Intermittent hot restart

[Denver98]

 New guy here. Purchased a 98 standard with 40k last week.
This thing is inconsistent in its behavior, so I am at a loss.

 It ran great on the test ride (twice), ran good all the way home. About 60 miles in the rain in stop and go traffic.
 The following weekend rode about 60 miles and stopped at a friends place, 15 minutes or so and would not start. After cranking on it for awhile it finally started but would only run if you were heavy on the throttle, not wanting to be the one to ruin the day I said lets go and off we went wailing on this thing the whole way. After a few miles it straightened up and was good the rest of the way. After sitting for a few hours it started right up and brought me most of the way home running like a champ.
 Most of the way that is. Temp light started flickering and it started popping and farting and would not run at anything less than half throttle again. Oil temp dipstick was showing 200 and the fan cycled on and off a few times.
 Next ride, went about a mile and stopped at a store. 10 min later it started but was popping and farting and again would not stay running at anything less than half throttle. Pulled out pinned the throttle and rowed through the gears, it cleared out by the end of the block.
 Ride #3. Went to same store 10 min later started and ran perfectly. COOL!
Wrong! Pulled up in driveway and it started acting up again. Temp light flickering, no fan and gauge said 150.  ???? 2 mile ride.

 Here is what I have done after the ole Google searching.
1) swapped Pulsestar plugs for some stock ones.
2) checked air filter, brand new K&N.
3) pulled fuel valve to clean it. It was spotless and diaphragm was good. Screen was clean. Held 5" vacuum with mighty vac, this included the hose that goes to carb. Tested to make sure it opened and closed properly both vac and mechanically.
4) checked vent hose, no kinks and could blow through it.
5) after reinstalling tank rechecked all hoses for kinks.

 A couple oddities here, I noticed the temp light flickers on and off when it is being uncooperative. Oil dipstick was showing 150. Should I be looking at an electrical issue and not fuel?
 The other thing is the choke does not work, the bars on both banks slide back and forth and the brass rods move in and out of the carbs but there is no effect.

 I am at a loss here. Any ideas?

[Bigun]

Try running a can of techron through the fuel system. Check your coolant to make sure it's good and maybe change your thermostat while you are at it. The having to run it at half throttle or more says plugged slow jets to me.

[Denver98]

 Radiator is full and the overflow bottle is about half.
What is odd is that it only does it after running awhile. The first two times was after an hour or so and the next time was about 5 min. Either way a can of 44K couldn't hurt.
 What has me scratching my head is the temp light flashing at 150.
And it runs fine on a cold start.

[fordmano]

May sound like a dumb question, but are you sure the choke is in the off position? No you can't ask me how I thought of this scenario!

The light could be bad connection or a short? 

[sandy]

The flickering hot light is a problem some Valks have. Mine's been doing it for years with no real overheating issues. I agree you might have clogged slow jets.

[Chrisj CMA]

Sounds like vacuum leaks........if its not been desmogged I bet it has cracked vacuum lines to both center carbs, also the one from intake #6 to the petcock. 

the intake clamp screws are scary loose if you have never tightened them. 

check all that and maybe problem gone

[Michvalk]

The bike does not have a choke, per say, but an enrichment circuit. Adds more fuel to the mix. If the "choke" isn't releasing all the way, the bike would run rich at anything less than wide open. Running carb cleaner in a heavy dose is not a bad idea. You might look for vacuum leaks. There are a number of clamps on the carbs (3 each) that loosen and cause problems with the running. Might check the intake bolts while you are in there. (Not too tight, just snug) and check the vacuum lines and plugs on the back of the intakes. Just some suggestions

[John Schmidt]

Has it had the ECT mod done to it? If installed with a potentiometer it may have gone bad. They're installed in the temp sensing circuit.

[Daniel Meyer]

Check the battery, preferably under load.

[Denver98]

May sound like a dumb question, but are you sure the choke is in the off position? No you can't ask me how I thought of this scenario!

The light could be bad connection or a short? 

I believe so, when I got it the cables were out of adjustment and did nothing. After adjusting out the slack the slider bars move full stroke and move the brass rods in and out of the carbs now.

[Denver98]

The flickering hot light is a problem some Valks have. Mine's been doing it for years with no real overheating issues. I agree you might have clogged slow jets.

 The light only seems to flicker when it is acting up, otherwise it is off.
Another vote for gunked up carbs......     

[Denver98]

Sounds like vacuum leaks........if its not been desmogged I bet it has cracked vacuum lines to both center carbs, also the one from intake #6 to the petcock. 

the intake clamp screws are scary loose if you have never tightened them. 

check all that and maybe problem gone

 It appears to be a CA model and the emission stuff is gone. There are caps on the lines from the carbs.
#6 is on the left rear correct? If so I do not see a vac port on that one. The fuel valve is connected to the middle right carb.
 The intake clamps you can see with the bike assembled were finger tight, I snugged those up the other day.

[Denver98]

The bike does not have a choke, per say, but an enrichment circuit. Adds more fuel to the mix. If the "choke" isn't releasing all the way, the bike would run rich at anything less than wide open. Running carb cleaner in a heavy dose is not a bad idea. You might look for vacuum leaks. There are a number of clamps on the carbs (3 each) that loosen and cause problems with the running. Might check the intake bolts while you are in there. (Not too tight, just snug) and check the vacuum lines and plugs on the back of the intakes. Just some suggestions

 The slider bars move to the end of the slot in both directions after I took up the slack in the cables and little brass rods appear to retract fully.
 Put a wrench on the intake bolts at the head when I tightened the clamps on the manifold, those were all tight.
 Another vote for gunked up carbs......   
 Will have to go over it again for leaks and loose bits.

[Denver98]

Has it had the ECT mod done to it? If installed with a potentiometer it may have gone bad. They're installed in the temp sensing circuit.

 ECT mod? Had to look that one up. I do not recall seeing a pot sticking out anywhere, but will have to pull the cover and look for any diodes spliced in.

[R J]

You said the choke, (fuel enricher) didn't work.

Now my question is did you just go to the resistance and no farther.

Once you hit resistance, push the choke lever some more.   That is when the choke does its job.    The little black lever should be pointed straight across to the right handlebar.

Did you check the tank for rust when you had it off?       Sounds like you might have some rust in the tank and a few pieces get through to the carbs.   If you find rust, you will need to clean that crap out.     I don't really recommend a in line filter, but I figure yours is an exception.

Good luck.

While you are in there, check all the battery cables, both ends.   

[Denver98]

Check the battery, preferably under load.

 It has a new Shorai, but I have not put a meter on it. I am guessing it is ok as it was eager to crank away without grinding down the first time it would not start.

[Denver98]

You said the choke, (fuel enricher) didn't work.

Now my question is did you just go to the resistance and no farther.

Once you hit resistance, push the choke lever some more.   That is when the choke does its job.    The little black lever should be pointed straight across to the right handlebar.

Did you check the tank for rust when you had it off?       Sounds like you might have some rust in the tank and a few pieces get through to the carbs.   If you find rust, you will need to clean that crap out.     I don't really recommend a in line filter, but I figure yours is an exception.

Good luck.

While you are in there, check all the battery cables, both ends.   

 The lever moves the slider bars the full length of the slot, it is stiff but does go the full length of travel.
Moving the lever does not change the idle speed at all. It will start first try with a blip of the throttle but will barely stay running till it warms up.
 There does not appear to be any rust, looking through the filler cap it is nice and shiny inside. No debris came out when I pulled the valve, the screen was clean as was the inside of the valve.
 Will have to check the cable connections.

[Denver98]

 I wanted to say thank you for everyones help.

Summary
 Dump a can of 44K in it and take it out for a good flogging.
 Check all vac hoses for leaks, or just replace them all.
 Look for a ECT mod gone bad.
 Check battery voltage and connections.
 Check the intake clamps for tightness and the boots for splits.

I have to work tomorrow so I do not know how much I will be able to get done.

[John Schmidt]

You mentioned "blip" the throttle, keep in mind these carbs don't have an accelerator pump. Therefore doing anything with the throttle doesn't assist in starting because it doesn't shoot any gas into the system if done before hitting the starter. It's not at all like the carbs on the older cars where you could pump the gas pedal and it would shoot raw fuel into the intake.

[Firefighter]

I think your problem is electrical. Check battery voltage and when the problem occurs check voltage through the frame ( battery positive to frame not battery negative). Bet your frame is not grounding correctly all the time. Run a jumper from battery negative to frame, try again. Some of important ignition parts are grounded on the frame. If voltage to computer is low, bad ground or positive, engine will miss as you stated, and could be trying to ground through temp lite also. You can attach a multi meter to batt. positive and frame, go ride and see if voltage drops. Good luck and let us know.

[Denver98]

You mentioned "blip" the throttle, keep in mind these carbs don't have an accelerator pump. Therefore doing anything with the throttle doesn't assist in starting because it doesn't shoot any gas into the system if done before hitting the starter. It's not at all like the carbs on the older cars where you could pump the gas pedal and it would shoot raw fuel into the intake.

 Not like the old days when you had to crack the throttle to set the choke or give it a squirt first.
If you just hit the starter it will just crank. When you hit the starter you have to "blip" the throttle while cranking and it lights right up.

[Denver98]

I think your problem is electrical. Check battery voltage and when the problem occurs check voltage through the frame ( battery positive to frame not battery negative). Bet your frame is not grounding correctly all the time. Run a jumper from battery negative to frame, try again. Some of important ignition parts are grounded on the frame. If voltage to computer is low, bad ground or positive, engine will miss as you stated, and could be trying to ground through temp lite also. You can attach a multi meter to batt. positive and frame, go ride and see if voltage drops. Good luck and let us know.

 Good idea, I did not think to check for a chassis ground. I do recall the negative cable going to the block on the lower left side but nothing else. Might have to put a wrench on the motor mounts also.
 Just got home from work, managed to pick up a can of 44K and some vacuum line. Heading out to garage now.

[R J]

On MGM a long time back, I run a 2nd cable from the ground on the engine to the frame.

Like, battery ground post to engine block, same port I run another cable to the frame for a final ground.

I wasn't really have electrical issues at the time but I had built enough race cars and race motorcycles to run the extra ground cables.

My Chevy Trike when I bought it, it was supposed to of been completely wired.  All I did was put the rear end under it, the engine and a radiator.    Then I run disc brakes and started riding it.

Several times I had electrical gremlins that made me rub my head ands shake it several times.       A buddy of mine who has an electrical repair shop, we were talking about my gremlins.    He asked if I had the battery grounded to the frame or just terminated at the engine.

Told him I didn't know but I was headed home to find out.      Added the 2nd cable and all them Gremlins disappeared out of my bell.    I've even forgotten who gave it to me.    It is still hanging on the trailer hitch chain loops.

[Denver98]

 Update, the bike was put on the back burner for a few weeks. We got hit with some serious rain here in CO, every thing is under water.
 Anyhow I tore the bike apart, tank, airbox, seat, side panels, etc... Cleaned all the electrical connections I could find and added a ground strap to the frame.
 While in there nothing jumped out at me as a "aha there it is" with the exception of one thing.
 I mentioned before that a PO had put a Shorai battery in there. Well when I put the ground strap on I noticed that the terminals on the battery were wider than the guide tabs on the cables. So the contact was on the tabs and the middle point of the cable was crushed under the bolt. To correct this I flattened out the tabs and straightened out the part that bowed under the bolt.
 Put about 150 miles on it today and it ran beautifully, not a pop or a fart at all. No temp light flickers either. We ran into some stop and go traffic a few times and no issues there either, fan cycled on and off like it should.
 Only one ride so far since doing so but it looks like the problem is resolved. Finally got a decent day in since purchasing it. I am starting to like this bike. 

[Daniel Meyer]

 

[R J]

Good to hear ya got her fixed.

 

[Patrick]

Your problem really seemed like it would make one talk to themselves ! Its always good to hear to what the fix was. Good info.

[HayHauler]

Thanks for the solution denver!  Hope all is well with the water now.  Pictures on the news were really bad.

I had a thought when you mentioned the type of battery you had.  I had no idea that it would turn out to be the battery connections and the posts.

Hay 
JImmyt