Need Help on XJ700 in Memphis

Long Story - I picked up an XJ700 for my 19 Year Old Son about 6 weeks ago. Guy I bought it from said the carbs needed sync but otherwise it was a good running bike.

PLAN A: I bought a manometer but then figured out I did not know enough about what I was doing to get it right. Note: Bike would start up and would run but lost power when you throttled it. so I moved to Plan B

PLAN B: Took it to a reputable old bike repair shop in Memphis. They kept it for 3 weeks. Said they rebuilt the carbs but had to order the airbox parts because the bike was missing them. Called them every day after about 10 days. The mech told me that the bike was running great until it warmed up and then it would go up to 5000 rpms. He said it had an air leak in the intake manifold. Said he was trying to find replacement. Another couple of days pass and he says he went to a yamaha junk yard and got another set of manifolds because he could not find them on line. He said they leaked as well. Said when he sprayed around the manifold the idle changed and that confirmed the problem as being the manifolds. They had the bike for 3 weeks and he said they exhausted their resourses and that unless I could find new manifolds I had a boat anchor. Note it has Hitachi carbs on it.

I picked up the bike late this afternoon. When I got the bike home they did not reconnect the gas tank or the choke. The 3 hoses coming off the carbs are hanging every which way. So for the long E-Mail but here are my questions:

1. The 3 hoses coming off the back of the carbs I assume are just drain overflow hoses and just hang down. Correct?

2. The #3 intake manifold is suppoed to have a hose attached to it. Where does it go?

3. He gave me back the original intake manifolds that he took off and they look like they are in good shape. Looks like there might be an O ring on them that could use replacing. I am not sure if I can dig the old O ring out oir if it is even supposed to be able to be taken out and replaced. If yers where can I get replacements?

I apprecaite any help and if any of you are are xj700 mechanics near Memphis, let me know.

I don't mind putting a little money in the bike as it is in pretty good shape I really just want to get it running for my son. He got his hopes up when I got it and has been disappointed with every day of not having a running bike. Therefore the bike is setting in the barn waiting for me to fix.

Please help

 

Long Story - I picked up an XJ700 for my 19 Year Old Son about 6 weeks ago. Guy I bought it from said the carbs needed sync but otherwise it was a good running bike.

PLAN A: I bought a manometer but then figured out I did not know enough about what I was doing to get it right. Note: Bike would start up and would run but lost power when you throttled it. so I moved to Plan B

PLAN B: Took it to a reputable old bike repair shop in Memphis. They kept it for 3 weeks. Said they rebuilt the carbs but had to order the airbox parts because the bike was missing them. Called them every day after about 10 days. The mech told me that the bike was running great until it warmed up and then it would go up to 5000 rpms. He said it had an air leak in the intake manifold. Said he was trying to find replacement. Another couple of days pass and he says he went to a yamaha junk yard and got another set of manifolds because he could not find them on line. He said they leaked as well. Said when he sprayed around the manifold the idle changed and that confirmed the problem as being the manifolds. They had the bike for 3 weeks and he said they exhausted their resourses and that unless I could find new manifolds I had a boat anchor. Note it has Hitachi carbs on it.

I picked up the bike late this afternoon. When I got the bike home they did not reconnect the gas tank or the choke. The 3 hoses coming off the carbs are hanging every which way. So for the long E-Mail but here are my questions:

1. The 3 hoses coming off the back of the carbs I assume are just drain overflow hoses and just hang down. Correct?

2. The #3 intake manifold is suppoed to have a hose attached to it. Where does it go?

3. He gave me back the original intake manifolds that he took off and they look like they are in good shape. Looks like there might be an O ring on them that could use replacing. I am not sure if I can dig the old O ring out oir if it is even supposed to be able to be taken out and replaced. If yers where can I get replacements?

I apprecaite any help and if any of you are are xj700 mechanics near Memphis, let me know.

I don't mind putting a little money in the bike as it is in pretty good shape I really just want to get it running for my son. He got his hopes up when I got it and has been disappointed with every day of not having a running bike. Therefore the bike is setting in the barn waiting for me to fix.

Please help

 

There's a couple places to try for hard to find and odd parts. And regular parts too. First is (of course) Chacal who is on this site and is really good. Then there is Partsnmore.com. I got a set of carb-to-engine boots from there for $90 a couple years ago, now they're $100 which is still really good. Then there is oldbikebarn.com, never used the guys on here seem to have mixed emotions about them. Hope this info was helpful. You should put up some pics of the bike man.

 

The o-ring on the intake manifold does not come out. Remove all of the old gasket material with a gasket scraper then use some sand paper 600-800 grit sitting on a piece of glass, (used for a flat surface) and, sand the manifolds flat. You can then make a new gasket with some blue gasket material. As far as the small hose attachments on each of the intake maniflolds, 3 of the small brass tubes should be capped shut. the #2 is attached to the petcock to help feed the carbs fuel. If you can locate the air leak on any of the boots, you should be able to seal them up with some RTV. Hope that helps some!

Cheers
Ken

 

how does it idle? was it a good, smooth, idle? while you have the carbs off and replacing the intake seals, you can bench sync the carbs to get them close enough to put on the bike to and get it to run.
I use a twist tie with the paper removed.

Adjust the tick screw on the airbox side of the carbs to open #3 enough to put the tie under the butterfly. back the screw out just enough so that it catches, but allows the tie to move with a little resistance. remove the tie and go to #4 (as you look at the butterflies, 1 is on the right, 4 on the left).
Adjust the screw between the butterflies of 3 and 4 so that the tie slides with comparable resistance to 3. double check against 3 if you like.
Move to #1 and adjust the screw for 1 and 2.
Finally move to 2 and adjust the screw between 2 and 3.
hit #1 again to make sure it's still set.
this will allow you to start the bike and it should run. it may not be perfect yet, but it will be close.
while you have the carbs off, you should do a clunk test.

look at the airbox side of the carbs... you will see 4 brass slides in each carb. with the carbs level, lift each one up to the top of the carb venturi and drop them down. each one should make a very good "clunk" sound.
if the carbs were rebuilt by a good shop, they should pass with flying colors.
if they don't, we can help you with that.