Honda Shadow Forums banner
1 - 12 of 12 Posts

·
Registered
Joined
·
15 Posts
Discussion Starter · #1 ·
So, my bike has sat for a while, and it was hard to start/keep running. Very hard vibration in the bike. It would idle rough, and when I gave it gas, the bike would just die. I pulled the carbs off, gave them a deep cleaning and set them in boiling water to get every thing out that I could. I put the carbs back on, and...no change.

Here's what I've done, and what I've found.

Front cylinder is fine, exhaust gets warm, pull a plug wire, engine runs worse.

Rear cylinder doesn't fire. Exhaust stays cold, pull out the plugs and they're both wet. I test them against the bike frame, and I've got spark to both. I've switched the plugs between cylinders, no change.

So, did I not clean the carbs good enough? Or am I doing something else wrong? Honestly, I'd hate to pull these carbs off again, they were a PITA the first go round, but I'll take any and all suggestion to keep this thing from going to the shop.
 

·
Registered
Joined
·
354 Posts
Sounds like it's time for a compression check. This goes down to the basic three: fuel, compression and ignition. If you're sure about the ignition being present and strong, plug wet (with fuel?) There's only one more.
 

·
Premium Member
Joined
·
2,129 Posts
So, my bike has sat for a while, and it was hard to start/keep running. Very hard vibration in the bike. It would idle rough, and when I gave it gas, the bike would just die. I pulled the carbs off, gave them a deep cleaning and set them in boiling water to get every thing out that I could. I put the carbs back on, and...no change.

Here's what I've done, and what I've found.

Front cylinder is fine, exhaust gets warm, pull a plug wire, engine runs worse.

Rear cylinder doesn't fire. Exhaust stays cold, pull out the plugs and they're both wet. I test them against the bike frame, and I've got spark to both. I've switched the plugs between cylinders, no change.

So, did I not clean the carbs good enough? Or am I doing something else wrong? Honestly, I'd hate to pull these carbs off again, they were a PITA the first go round, but I'll take any and all suggestion to keep this thing from going to the shop.
My guess is you still have carb problems since all you did was to try to clean them. Sounds like you're flooding the rear cylinder, hence the wet plugs. Cause would be a worn float needle valve, bad float or incorrect float setting. If you feel capable of carb rebuilding then invest in a shop manual and carb rebuild kits. Might as well do both at the same time. If not then take your bike to a reputable dealer for the carb service and adjustments.
 

·
Registered
Joined
·
15 Posts
Discussion Starter · #5 ·
I did the carb K&L rebuild kit 18-9348. I saw online where some people suggested running copper wire through one of the jet to clean it out, which I didn't do. I swear. I used 2 bottles of carb cleaner on these carbs, and then sat it in boiling water. Was that not enough you think?

I'd hate for it to be a compression issue...
 

·
Registered
Joined
·
15 Posts
Discussion Starter · #6 ·
Anyone have instructions on how to check the compression? I bought the compression test kit from harbor freight, but I've never done it before.
 

·
Premium Member
Joined
·
7,678 Posts
Anyone have instructions on how to check the compression? I bought the compression test kit from harbor freight, but I've never done it before.
If you've had the bike running, albeit badly, I doubt you have a compression issue. I'd concentrate on the carb for that cylinder. Spark or not, your not going to fire a flooding cylinder. Recheck your float setting, and make sure you don't have a bad needle or seat. Also smell your oil to make sure you're not washing the cylinder wall and putting fuel in the crankcase. Your bearings won't like that very much.
 

·
Premium Member
Joined
·
2,129 Posts
Anyone have instructions on how to check the compression? I bought the compression test kit from harbor freight, but I've never done it before.
Stay on course with your carb issue as I've stated before and backed up by smilie. I ask you again, did you replace the needle valve and seat and check your float setting? If not either one or both will cause engine flooding to that cylinder. Keep it simple before you create more problems.
 

·
Registered
Joined
·
15 Posts
Discussion Starter · #9 · (Edited)
Stay on course with your carb issue as I've stated before and backed up by smilie. I ask you again, did you replace the needle valve and seat and check your float setting? If not either one or both will cause engine flooding to that cylinder. Keep it simple before you create more problems.
I replaced them both. How do I check my float setting?

Here's the kit I used:
http://www.ebay.com/itm/NEW-HONDA-CARBURETOR-REPAIR-KIT-VT750-VT-750-SHADOW-1998-2003-/121298285184

It didn't come with new filters.
 

·
Registered
Joined
·
15 Posts
Discussion Starter · #11 ·
Can someone tell me where the small air tube that comes off the top of the carbs goes? It fell off when I was removing the carbs.

It's the ones on page 5-9 of the manual at the very top. I can't find where it's supposed to lead to...
 

·
Premium Member
Joined
·
7,678 Posts
Unsure of your particular bike, but probably a pair control vacuum hose. Two come off the carb and go into a tee and then on to the pair control valve.( on my '07) If you have an oem manual, it will show diagrams identifying all your hoses.
 
1 - 12 of 12 Posts
Top