Fuel Filter/ carb issue

[MongoReturns]

I believe the only difference is the amount of outlets, since I haven't bought one I can't say for sure.  Why not give them a call?

Back of mikuni package says it's for df62-702, df62-705, df62-706.  So also guessing same internal parts, different # of outlets.

I actually thought I was the last to rebuilt the OEM pump, but you win.  I think ethanol has something to do with the deteriorating, but I'll soon be on my THIRD 1098 tank due to expansion.  I'm sure you've checked to make sure no kink in the fuel line loop?  That happened to me years ago, I just put the tank down easy then peak under to make sure no kinks.  And to make sure the fuel line isn't contacting the rear cyl.  That just never seemed very safe.

Come to think of it, its seemed my top cyl has been running rather hot lately too.  Ugh.

[He Man]

Thats why im thinking about redoing the fuel line.

[koko64]

Good idea He Man. It's good to replace fuel lines every five years or sooner if they have deteriorated due to heat, fuel additives, etc.

Some hoses harden in no time at all . I changed to that fancy transparent hose recently because some new hose went very hard and brittle within a month. It looked ready to fracture with vibration!

[He Man]

how much hose you got left? i doubt i could ever use 25 feet. and how is it holding up to heat?

[koko64]

Just a tiny off cut.
Seems to be ok. Local Yamaha dealer had it and said it was the best hose they have had.

[He Man]

rebuild kit came in today from bike bandit, its a genuine mikuni!

now to install it and put everything back together...


im guessing its a good idea to just put everything together and fire it up from a bottle of gasoline and let it idle for a while before its good to go? i dont want to patch it all up and figure out its no good

[MongoReturns]

rebuild kit came in today from bike bandit, its a genuine mikuni!

now to install it and put everything back together...


im guessing its a good idea to just put everything together and fire it up from a bottle of gasoline and let it idle for a while before its good to go? i dont want to patch it all up and figure out its no good

I didn't.  Just make sure you put the pump back together right - I only realized when it didn't fit back in it's space.

[He Man]

well i put the fuel pump together and hooked everything up and ran the bike from a bottle of gasoline placed above the carbs. (well above the carbs).
i pinched the vaccum line for the petcock and bypassed the fuel filter.

while cranking for about 1 straight minute, i killed the battery. the bike kinda wanted to start.

I cranked open the bowls of the carbs and gas came out the right carb, but not so much the left carb.

The left carb ironically is the one that connects to the rear cylinder (which was getting stupid hot before)

The carb checks out to be mechanically fine.

Question: Does one carb fill up before the other, there was no way the carb was full after cranking for 1 minute. do i need to prime the pump first?

[Howie]

Either the mesh filter in the carb intake is clogged or the needle an seat are sticking closed.  The screen does affect both carbs though.  Ah, look fir a restriction in the tee

[koko64]

Most have a T piece between them, but if the bike is on its side stand then maybe.

Thats a lot of cranking without a start. I suppose its primed now with all that cranking. Mine didnt take too much to start. A full tank may help prime it better, but if there was fuel in the bowls it should have started.

Try a full tank next time and watch the lines for fuel flow. Mine courses thru quite impressively.

You seeing the fuel run thru the clear hose when you crank it? When I turn on the tap the hoses fill.

[He Man]

Either the mesh filter in the carb intake is clogged or the needle an seat are sticking closed.  The screen does affect both carbs though.  Ah, look fir a restriction in the tee

which needle?

I havent taken a look at the mesh filter. i never opened it up that far.

there is no restriction at the tee that i know off. ( i removed the tube and blew air into it, seems like i am getting carb vapor (or just the rampant smell of carb cleaner that can melt brains) from both carbs equally.

[MongoReturns]

I'd give the bat a good charge & try again.  For some reason, my bat will crank hard & fast but not have enough juice to power the plugs.  Throw it on a charger, BANG starts right up.

[Howie]

The thing connected to the float that allows fuel into the bowl.

[koko64]

He Man, hows it going?
Find a fuel blockage? Pump and tap ok?

[He Man]

okay put everything back together. and tightened the belts (they were make the beast with two backsing LOOSE!) of course, id venture to say that the 12k service was NOT done as the owner said because how the belts got that loose? easy, it wasnt serviced. :p

anyway, with a new fuel pump diaphgram the bike is running good and idles great. had it sitting and idling for 10 mins with no issue and held the bike at a high RPM for about 1 whole minute (headers getting red) with no issue. Im trying to recreate the heat that the bike seemed to have failed in the last few times and im having my buddy ride the bike around in city traffic for an hour to make sure there are no issues.

AFAIK, the pump seemed like it was the issue the whole time as i found nothing else wrong. Took the carbs apart and they looked good. the emulsion tubes are kinda worn and could use a rebuild soon.