well in my ongoing quest for knowledge, I did a little browsing around and have found some comments that lead me to believe that the mikuni 45mm carb is gravity fed and does not need the fuel pump.. the bike I have still has a fuel pump. don,t know if it is hooked up but if I can remove it, I would like to.. Was wondering what you folks thought about that? Also was wondering If you guys have any recommendations on a service manual thats worth a crap, the owners manual is just about useless

Welcome to the Clinic Flash....below is a manual site if you cant find the service manual let me know.....about the 45 ...well just my opinion but if you are not going to build the motor up its a waste of money if you want to get rid of the pump because its another chance at pump failure ...I think Doc wrote an article on how to put in a vacuume feed system its in the Tech section here under fuel pumps ...my .02$ worth anyway....Coug Edit: dam rugh morning here

http://www.paulmilner.com/pm.htm<br><br>Post edited by: Cougar, at: 2007/07/16 08:34

If you do the 42 or 45 you do not need a fuel pump.

You will need to vent the tank better than the stock configuration. You can do this by venting the gas cap or enlarging the current tank vent ... or both. I drilled out the tank vent.

Although a lot of folks put on a hi-flow Pingle petcock, if you've ever disconnected the tank gas line with the stock petcock still on you'll quickly realize that the stock petcock is more that adequate.

Doc

Man you guys are awesome, if you were any faster you would go back in time I just read the post on the gas cap mod and will give it a shot..
Cougar, I bought this bike with all the extras on it. haven't checked it out yet but am guessing that the fuel pump may be disconnected electrically but I really don't know. I have only had the bike 2 days and I have a lot to learn as it's been several years since the last one. (had a couple of young ones and wanted to make sure they got raised),,
Doc, thanks for the info, the fuel pump will be gone shortly, if the fuel pump is still hooked up will it damage the carb? also where is the existing tank vent?<br><br>Post edited by: flashback, at: 2007/07/16 09:17

It won't damage the carb .... you're just getting more pressure than necessary. I belive the pump maxs out about 2.5 psi.

The tank vent is at the front-side of the tank. It has a hose connected to it.

Doc

Flashback,
I've been running pumpless for about 2 1/2 months now with the stock carb (replaced the needle valve) and the only drawback I've experienced is I need to switch to reserve before the fuel light comes on. Don't know if this is a venting issue or not; haven't vented the cap and still have the vent tube attached to the tank vent. I asked about this (if it's normal or not) and someone on the RSR forum suggested removing the petcock and shortening the brass feed tube that extends into the tank. Haven't done it yet, but it makes sense.
As for a service manual, I went to the local dealer and bought the factory (Yamaha) manual. I can't say it's the best manual I've ever seen, but it's definitely not the worst either. But it is kinda pricey; I think I paid about $58 for it a year ago.

In case you haven't seen or read it yet, here's the link for going pumpless;
http://roadstarclinic.com/content/view/163/96/

Good luck and welcome to the clinic!!

In The Wind,
Aaron