Bike problem

[cajun31]

Synchronize

Hey OldYam,

Have you synchronized the carbs lately? That will help with the idle problem.

[oldyam80sg]

No,i have not.I cleaned the carbs out and it seemed to be a little better.It seems to idle somewhat normal.

[oldyam80sg]

The bike seems to idle fine but today when i drove it,it seems to shudder at 40 to 45 mph.I stopped and opened the tank to vent it and drove.No change. When you give it more throttle and drop down a gear it seems to be good.Is it an ignition problem?Could i takle the caps off my spark plug wires.Can they be replaced?

[TopCatGr58]

Hey OldYam,

You say you drop down a gear! What gear are you running in at 40-45, and PLEASE don't say 5th!

If you are, then that's your problem....it's called LUGGING! You're probably not running much over IDLE at that speed and gear! You'll want to keep the rpms at least above 2500.

But, yes, you can get replacement spark plug caps, several sources and styles, resistor, no resistor, angled, etc.! There IS a tech tip about the NGK styles, their model nomenclature, etc. so you know what to order.

You....and the other NOOBIES can find several tips that are NOT linked from the left hand yellow "tech tips" link by scrolling down from the MAIN FORUM PAGE to the tech tips sections and
READ, READ, READ! !
T.C.

[oldyam80sg]

Top Cat, i know what your saying, but it is not correct.If you are riding in fifth gear and going 45 to 50 mph you are not at all lugging that engine .I have been riding for 23 years and have yet to burn out a clutch or cause any engine damage due to this riding style.I dont live on roads that you can go as fast as you want to.How fast do you go before you even reach 5 th gear? The bike must be screaming if you say yes! My opinion.

[HobbyMan]

I ride in 5th at 45mph all the time. Without the 750fd it really doesn't matter. Yes spark plug caps can be replaced. My Dad's just fell off the other day. Does it shudder at all gears in that rpm or just 5th?

[oldyam80sg]

HobbyMan-Thank You! The bike seems to shudder in all gears but not all the time.I poured sea foam inside and the bike seems to idle correctly but the idle is not as smooth as it used to be.I tried opening the tank to vent it but that didnt help.The vaccum lines are fine and the plugs seem to be good.The carbs are clean and was wondering if the wires/caps are the problem.

[oldyam80sg]

more problems

Went for a ride today.Halfway to my storage unit, the bike started to feel like it was not getting enough gas.Switched to prime and the bike felt like it was running on 3 cylinders.Have not looked at the plugs yet but bike shut off 3 times. Switched back to run- nothing changed.Almost full tank of gas.Got bike to storage and would not stay running.Had to pull out choke to keep bike running.Anything else to try?

[bwilding_2000]

How long has it been in storage? Maybe something is plugging a carb?

[oldyam80sg]

Put in storage in Nov 2006.Bike ran fine last year.Started bike on occasion every 3 weeks.No problems.Put stabil in carbs and also some dry gas.Drove bike around storage unit parking lot. Went to take it to my Moms house.Less than a quarter mile from the storage unit,bike hesitated and felt like the gas was not on.Stopped at stoplight and switched the petcocks to prime.Bike ran fine for a little while.Got within a quarter mile from my Moms house and the bike felt like it was running on 3 cylinders.The bike also sounds very different when this problem happens.

[prometheus578]

"Based on the info given..."

Having to use the choke to get fuel means it's not getting fuel by the usual means to run. That it runs using the choke should mean that it's getting fuel to the carb bowls, but maybe not enough.
Pull the fuel lines at the petcock, turn to prime. Fuel should pour out. If not, then it's a petcock issue.
Other than than, time to pull the carbs and clean.

[oldyam80sg]

other findings

I removed the plugs.The outer plugs are wet with gas,the inner plugs are bone dry.the inner part of the exhaust is hot and the outer part of the exhaust is not.What does this mean?The bike feels like it is running on 3 cylinders.

[TopCatGr58]

Hey OldYam,

No aspersions intended, until folks post enough info, we don't know what your experience level is, your mechanical ability, etc.!

I merged your threads, because like you've found out, folks requested info about your storage time, but you had included that at the beginning of your original thread. It's best to keep replying and posting within the same thread so WE can follow what has been done, what has already been suggested, etc.!

You had stated previously that the plugs were a nice tan color, but I'm assuming that they were the old plugs, and may have attained that color from the previous year's riding.

But, now, you have 2 that are wet and cold pipes. The 2 you noted are related electrically in the system, the ignition coil that fires the #1and 4 cylinders. The other link is the pickup coil that triggers the TCI to fire that coil, as well as the TCI!

So....some trouble shooting is next, checking to make sure the ignition coil is good, as well as the Pickup Coil wires under the timing case have not broken, as well as even possibly solder joints going bad on the TCI!?
Good Luck!
T.C.

[oldyam80sg]

Top Cat -Where is the TCI located? Is it the black box under the seat that says TID or something of that nature?Also i looked under the left side cover and removed it.Everything looks intact.I tried wiggling the wires around but nothing happens.Also i put a larger diameter vaccuum hose on that vaccum advance unit.It makes a lot of noise so i put the stock hose back on.Much quieter.How about the caps on the wires itself? If they were bad might i experience the same thing with the bike stalling? Also i pulled out the choke to start it,but the rpms really dont raise when it starts to warm up.

[TopCatGr58]

Hey OldYam,

Yes, the TCI is the black box under the seat.

First, the vacuum advance noise? Is the hose plugged into the #2 carb body port, NOT the #2 intake rubber boot port?
Also, with the cover off, apply suction to that hose anyway you want, and crimp off once you see the timing plate rotate and plunger pull up into the vacuum pot. It should stay there. But if it releases quickly, then you may have a leak in the vacuum diaphragm. Regrettably, they are not available from Yam anymore! Verify the hose doesn't have any cracks where it attached to the vacuum pot.

Do you have an ohmmeter or multimeter/voltmeter??

There are diagnostic steps listed in the TECH TIPS, checking the resistance of the primary windings and secondary high tension windings of the ignition coils. There's also a link to Randy's home page about testing the pickup coils and TCI !

The engine isn't going to run very well on only 2 cylinders with one coil or pickup coil or TCI faulty!

If you don't feel very confident in testing, perhaps there is someone close to you that could lend a hand. In the member's forum, do a search for your state, and you'll find a thread about members registered in your locale!
T.C.