Instant red lining in neutral

A place for LC enthusiasts to hang out!

Moderators: rztom, 2smoke

Message
Author
LC Cnd
-----
-----
Posts: 1454
Joined: Sat Feb 08, 2014 5:39 pm
Location: Vancouver Is. Canada

Instant red lining in neutral

#1 Post by LC Cnd » Fri Jun 10, 2016 8:53 pm

Fired up my Elsie last weekend using a sorta IV line(s) fm a stainless steel mini gas tank for full. Stunningly it fired up frist kick and back her down to a 1200-1300 idle. Placed the tank on and the fuel cock leaked gas. Discovered the spring, inside the fuel selection switch, was gone - fixed. Fired her up again, on reserve tank ,and the engine immediately rev'd to 9000. Shut her off with the kill switch. It did it again and both times the throttle was not even pulled on. Sticky carb slide perhaps? Suggestions?

chalpkin
Posts: 12
Joined: Wed Apr 08, 2015 9:28 am

Re: Instant red lining in neutral

#2 Post by chalpkin » Fri Jun 10, 2016 9:01 pm

Sounds like an air leak of sorts to me!

Sent from my SM-G800F using Tapatalk

tacky1
Posts: 950
Joined: Wed May 13, 2015 1:11 am
Location: Pacifica,,

Re: Instant red lining in neutral

#3 Post by tacky1 » Fri Jun 10, 2016 9:02 pm

Maybe the tank snagged the throttle cable when you were refitting it, Remove the tank and fire it up and see if it does it then
1985 RZv500
1984 RZ500 Hybrid
1986 RG500 Walter Wolf
1986 RG500 Skoal Bandit
1984 RZ350
1984 RZ350 Hybrid
1981 RD350LC
1981 RD350LC Hybrid
2009 CR500AF Supermoto 250X
2007 CR500AF 250X
1988 YSR50 (2)
1984 GPZ750 Turbo
1989 VFR750R RC30

LC Cnd
-----
-----
Posts: 1454
Joined: Sat Feb 08, 2014 5:39 pm
Location: Vancouver Is. Canada

Re: Instant red lining in neutral

#4 Post by LC Cnd » Sat Jun 11, 2016 1:22 am

Pulled off the tank to examine the carbs. The throttle collection and carb cables all function freely. Ck'd the carb slides - left moved slick up and down, the right appeared stuck. Removed that slide. It had no residue or anything that would make it lodge. Placed it back in and oddly could not connect the guide tab with the groove found on the slide(?). However at one point the slide popped in but the groove was nowhere near where the guide is located (photo attached). Do these guides wear? Do aftermark carb replacement kits simply not alway match the carbs? Hmm... Has anyone purchased new guides to replace those that appear worn - that's what appears to be the issue. Thx
Attachments
IMG_3207.JPG
IMG_3207.JPG (52.43 KiB) Viewed 5824 times

User avatar
South_Oz
-----
-----
Posts: 529
Joined: Sun Jul 22, 2012 8:29 am
Location: South Oz

Re: Instant red lining in neutral

#5 Post by South_Oz » Sat Jun 11, 2016 2:06 am

I have moved a guide to the other side. Easy enough to do, carefully drill out the (3?) small punch marks that hold the guide in and remove. I was lucky in that I had drilled a hole opposite the guide to refit it so just used a punch to tap it out. I would try a screw driver handle maybe to push it out?

Dave
RZ 250 85 (Waiting)
RZ 250 85 (Parts)
RGV VJ21 250, Australian Speed Record Holder, MPS/G 250, 140.5 MPH
BMW R1100S 99 (Its Red)
BMW R1200GS (Its BIG)


http://www.dlra.org.au/index.htm" onclick="window.open(this.href);return false;

LC Cnd
-----
-----
Posts: 1454
Joined: Sat Feb 08, 2014 5:39 pm
Location: Vancouver Is. Canada

Re: Instant red lining in neutral

#6 Post by LC Cnd » Sat Jun 11, 2016 2:20 pm

I thought one could just adjust the guide by a clockwise twist using the exterior slot using a screwdriver or give it a tap fwd?
Attachments
IMG_3210.JPG
IMG_3210.JPG (135.77 KiB) Viewed 5791 times

LC Cnd
-----
-----
Posts: 1454
Joined: Sat Feb 08, 2014 5:39 pm
Location: Vancouver Is. Canada

Re: Instant red lining in neutral

#7 Post by LC Cnd » Sat Jun 11, 2016 10:05 pm

Ck'ing the slide I noted 2 burrs on the bottom end - suspect that is what the slide hung up on. Possibly damage by an accidental drop. Good thing I discovered this b4 it occurred on the road - an MVA avoided. Replaced with another slide and the carb worked perfect. No need to replace the guide. Might file off the burrs to save the slide.
Attachments
IMG_3228.JPG
IMG_3228.JPG (65.39 KiB) Viewed 5770 times

Bare
Posts: 1196
Joined: Sun Jan 29, 2006 2:18 am
Location: vancouver

Re: Instant red lining in neutral

#8 Post by Bare » Sun Jun 12, 2016 5:24 pm

Note that these aged Mikunis develop a Nasty habit of Sticky Slides after a season's use.
Requiring a Good carb strip down to 'fix' for the next season.

LC Cnd
-----
-----
Posts: 1454
Joined: Sat Feb 08, 2014 5:39 pm
Location: Vancouver Is. Canada

Re: Instant red lining in neutral

#9 Post by LC Cnd » Sun Jun 12, 2016 11:56 pm

I actually sonic cleaned them both and used carb cleaner on the bowl n' floats. I spoke too soon - now it rev's to 8000. Cables run free. Just don't get it - idle screw perhaps. Mysterious. Any other suggestions?

John
Posts: 30
Joined: Thu Dec 10, 2015 12:27 pm
Location: Cumberland, BC, Canada

Re: Instant red lining in neutral

#10 Post by John » Mon Jun 13, 2016 3:49 am

Have the float bowls been swapped side to side?
Also check the choke tube between the carbs.

chalpkin
Posts: 12
Joined: Wed Apr 08, 2015 9:28 am

Re: Instant red lining in neutral

#11 Post by chalpkin » Mon Jun 13, 2016 4:49 am

LC Cnd wrote:I actually sonic cleaned them both and used carb cleaner on the bowl n' floats. I spoke too soon - now it rev's to 8000. Cables run free. Just don't get it - idle screw perhaps. Mysterious. Any other suggestions?
Like I said earlier, it sounds like an air leak!

Sent from my SM-G800F using Tapatalk

LC Cnd
-----
-----
Posts: 1454
Joined: Sat Feb 08, 2014 5:39 pm
Location: Vancouver Is. Canada

Re: Instant red lining in neutral

#12 Post by LC Cnd » Mon Jun 13, 2016 8:57 pm

Odd an air leak did no appear during the external tank usage. Time for a leak down test perhaps.

Hooligan
Posts: 1966
Joined: Mon Aug 20, 2012 1:37 am
Location: Calgary, Alberta

Re: Instant red lining in neutral

#13 Post by Hooligan » Tue Jun 14, 2016 2:02 am

John wrote:Have the float bowls been swapped side to side?
Also check the choke tube between the carbs.
They won't run for sh!t with this tube missing.
'82 RD350LC in '81 colours, OEM pipes, UNI filters
'85 FZ750

Hooligan
Posts: 1966
Joined: Mon Aug 20, 2012 1:37 am
Location: Calgary, Alberta

Re: Instant red lining in neutral

#14 Post by Hooligan » Tue Jun 14, 2016 2:05 am

LC Cnd wrote:Pulled off the tank to examine the carbs. The throttle collection and carb cables all function freely. Ck'd the carb slides - left moved slick up and down, the right appeared stuck. Removed that slide. It had no residue or anything that would make it lodge. Placed it back in and oddly could not connect the guide tab with the groove found on the slide(?). However at one point the slide popped in but the groove was nowhere near where the guide is located (photo attached). Do these guides wear? Do aftermark carb replacement kits simply not alway match the carbs? Hmm... Has anyone purchased new guides to replace those that appear worn - that's what appears to be the issue. Thx
The problem here was not that the slide groove would not find the tab but that the needle was hung up on the top lip of the needle jet. Happens to me all the time with my RZ. Total PIA to get the slides back into the carbs.

I'd pull the carbs, remove the slides from the cables and check by hand to see how the slides move freely (or not) inside the carb body.
'82 RD350LC in '81 colours, OEM pipes, UNI filters
'85 FZ750

Hooligan
Posts: 1966
Joined: Mon Aug 20, 2012 1:37 am
Location: Calgary, Alberta

Re: Instant red lining in neutral

#15 Post by Hooligan » Tue Jun 14, 2016 2:06 am

LC Cnd wrote:Odd an air leak did no appear during the external tank usage. Time for a leak down test perhaps.
Not really. If the thing hasn't run for a while, the reed block gasket can dry out. Save yourself the time, just replace the reed block gasket and use some grey moto-seal on the carb rubbers etc. Saves a lot of hassle and won't leak over time.
'82 RD350LC in '81 colours, OEM pipes, UNI filters
'85 FZ750

Post Reply