classic motorcycle forum

Motorcycle Discussions => Japanese Bikes => Topic started by: Stitch on May 25, 2013, 12:59:28 PM

Title: Mikuni CV carb strip
Post by: Stitch on May 25, 2013, 12:59:28 PM
My old GS1000g has been parked up in the garage for 15 years and I've finally got to it. The engine turned over so that was a start. I knew the carbs would be a mess so I've removed them and started stripping them. I assume I'm going to have to strip them into individual units, The diaphragms are OK, and I've removed them, the main jet, jet needles, floats, pilot jets BUT how do I get the float jets out and how do I clean the choke tube from the float bowl. I had to drill out the float bowl choke tube !  when I say a mess the float bowl insides were brown and the needle jets were a green/black slime. :(
Title: Re: Mikuni CV carb strip
Post by: wetdog on May 25, 2013, 02:10:57 PM
try getting them sonic cleaned and dont mix up the parts , the piolt jets (needle) can be difficult to reset and the tip is often missing
Title: Re: Mikuni CV carb strip
Post by: Stitch on May 25, 2013, 06:16:41 PM
The needle jets came out quite easily and the tips are fine. Other people have mentioned sonic cleaning, but at £20 per carb is it worth buying a cleaner ? I have no experience of sonic cleaning, is it up there with microwave ovens and mobile phones ;-)   
I counted out the number of turns on each pilot jet at 14 1/2 turns or tight and 1 1/2 out. many thanks for you reply. Any other advice would be more than welcome .
Title: Re: Mikuni CV carb strip
Post by: Bomber on May 25, 2013, 11:48:33 PM
Hahaha John... I already told you! Stitch is an old mate of mine Wetdog... humour him
Title: Re: Mikuni CV carb strip
Post by: Bomber on May 26, 2013, 12:28:55 AM
John, I had a twin choke webber sonically cleaned.. tbh it didn't make a sh*t of difference. I finished up cleaning it myself and then getting an expert to do the refurb
, although it looked a lot better after Sonic Cleaning!
Title: Re: Mikuni CV carb strip
Post by: wetdog on May 26, 2013, 09:46:49 AM
you could always try a set of the pre cv carbs , i find them easyer to work on , im not a fan of the cvs and can be expensive to rebuild , i had a GS 1000 here and it was fitted with 4 amals and it went very well but it had been tuned , the G was one of the best with the shaft i think .
Title: Re: Mikuni CV carb strip
Post by: Bomber on May 26, 2013, 11:26:49 AM
I think the pre CV's are a couple of mm less if I'm not wrong, but like you I'm not a fan of CV's
Title: Re: Mikuni CV carb strip
Post by: Stitch on May 26, 2013, 11:54:39 AM
Why am I not surprised you turned up on this site Frank, I'm not that keen on cv carbs either, I think they were over engineered for the sake of it, but that's what is on the bike and I'd like to keep it standard if possible.
Title: Re: Mikuni CV carb strip
Post by: murdo on June 15, 2013, 09:04:51 AM
Then soak them in thinners for a couple of days and blow out with air.

Below are pictures of the fuel bowls from my Yamaha YDS5 250. These were so bad I had to bead blast them before soaking in the thinners. Come up good afterwards.

Title: Re: Mikuni CV carb strip
Post by: paulos on June 23, 2013, 09:16:57 PM
I'm guessing your carbs are all sorted now but follow this tutorial you wont go wrong (make sure you do a full carb strip down, after 15 years and a new oring kit ),http://www.mtsac.edu/~cliff/storage/gs/Mikuni_BS-CV_Carburetor_Rebuild_Tutorial.pdf

GS electrics are notorious so go through all the grounds and also look at some other mods such as swapping the RR for a recommended after market or Honda RR, as well as a coil relay mod for better spark.... TheGSResources forum has a tonne stuff there specific to your bike