Kawasaki VN750 Forum banner

1 - 16 of 16 Posts

·
Registered
Joined
·
10 Posts
Discussion Starter #1
Greetings!

Two things: 1) I've recently developed a backfire even at start-up. One guy suggested racing fuel to clean out the system. What do you guys think?

2) I can't get a standard plug socket from Sears on my spark plugs. Do I need a special spark plug socket to do the change myself? My bike is a '94.

I'm not much of a mechanic, but a couple years ago some of you pointed me to a solution that was right on the money for my cycle. I'm hoping you can help again.

Thanks either way.

Daryl
 

·
Old Truck Junkie
Joined
·
4,133 Posts
You need a thin walled socket. I had to grind one down to fit. I would not go with racing fuel. I would go with sea foam or some other product made for carb cleaning while riding.
 

·
Premium Member
Joined
·
4,778 Posts
X2 on Sea Foam!
 

·
Sparky!!!
Joined
·
8,697 Posts
backfire at startup is caused by one of three things... either a problem with the ignition system, a vacuum problem, or a carb problem, or it could be a combination of them all. I personally would start with the easiest and cheapest to fix which would be vacuum leaks around the carb boots, and the carb vacuum ports, from there I would get into the ignition system... make sure both cylinders are firing on all four plugs. usually with the plugs not firing it is as simple as a plug on one of the coils came loose, or the pickup coil assembly is grounding out. Both are easy and cheap (if not free) to fix.
 

·
Registered
Joined
·
10 Posts
Discussion Starter #5
Thanks for the help. I'll try to get a thin walled socket and change the plugs, since I wanted to do that anyway, then check the other items mentioned. I have sea foam in the tank now, awaiting a little warmer weather to ride. We had some snow last night. I appreciate all your comments.
 

·
Heading to the DARKSIDE!
Joined
·
177 Posts
Make an investment for the best and get 4 NGK Iridium spark plugs. (DPR7-EIX...I think that is the model#) Much easier starting of the bike....and better spark combustion. They are worth more to the bike reliability then you will pay for them. Almost everyone on here will recommend this upgrade. Also when it comes to battery replacement go with a NON- Chinese made AGM Maintenance free battery. That style of battery is also worth way more than the little extra money that you will pay for it.:smiley_th
 

·
Registered
Joined
·
140 Posts
You need a thin walled socket. I had to grind one down to fit. I would not go with racing fuel. I would go with sea foam or some other product made for carb cleaning while riding.
Actually, it's an 18mm deep metric socket. Works great!!
 

·
Registered
Joined
·
140 Posts
Yup. Those would be the ones;-) Got mine @ Auto Zone. I had the same prob. 20G's in tools and I didn't have a plug socket that would fit. Till then!
 

·
Registered
Joined
·
399 Posts
Before i replace my battery, i would occaisionally get a backfire when trying to start. all is fixed now, but my question is, does a backfire cause any damage? I know on my boat, with a Holly 4160, a backfire requires the replacement of the powervalve. anything like that on the bike?
 

·
Concert connoisseur
Joined
·
2,231 Posts
craftsman part # 44435 3/8 drive 18mm deepwell
 

·
Super Moderator
Joined
·
11,934 Posts
Before i replace my battery, i would occaisionally get a backfire when trying to start. all is fixed now, but my question is, does a backfire cause any damage? I know on my boat, with a Holly 4160, a backfire requires the replacement of the powervalve. anything like that on the bike?
I'd have to say a backfire on the Vulcan...is not going to hurt the bike. A backfire is just fuel igniting in the exhaust...so as long as no seals got blown out , there should be no repair issues.

KM
 

·
Registered
Joined
·
3 Posts
I occasionally get one backfire at start up, but I blame it on accidently twisting the throttle as I back the bike out of my garage before starting it. Could be wrong...
 

·
Prowling Tiger
Joined
·
2,048 Posts
Still has to be thin walled as NR said... a standard US made 18mm deep well socket is too thick... now the cheap Chinese 18mm sockets are thin walled.
I beg to differ! I used my Craftsman 18mm and had no problems getting the plugs out. Maybe el-cheapo brands are thicker. Dunno.
 

·
1986 VN750
Joined
·
3,255 Posts
I beg to differ! I used my Craftsman 18mm and had no problems getting the plugs out. Maybe el-cheapo brands are thicker. Dunno.
I use standard Husky deep sockets and have had no problem. My Metwrench sockets also fit.
 
1 - 16 of 16 Posts
Top