to handle and install.
Goop is like a silicone when it goes on and dries like liquid rubber. It is also nice and shiny when it sets up, so it makes the intakes look better. A thin coat is all that's needed to seal the intakes.
It's a cheap alternative to buying new ones and has worked for years on my bikes.