Engine drivability, cold and part throttle

[firea100]

Hi to all on the site! Just bought a real nice 1999 Standard from Jeff Smith and his Wife, Tammy. Found it on this site! Now that the bike is up here in cold Michigan, I find that it is VERY cold blooded, it is hard to drive when it is cold even with the choke applied and seems to have a little stumble at part throttle if you hold the throttle steady even when warm. If you open it up a little it seems to go away. I'm comparing this to my 1995 Aspencade which seemed to have a very smooth acceleration. Where do we start? Carb sync.- Choke adj.- or what? The bike has only 17.5K on it. Is there anyone in Southeast Mi. that is reputable in doing a sync. on my bike? Thanks, Larry Gill in East China Mi.

[9Ball]

others will pipe in, but based on the limited info you gave you might not be engaging the enricheners fully (push the lever past the first stop) and you could have plugged slow jets.

Seafoam may be your friend, if not then cleaning the carbs and replacing the jets may be in your future.

Do a search...lots have been through the same.

[R J]

Seafoam

Choke ALL THE WAY on.
When ya hit resistance, push it some more.
When the RPM's come up, back off the choke...

Take it out and run the snot out of it for about 10 miles.

Sounds like it is carboned up.

If all of the above fails.

DESMOG it..........

[asfltdncr]

The choke does take more movement than one might think-all the way down.
Also, it never hurts to add some Seafoam or Techron fuel additive in case your jets might be a little fouled.And...make sure that when you winterize to add something to stabilize your fuel.I believe the aforementioned are also stabilizers.

[PhredValk]

How much Sea Foam? I used it for a few days before an oil change and it cleand all the gunk out nicely (talking about my old GL1100, the Valk is new) but I tried it in the fuel once and the bike ran like crap for 3 tanks of gas. I thought it ate the seals or something, but it got better eventually.
Everything I read about Foam looks good, but I'm a little shy about using it in fuel...
Fred.

[roboto65]

Do not be shy about using Seafoam in your fuel ALOT and I mean ALOT of us have been using it for a while and it works great heck a strong dose is half the can for me well for my IS since it is almost 7 gals but it will not harm anything to add it only help. 

[Foozle]

I am facing a very similar situation with my 1998 Standard.  With the choke fully engaged, it starts fine - but takes much longer to warm up to a steady idle than is normal.  I'm a faithful Seafoam user, so my next step is to desmog.  If, after a carb sync, the problem still persists - I'm probably looking at some carb maintenance (e.g., replacing the slow jets).  On a ~12 year-old bike with original vacuum hoses, intake o-rings, etc., I'm thinking (hoping!) the desmog will do the trick.  Honestly, I think the best remedy to avoiding these problems is regular use - which, personally, a lack of time has not recently allowed.  Good luck!  Terry

[firea100]

Well today I finally had time to pull my spark plugs and to my surprise there were no fouled plugs. They pretty much looked the same. All were very clean in appearance and don't have any signs of detonation or overheating. I still have the low rpm miss/studder that seems to improve when the rpm increases. I did add a bottle of Techron to a full tank of regular gas and I'm half way through the tank with no change in the symtoms. On the next fill up I may put a bottle of Seafoam into the tank to see if that helps any. I'm beginning to think I may have dirty slow jets. I'll see after the next tank. I'm planning on a 400 mile round trip this weekend so maybe something will break loose in the jets? any info please post or e-mail me with your thoughts. Thanks, Larry Gill in East China Mi.

[John U.]

I tend to agree with your diagnosis. If the slow jets are clogged the Techron will do the job. Unless the clogging is due to rust or debris in the fuel. Large enough bits of junk can get through the petcock screen.
If that's the case it's time for new jets. Some of us change to 38s from the OEM 35s. Capparral or Sudco has them.
Check the tank for rust and consider a fuel filter.
Make sure you don't have vacume leaks. The smog system involves a lot of rubber tubing, which unless it's been changed (or removed) is getting old by now.
Desmog is an option to reduce the possibility of vacume leaks.
Could also be the intake tube O-rings are leaking. Redeye Tech sells them in viton, which holds up better.
Let us know how it works out.
O yeah, tighten up the band clamps that hold the carbs to the intake tubes.

[Rio Wil]

Hi to all on the site! Just bought a real nice 1999 Standard from Jeff Smith and his Wife, Tammy. Found it on this site! Now that the bike is up here in cold Michigan, I find that it is VERY cold blooded, it is hard to drive when it is cold even with the choke applied and seems to have a little stumble at part throttle if you hold the throttle steady even when warm. If you open it up a little it seems to go away. I'm comparing this to my 1995 Aspencade which seemed to have a very smooth acceleration. Where do we start? Carb sync.- Choke adj.- or what? The bike has only 17.5K on it. Is there anyone in Southeast Mi. that is reputable in doing a sync. on my bike? Thanks, Larry Gill in East China Mi.

Larry, if I understand what you are saying.....it ain't broke!  Sounds like the choke is not being engaged fully to start the bike. You have to be a absolute brute pushing on the choke to get it engaged, the first inch of movement does NOTHING, ya gotta push it another 3/4 inch against very difficult resistance to get the enrichers to open.  If the very little stumble is in the 1100-1300 rpm range and goes away above that....it ain't broke there either. So, if this is the case.....just ride the beast and be happy, no additives needed.
I can't remember the last time I had to use the choke to start my bike,  like someone previously mentioned, regular use is the best maintenance. You didn't say it, but I presume the bike runs fine in all other aspects.....good power, accelerates like a scalded ape, makes you smile when you twist the throttle.

[sugerbear]

400 miles??!!! what ya going for lunch?

+1 on the choke

enjoy

[Pete]

+++ on choke use, be sure it is actually pressed far enough.

It is entirely possible that the additives will not clean up the slow speed jets, and you will need to remove the carbs and clean them well.

The slow speed stumble is not normal and may indicate a lean condition, so first clean the carbs and if that does not fix it then open the slow speed jet screws say 1/2 turn.

Adding additives to the fuel will help sometimes. But for a stronger cleaning action, remove the fuel tank drain the carbs and pour straight additive into the carb bowls thru the fuel line and let it set for a while. Then drain the additive and see what it removed.

Nothing works as well as a dis-assembly and cleaning of all carb parts, usually.

[Chrisj CMA]

How much Sea Foam? I used it for a few days before an oil change and it cleand all the gunk out nicely (talking about my old GL1100, the Valk is new) but I tried it in the fuel once and the bike ran like crap for 3 tanks of gas. I thought it ate the seals or something, but it got better eventually.
Everything I read about Foam looks good, but I'm a little shy about using it in fuel...
Fred.

I think seafoam in the OIL is not a good thing......it will act like a solvent and thin the oil too much IMHO.  Techron/ Seafoam in the gas will do more to decarbon the motor.  I put a can of Seafoam through the old gal .....at a half tank I put a half can, then when I filled up after running to reserve I put the other half can in the full tank........so I had double strength then half as strong........now shes running like new again. I too was getting a slight stumble on the low jets and during easy low speed acceleration.  Now, its perfect again.  Seafoam is not going to make this motor run bad.  If it does theres something else going on

[Momz]

Larry,

If you're in East China, then I would recommend you go to "Michigan Chrome Shop" in Richmond MI.

They will diagnose and repair any problems you may have (vacuum leaks, petcock diaphram, failing battery, etc) without charging an arm and a leg. They have supported the S.E. MI VRCC chapter with honesty and integrity.

Good luck and many happy miles.

[Mr.BubblesVRCCDS0008]

On my I/S the choke lever  will go down below the split  in the switch control housing. If your not getting it down that far your not getting full choke.

[firea100]

I have proper choke application (easy to push , then hard to push). the engine reacts like it should with the choke on. What I believe I'm starting to see (hear) is a is a vacuum leak on my Port (left) bank of cylinders. I was at a drawbridge yesterday afternoon and was idling the motor next to a truck that was shut down and could hear what I felt was a vacuum leak on the left side. It had the familular hissing but it seemed to be cycllic or at one time per revolution of the engine. Once it turns light in my part of the country, I'll warm up the bike and try a little Gumout carb spray and see if it reacts to it. The bike seems to run better with a little choke applied, so I'm leaning toward a lean condition (pun intended). I have also had several exhaust backfires on severe deceleration. Not always, just on a decel from a hard acceleration. And then, not all of the time. I've ran a tank of fuel with the Techron and a tank with Sea foam with little to no change. the bike runs hard and fast on the E-way, it's just the cruising in town at 10-25 or 30 mph that the stumbling occurs. Part of the issue is my inexperience with my bike. I've only had it for a month or two and it has just warmed up enough to be able to enjoy it. My only other experience with this is my '95 Aspencade, which was silky smooth on low speed acceleration. I first thought, maybe it's because of a different cam profile and the six carbs. But the more I drive it, the more it becomes evident that something isn't right. I'll try the carb cleaner and report back Thanks for all of the responses, This is a great site. I'm looking forward to meeting with some of the folks in SE Michigan soon. Come on summer!!

[Cleaner Man]

Sometimes color of the bike will affect the performance.    My red & white '97 seems to be a bike for all seasons!

[Chrisj CMA]

If its never had the vacuum lines replaced...I can almost guarantee thats a huge part of the problem

[98valk]

open up your idle mixture screws 1/2 turn at a time. this is the problem. once it is right u will not need to use the choke. factory settings in the tech manual are for epa and not the best for engine running.  www.factorypro.com tech section has many tech articles for carb tunning.

 I.E. for main jets to keep the same max tune every 25 degree change in ambient temp requires one size main jet change either up or down, this is race max hp condtions.

factory jetting is the best for a wide range of temps in general. all though due to epa and now the ethanol in the fuel (runs leaner) most bikes run better with one size larger pilot jet.

seafoam is not your friend, over priced and can cause hydro lock, much better products out there and at a lower cost.