Won't rev past 6k

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evoluzione750
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Re: Won't rev past 6k

Post by evoluzione750 » Thu May 14, 2015 2:42 am

The chokes do all actuate properly, fully open and close.

I've changed the clip position to the very top of the needle, as the mains currently in it (all 97.5's) seem to be richer than the stock option. If that does make a difference, I'll get a hold of two 90's and two 92.5's and throw them in.

Image
The plugs indicate that it has been running rich. #4 was only threaded about 1/4 of the way in and probably wasn't even seeing the mixture, so I believe that's why it looks different.

To take the correct measurement of the fuel level, do you use the bottom of Mikuni as a datum, or the bend in the bend in the bowl?

I've only had enough time to get it all back together by the time the sun went down, and I've been told off one too many times by the neighbors about firing the bike up in the middle of the night, so I'll post my findings first thing in the morning. Preesh

Evilchicken0
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Re: Won't rev past 6k

Post by Evilchicken0 » Thu May 14, 2015 12:38 pm

Iridium plugs.

They're ok but they can foul and then you're buggered. When you renew them just use copper core, I use the twin electrode one.

evoluzione750
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Re: Won't rev past 6k

Post by evoluzione750 » Sun May 17, 2015 6:54 am

I hope I haven't fouled the new ones yet. :/

The damn thing won't even run now. It'll just barely catch if I try using the starter (choke makes no difference), so I tried bump starting and it felt and sounded like it was only running on two cylinders. Knowing anymore testing would be in vain until I sorted the new problem out, I pulled it back in, and the inside two headers felt cooler than the outer two. The battery defo can't hold a charge and is gonna get replaced, but I'm gonna try the R6 regulator swap that I've read about. The one in it is the old, black epoxy top with the four pin connector that I've read goes bad early and often. There is a random ground wire sticking out of the loom with the other 3 white and 1 red wire going to the regulator, so I thought I could splice in a connector for a ground in order to use the R6 regulator. While I'm at it, I'll have the stator rebuilt. There's a shop down the road that does Ferrari Challenge alternators (my father's good friends with them because they're good ol' boys and I guess they find his English accent amusing), so I doubt they should have trouble with mine. Hopefully that will eliminate any unknowns with the charging system.

As you guys have told me, 90's and 92.5's for the main jets, and I've consulted a parts manual that gives the starter and pilot jets as 52.5 and 35, respectively. The starter jets in the bike are all correct, but I'll replace the mains and pilots (they would be destroyed in the process of extracting to see the number because they're torqued in so tight). That would get me back to stock, and leave just fuel level and clip levels to play with to get it right.

Thanks for the help guys. Sorry if this thing is starting to sound like a basket case. I'm not giving up on it yet!

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Re: Won't rev past 6k

Post by Evilchicken0 » Sun May 17, 2015 8:01 am

Let us know how you on :grin:

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Re: Won't rev past 6k

Post by dobbslc » Sun May 17, 2015 8:35 am

Have you got the O rings installed on the carb tops? These seal the vacuum circuit to the diaphragm's.
Check the sliders are all moving up and down together when you rev it.
Check the washers and O rings on the idle screws are all ok.
There is a strange shaped seal under the jet holder, check that they are all in place and in good condition, it'll run rich if they are knackered.

Dobbs

evoluzione750
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Re: Won't rev past 6k

Post by evoluzione750 » Mon May 18, 2015 4:42 am

The o-rings are all there, but the ones under the top of the carb and mixture screws look a bit worse for wear. The ones under the jet holders look alright. I've ordered a new seal kit so I can replace all of them.

All the slides move freely when revving, but #2 cylinder lags a bit. I think a balance would help.

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Re: Won't rev past 6k

Post by Evilchicken0 » Mon May 18, 2015 11:58 am

The fzr engines don't like unbalanced carbs but it shouldn't affect it to this degree

evoluzione750
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Re: Won't rev past 6k

Post by evoluzione750 » Tue Aug 18, 2015 8:55 pm

With a break in school, I've been able to put a bit of time into the bike.

I've installed a new R6 reg/rec and soldered in the new wires and connections and checked all continuity with no breaks that I can find. I sent the stator to be rebuilt and I've been told the stator off the bike is a 15 pole stator instead of an 18 pole (this might have been immediately obvious to a seasoned grease monkey, but this is my first foray into electrics). I assume that the FZR uses an 18 pole or if a 1WG stator will fit a 3EN1?

As far as sourcing a replacement, would a used OEM off eBay be the best route? Or has anybody tried Caltric replacement electrics? I searched the part number for the stator found in the 1WG parts manual and it popped up.

http://www.caltric.com/yamaha-fzr400-w-1989-stator.html

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Re: Won't rev past 6k

Post by Evilchicken0 » Tue Aug 18, 2015 9:08 pm

I'd use a second hand one off the bay

evoluzione750
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Re: Won't rev past 6k

Post by evoluzione750 » Thu Aug 20, 2015 9:50 pm

I nabbed one off eBay, should be here this weekend.


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