New to bikes & need some advise

OK so here the deal. I have a 1983 xj750 seca that doesn't like to start cold without carb clean and idles very rough once started. Once its warm it will start ok but will idle rough or high. Weirdly it has done both. I have adjusted the idle screw and thats seemed to help the idle when warm. Also when i rev the engine it sometimes holds at 3k rpm and either will drop slowly back to 1k rpm or do the complete opposite and start to rise. I kill it at 4k.

Here's the question.

1. Should I rebuild\clean\sync the carbs?
2. Should I get a gasket replacement kit?
3. How can I tell if I need new jets in the carbs?

Thank you for any advise you can provide me. This is my first bike and it has been a while since I did any mechanical work.

 

A proper carb clean & sync should solve most of your problems, you shouldn't need gaskets if you leave the boots on the head, sounds like the enrichment dept' is partialy blocked & the slides are sticking.
Follow RickCoMatic's post on carb cleaning & sync', send him a PM if you can't find it.

 

Great Thank you.

 

I agree with wizard, you need to get those clean enough to make a marine corp drill sgt happy.

 

Get those things clunkin'

 

deadulus, your sig is freakin hilarious!
everytime you post I see that and laugh.

sorry for the hijack

 

OK so couple things i found when taking apart the carb.

1. The throttle plates are not lined up.
2. The #2 carb float hinge frame is broken.
3. All the Jets were dirty.
4. Three of the four needles look broken.

Hopefully I can replace the #2 carb and get new needles for the rest.

 

I'm surprised it ran at all!

What do you mean the needles "look" broken? Are they bent? tips deformed in some way? Can you post any pics? JB weld may be able to fix your problem as far as the hinge frame is concerned. I have a set of hitachi carbs off a 750 (I think it was a maxim, not a seca, let me know if it will work with your bike and if you want anything) They are in pretty rough shape, not all the pieces are there, but you might be able to use some of it. Id be happy to just send you the #2 carb and the accompanying pieces if you pay for shipping. I'll clean it up for you!

Let me know.

 

looks like you have a lot of work to do on those carbs.
good luck!

once you get them cleaned up, you will be amazed at how well it will run and how good you will feel that you did the work to make it run like it will

 

Madmaxim85.

I am surprised that is ran also. I did go out an get some JB weld it was a fairly clean break so i think it will work. The needles are dis-formed. looks like the rubber broke down. I have some pics attached of the points. Best i could get my kids hide my real camera. These are off my phone.

I appreciate the offer of the carb. let me see if i cant salvage this one first.

I think i can get the needles from Bikebandit

How do i attach an image?

 

when you click "post reply" there is a picture of a yellow mountain. you can link to them there.
you will have to upload it to photobucket or tinypic and link it.

 

I did some more cleaning and the heads of all these were stuck in the opening of the bolt. I have to find 3 of these. looks like bikebandit doesnt have them. Anyone know of another site I can order them from.

 

old bike barn has a kit with needles, seats, and gaskets for like 20.00 usd

 

Yeah i have not had good luck with old bike barn. Any other good places.

 

Chacal should have them. Or motorcyclecarbs.com I got some from there. Or even an ebay seller.

 

Personally I have seen outstanding results from Chacal (XJforever.com)
He has had every odball part I have needed and it arrives in my mailbox before the USPS knows he sent it.
You can find him here under supporting vendors.

 

OK so the novice broke his carbs and now i need a new rack. I broke the float hinge pin upright on two carbs. so anyone know if an xj900 carb set will fit an xj750? or know anyone who has an hsc32 carb rack to replace mine.

 

Well,
I am on the road thanks to RickOmatic. Without him i would have never gotten on the road.

Now i am tuning the fuel mixture. Does anyone know the correct colortune tool thread size?

I did a plug chop and it looked ok but i think i am using too much fuel. i have gone about 75 miles and i have used about 2.5 gallons which would put my around 30 mpg. Should it be higher?