carb swap

razz1969 · Posted: Fri Jul 10, 2009 10:15 pm Post subject: carb swap

I recently broke an easy out in my carbs (trying to remove a striped pilot screw). So I ordered a set from a salvage guy in Fort Worth. He said that they came from a xj750, But when I received them the next day, they were Munuki's where mine are Hitachi's. Question is can I use these on my bike without harm.(It does run with them) Also should I take the jets out of the Hitachi's and put them in?....If they fit That is. Any advise is very appreciated because I have to get this bike back on the road. It is my daily driver.

86xj700_indy · 4th gear Joined: May 10, 2009 Posts: 152

you should be fine with either carbs with no problems

MadMaxim85 · Posted: Sat Jul 11, 2009 3:48 am Post subject: Re: carb swap

Aren't the mikuni's too long in comparison to the hitachis?

wingnut325 · Posted: Sat Jul 11, 2009 5:21 am Post subject: Re: carb swap

Has anyone ever successfully swapped the Mikunis onto a XJ650? Will they even fit?

razz1969 · Posted: Sat Jul 11, 2009 5:33 am Post subject: Re: carb swap

They are about 1/4" longer but they fit with no problem. But should I use the jets out of the Hitachi's if they fit?

wingnut325 · Posted: Sat Jul 11, 2009 7:07 am Post subject: Re: carb swap

I know the Hitachi's have 120 mains in the 750 thats here. I do not know if they will swap. Best way is to get 4 120s for the Mikunis from our parts guy. They are not expensive. Do you know what pilots are in the Mikunis? Those need to be matched also. You may have to experiment with the jetting a little to get it right. What did the new set come off of? I'm wondering about the needles. If they came off of another XJ it should work out. Good luck and let us know. I have a set of Mikunis from a 79 1100 and was thinking about trying to fit them to the 650.

razz1969 · Posted: Sat Jul 11, 2009 10:11 am Post subject: Re: carb swap

It starts ok and revs really good, still playing with the idle. The fule tranfer pipe o-rings are leaking so I have not driven it yet.

wingnut325 · Posted: Sat Jul 11, 2009 10:33 am Post subject: Re: carb swap

Had that leak on the last set of Hitachi's. Went down to the local hardware store that had a good o-ring set collection. #7s matched up really well. Think they were 16 cents each. More trouble to break them down for the change than anything else. So am I understanding this right. You could have either Mikunis or Hitachi's on a 750 from the factory?

razz1969 · Posted: Sat Jul 11, 2009 10:40 am Post subject: Re: carb swap

so standard o-rings will fit? the ones on Hitachi's looked flat.

RickCoMatic · Posted: Sat Jul 11, 2009 11:21 am Post subject: Re: carb swap

The Mikuni's probably won't fit. I think the Mikunis are on 550's, 900's, and Maxim-X Bikes.

If they DO fit, they will likely need to be Re-Jetted.

O-rings in Metric Sizes are available in Hardware Stores which have well-stocked Plumbing Supply's with an O-ring assortment in Pull-out Drawers.

razz1969 · Posted: Sat Jul 11, 2009 1:57 pm Post subject: Re: carb swap

thanks rick.... what size do you recommend?