Rough idle, hard start, lots of popping

[1327NYVMAX]

Bike: 1992 PCW 1327cc chain drive with about 1000 miles on the motor

So I just got my bike back from my mechanic. He took the carbs off and cleaned them, replaced the plugs and tuned and synced the carbs.

The bike ran well at his shop when I picked it up, I brought it home, put all the other pieces (Scoops, seats, etc...) back on and went to take it for a test ride. The bike was very hard to start and will not start with the choke on. When it does start it jumps up to about 3000 rpm then drops and stalls. To keep it running long enough to warm up I have to hold the throttle at about 2000 then out of no where the bike will jump to 4000 or higher with no touch of the throttle. Once the bike gets a little temp in her she will idle ok for about 15-20 seconds then the idle will jump up to about 4-5k without touching anything on the bike. It smells like it is running really rich, lots of popping and backfiring and a little smoke.

I am really bad with carbs and know almost nothing about them, I am not even sure if they are the problem...

Any help on what could be going wrong would be awesome.

btw, the guy who did the carbs has done mine before and has always done a great job.

thanks,
Jake

 

[dannymax]

Does it have oem carbs or flatslides?

Was it running good when you brought it to the shop?

If yes to the above I think I'd try the shotgun a time or two before going any further. See if you get any change in symptoms with that.

 

[1327NYVMAX]

The bike was not running when I brought it into the shop, the bike hadn't been run in about 10 months. I inherited the bike from my father after he put it into a guardrail at about 25 mph. I slowly aquired all the parts and got it back together. I ran it about 100 miles last summer then it sat while I had some other things going on. When I went to start it this year I got nothing and decided I would have the carbs cleaned, new plugs and airfilter. After that it has been down hill.

 

[dannymax]

The bike was not running when I brought it into the shop, the bike hadn't been run in about 10 months. I inherited the bike from my father after he put it into a guardrail at about 25 mph. I slowly aquired all the parts and got it back together. I ran it about 100 miles last summer then it sat while I had some other things going on. When I went to start it this year I got nothing and decided I would have the carbs cleaned, new plugs and airfilter. After that it has been down hill.

I remember your post from back in '08...hope your Dad is doing well.

Just thinking as a starting point, the shotgun would be worthwhile....may do nothing but it's cheap and non-invasive.

 

[1327NYVMAX]

I am going to try that tonight to see if it helps at all.

the real concerning part for me is the idle jumping up on it's own.

 

[4gasem]

Any rust in the tank?

Hard to tell but he could have knocked some crap loose which found it's way into something it shouldn't have. I wonder if he disassembled the jet blocks and cleaned it out. (probably not) and does it have ethanol in it? DO NOT use ethanol in it, if it has stock carbs.

Chris

 

[1327NYVMAX]

Carbs are stock, no ethanol... going to try the shotgun cleaning then see where it goes from there.

 

[COP RUNNER]

Did You Ride The Bike Home From The Mechanic ., Or Trailer It ?

 

[1327NYVMAX]

back of my truck...

 

[4gasem]

Carbs are stock, no ethanol... going to try the shotgun cleaning then see where it goes from there.

Bet there's poop in the jet block.

 

[1327NYVMAX]

I am hoping it is that simple.

 

[4gasem]

These bikes are VERY simple... Make sure if he replaced parts that he didn't use non oem parts in the carb. ONLY oem parts should be used.

 

[1327NYVMAX]

He used all OEM parts on the bike, I have learned that is the only way to go when you have the opportunity.

 

[Rhoy Carter]

My question is where to get gas without ethenol? All the gas within 200 miles of Houston has ethenol. My 85 runs fine on it but I do make sure that i ride it at leaste 30 minutes every week to keep from having carb problems.

 

[dannymax]

My question is where to get gas without ethenol? All the gas within 200 miles of Houston has ethenol. My 85 runs fine on it but I do make sure that i ride it at leaste 30 minutes every week to keep from having carb problems.

Yeah, same here. Only place I could think of was the local airport, but could nver find anyone there to see about getting any. Think that was 100 octane too, but not sure....Tugla would know.

 

[tugla]

100LL is not rated the same way as mogas or car pump gas. octane is 100 but for a plane, eg 2500rpm and various altitudes. what it does have is lead which most of us know from the old days is way better in helping flame travel in the combustion chamber, helps fully burn all the fuel. notice the 60's and 70's your pipes where white not black.
So adding very little, usually just grams of it to any mogas will raise the octane of the fuel. dont need octane in our vmax's so dont want to go too high, but sure does smell way better then reg fuel, nice sweet smell of avgas unk: been running the hotrod on it for long time, not soo much in the bike, its a very dry fuel and can end up burning valves pretty fast. it does last up to 6 months so way better then reg fuel which breaks down pretty much when it leaves a refinery. So i wouldnt recommend running it all the time in your bike, but a 1/2 gal wont hurt ya, better then ethanol. also great for cleaning parts and it evaporates real fast so if you get it on your hands wont be there long.

oh ya did i mention it smells wicked when running the stuff unk:

oh ya jetting a little different with ethanol.

 

[Buster Hymen]

My question is where to get gas without ethenol? All the gas within 200 miles of Houston has ethenol. My 85 runs fine on it but I do make sure that i ride it at leaste 30 minutes every week to keep from having carb problems.

Here in Ontario, the Shell gas stations don't (or claim they don't) have ethanol in it if you buy the premium gas.

 

[tugla]

at least you still have sunoco, they pulled out of que, actually ultramar bought them, but miss sunoco gold, thats good fuel.
got a specific gravity tester kit we use for racing, since every batch can be different and with pressure chg, so can find exact jet chg needed to keep max performance once you got a set-up. not worth the time on a reg bike but if you were racing makes a diff on performance for sure to stay consistent, and see if you got a crap batch of fuel.