well today sucked... Got the estimate from the shop

Picked up a 1981 Suzuki GN400 as my first bike for a relatively low price... knew I'd have to put some money and work into the bike before I got it up and running, but I had no clue a diaphragm would cost $170 a long with other various parts for the carb such as an air filter, main jet kit, pilot jet kit, o-ring needle valve, and needle valve. The total amount that the local motor sports shop is charging me is $300 dollars and that doesn't even include labor.. I picked up the bike for less than that. The diaphragm has a very very tiny tear and I'm not sure about the condition of the other parts but I'm sure they need replaced anyways. This is my first bike and I'm a college student so my budget is already restricted due school expenses... does anyone have any alternatives or solutions? Or should I just pay the price.

The carb is a Mikuni BS36.

Source the parts and do it yourself. Its not as bad as you think, and its a good learning experience (your in school, you dig that kinds stuff, right?). Plus down the road, if you go pod filters or less restrictive exhaust, you'll be comfortable changing needles and jets. There are some good Suzuki resources out there like this:

http://members.dslextreme.com/users/bikecliff/

And here's a rebuild tutorial on your carb:

http://www.mtsac.edu/~cliff/storage/gs/Mikuni_BS-CV_Carburetor_Rebuild_Tutorial.pdf

Or you could change carbs entirely and replace the CV carb with a Mikuni VM34 for the price that shop is quoting from places like this:

http://www.speedmotoco.com/category-s/74.htm

They are real cool and can probably taylopr a solution for your GN.

Good luck!

Rebuild the carb yourself. It's too simple a job to pay a pile cash for. Take it apart and get it all clean. Post pics and a needed parts in the correct areas here on DTT and we'll help get ya back together.

I was thinking about just doing it myself and it looks like I'm going to... I just can't find a diaphragm for the carb anywhere. Time is also a factor.. want to get the bike up and running before school starts in about three weeks.

Put a want ad in the buying section here on DTT.

VonYinzer said:

Put a want ad in the buying section here on DTT.

Click to expand...

Appreciate it. New to the forum if you can't tell.. lol

INDYRACER44 said:

I was thinking about just doing it myself and it looks like I'm going to... I just can't find a diaphragm for the carb anywhere. Time is also a factor.. want to get the bike up and running before school starts in about three weeks.

Click to expand...

I repaired my diaphragm with tire patch rubber and scotch weld neoprene adhesive.. total cost free.

Pm big rich

I am pretty sure that carb has the same diaphragm as an XS650 Yamaha and GT750 Suzuki and others and a replacement is available cheaply on line for about 30 bucks IIRC.

All that other jet kit stuff is probably BS too. If the jets need to be replaced, look at what size they are and order them from JetsRUs or similar. Be sure to order the correct type slow (Pilot) jets. http://pinkpossum.com/GT750/carb/BS40carbs.htm shows the different types. The difference is subtle but once you know the differences it won't be such a challenge to order the right parts.

MikesXS.com as a lot of XS650 carb parts, so check there too.

You can try JBM Industries for replacement diaphragms: http://jbmindustries.com/

That's the team I could not remember their website. http://jbmindustries.com/Yamaha650.html

Are there two threads on this subject now?

teazer said:

That's the team I could not remember their website. http://jbmindustries.com/Yamaha650.html

Are there two threads on this subject now?

Click to expand...

thanks for that source.. looks like a good alternative, considering they just sell the plastic for the diaphragm and that's all i need.