Recent Topics
Cold start tick...
by Doublehaul
Yesterday at 11:20 PM
Leaving Fayetteville, North Carolina
by NJC
Yesterday at 10:37 PM
Is Old Coolant better or worse than water?
by Ducked
Yesterday at 10:35 PM
DIY Transmission Flush or Drain and Fill
by Rochev
Yesterday at 10:23 PM
replaced the Sentra cabin filter 2.5 years 32k m
by tomcat27
Yesterday at 09:56 PM
Would you use 4 1/2 year old Mobil 1 ?
by sHERM
Yesterday at 09:49 PM
mystery rattle in 2015 Rogue - solved
by tomcat27
Yesterday at 09:48 PM
John Deere X500, X530
by HM12460
Yesterday at 09:41 PM
buying oil in bulk vs when needed to keep records
by motor_oil_madman
Yesterday at 09:36 PM
DON'T let this be YOU....slow down.
by SumpChump
Yesterday at 09:30 PM
Body Filler Substitute
by Ducked
Yesterday at 09:24 PM
2003 5.3 oil pressure sender
by spasm3
Yesterday at 09:11 PM
Newest Members
nyquil_junkie, BlackThumb, Roswellien, Luis_Gabriel, Tech_man123
59772 Registered Users
Who's Online
21 registered (4WD, billt460, edhackett, Farmer, 3 invisible), 813 Guests and 14 Spiders online.
Key: Admin, Global Mod, Mod
Forum Stats
59772 Members
66 Forums
257815 Topics
4240932 Posts

Max Online: 2862 @ 07/07/14 03:10 PM
Donate to BITOG
Topic Options
#2271892 - 05/26/11 09:59 PM Cylinder not firing? 2002 Honda Shadow 750
kevinf Offline


Registered: 05/08/09
Posts: 137
Loc: Virginia
I'm trying to get a motorcycle back in service. I've cleaned the carb jets once already. The front cylinder appears to not be firing based on the amount of heat I feel in the exhaust pipe(hmmmm),compared to what's coming out the rear exhaust pipe (yeeeouch!). I switched the coils, front to back, and it ran the same way. I checked the float bowl in the front carb, and it had fuel in it. What are the next steps I should take to diagnose the problem?
_________________________
---
'07 Toyota Sienna - Castrol GTX 5W30
'01 Toyota Sienna - PP 5W30
'98 Acura CL 3.0 - G-Oil 5W30

Top
#2271896 - 05/26/11 10:12 PM Re: Cylinder not firing? 2002 Honda Shadow 750 [Re: kevinf]
Chris142 Offline


Registered: 06/05/03
Posts: 14491
Loc: apple valley, ca
Did you actully ck for spark?
_________________________
02 Wrangler Chevron 10w30
87 F250 napa 15w40
04 Tahoe super-s 5w30
Z400 Lucas 10w30
KLR250 Maxima 10w40
Can am maveric edge 5w40

Top
#2271950 - 05/26/11 11:26 PM Re: Cylinder not firing? 2002 Honda Shadow 750 [Re: Chris142]
kevinf Offline


Registered: 05/08/09
Posts: 137
Loc: Virginia
No, how do I do that safely? I was going to buy an extra plug and tape it to the cylinder head so that it's grounded.
_________________________
---
'07 Toyota Sienna - Castrol GTX 5W30
'01 Toyota Sienna - PP 5W30
'98 Acura CL 3.0 - G-Oil 5W30

Top
#2272047 - 05/27/11 07:07 AM Re: Cylinder not firing? 2002 Honda Shadow 750 [Re: kevinf]
Trav Offline


Registered: 11/20/06
Posts: 14601
Loc: MA, Mittelfranken.de
Did you try a new plug?
_________________________
ASE L1, Master. Deutsch Meisterbrief.

Top
#2272095 - 05/27/11 08:22 AM Re: Cylinder not firing? 2002 Honda Shadow 750 [Re: kevinf]
meep Offline


Registered: 02/20/07
Posts: 3033
Loc: Southeast
you need, spark, fuel, and compression.

pull the plug, tape, lay, tie, it to something and crank. look for spark.

sniff the tailpipe for fuel. don't stick your nose in it, use your hand to waft the fumes towards you. you can also try a squirt of starter fluid.

I love the older shadows. first bike I ever rode was a 500 shaft drive, a wonderful, wonderful machine.
_________________________
2006 Tundra 2wd
2015 crv (wifey!)
2005 s60 2.4L

Top
#2272183 - 05/27/11 09:55 AM Re: Cylinder not firing? 2002 Honda Shadow 750 [Re: kevinf]
Bladecutter Offline


Registered: 02/21/11
Posts: 1341
Loc: Dacono, CO
Did you pull the pilot jets, and run a copper strand through it to make sure they weren't plugged?

Have you pulled the non-firing spark plugs to see if they are fouled or dry? Switch the plugs between the two cylinders. Should be a 2 plug per cylinder setup for the Honda 52 degree V-Twin.

Here's what I would do if it were my bike, in order:

Pull carbs, and recheck the pilot jets for clogs, and reset the mixture screws to 2.5 turns out. Might be worth the $20 to replace both pilot jets with new ones.

Check the spark plugs for fouled or dry condition.
Replace if fouled.

Check valve clearances (too tight valves lead to idle issues).

I work on lots of motorcycles, and see your symptoms on a regular basis every spring. Chances are your bike sat over the winter. New (or properly cleaned) pilot jets should get you up and running right quick.

BC.
_________________________
2014 Mazda CX-5 Touring (Soul Red)
2015 Porsche Cayman
2007 Ducati 848
1988 Honda Hawk GT

Top
#2272229 - 05/27/11 10:37 AM Re: Cylinder not firing? 2002 Honda Shadow 750 [Re: kevinf]
mechtech2 Offline


Registered: 09/05/06
Posts: 19479
Loc: Chicago Area
I'm with Blade.
It's probably fuel related. There are all sorts of jets and passages besides the main jet. Amateurs concentrate on the main only.
Fresh plugs Are always smart in a scooter, esp after misfiring for whatever reason.

Top
#2272347 - 05/27/11 12:02 PM Re: Cylinder not firing? 2002 Honda Shadow 750 [Re: kevinf]
dwendt44 Offline


Registered: 05/17/06
Posts: 3605
Loc: Central Wisconsin
Ya, the carb is still plugged.

Resurrected an old Suzuki twin. First time I cleaned the carbs, it would only run on one cylinder. Cleaned them again(they are bracketed together) with a stronger carb cleaner. Then it ran fine.
_________________________
There's no such thing as:
Too big of a battery,
Too large of a gas tank,
or too loud of a horn,
or too bright headlights.

Top
#2272372 - 05/27/11 12:37 PM Re: Cylinder not firing? 2002 Honda Shadow 750 [Re: dwendt44]
kevinf Offline


Registered: 05/08/09
Posts: 137
Loc: Virginia
Thanks for the input so far. I bought two new plugs for that cylinder, now I'll check spark to rule that problem out definitively.

Based on the response posts, now I'm thinking that I didn't get that front carb clean enough. It was the first one I worked on and I may have been too careful with it and not clean agressively enough. It is a real pita to get those joined carbs off and on in that teeny space. I think I'll video record how I remove them this time so I can get them back on easier.

I have a compression tester for my car. Do they sell adapters for it to work on a motorcycle, the spark plug is narrower, no?
_________________________
---
'07 Toyota Sienna - Castrol GTX 5W30
'01 Toyota Sienna - PP 5W30
'98 Acura CL 3.0 - G-Oil 5W30

Top
#2272585 - 05/27/11 05:25 PM Re: Cylinder not firing? 2002 Honda Shadow 750 [Re: kevinf]
Bladecutter Offline


Registered: 02/21/11
Posts: 1341
Loc: Dacono, CO
Yes, compression testers have adapters to work on the smaller spark plug holes. The kit I bought many years ago came with several fittings, one of which works with just about every motorcycle I've ever used it on.

A tip for narrow angle v engines is to remove one intake boot with the carbs, while leaving the second one still attached with the engine. Makes life much, much easier. Just be grateful you aren't doing the carbs on a Honda Interceptor with the V-4 engine. That's a royal pain in the bum getting them on and off.

Make sure when you remove the carbs from the bike, and are working on cleaning them, that you unscrew the pilot jets (#40 size for your bike), and hold them up to the light to see through them. If you can't see through it, its clogged. You should see light coming through.

BC.
_________________________
2014 Mazda CX-5 Touring (Soul Red)
2015 Porsche Cayman
2007 Ducati 848
1988 Honda Hawk GT

Top
#2272686 - 05/27/11 08:12 PM Re: Cylinder not firing? 2002 Honda Shadow 750 [Re: Bladecutter]
kevinf Offline


Registered: 05/08/09
Posts: 137
Loc: Virginia
Thanks everyone - update

OK, it has spark, and now it has two new plugs in the front cylinder.

I'll pull the carbs again when I get time.

Here's something I thought was bizarre, I called Actron and they were out of 12mm adapters for their compression testers. Part is 0180-000-0894. How does a manufacturer run out of a simple component they sell on a regular basis? I may buy a cheap compression tester kit from Harbor Freight just to get the adapters.
_________________________
---
'07 Toyota Sienna - Castrol GTX 5W30
'01 Toyota Sienna - PP 5W30
'98 Acura CL 3.0 - G-Oil 5W30

Top
#2273226 - 05/28/11 01:33 PM Re: Cylinder not firing? 2002 Honda Shadow 750 [Re: kevinf]
mechtech2 Offline


Registered: 09/05/06
Posts: 19479
Loc: Chicago Area
If it ran OK before it was stored, the engine probably is did not break mechanically when sitting.

It's the carb[s].

Top