bike is realy sluggish and low tickover

[Guest Jamsie]

my scoot (200RSV ) is realy sluggish , barely ticks over . wont pass 70 MPH even in 4th gear.

i have ordered a new set of spark plugs and tester in the hope its a plug or 2 fouled up ( would it still run with 2 fouled plugs).

i forgot to check the it the exhausts were getting hot as i got side tracked drying the bike after getting caught in a shower.

i plan to check the coils if new plugs dont fix the issue, is there anything else that i can check

fuel pump is working as i can hear it clicking then stop when ignition is turned on

[Freebird]

Two things I would start with. First of all, verify that it is running on all four cylinders. It's amazing how smooth these bikes will run on only 3. For reasons that I have never understood, there have been more than a few coils go bad or the right rear cylinder.

 

Another thing to check is that all the boots are complete down and sealed on top of the carbs. If the clamps are over tightened, they send to ride up and leave a gap between the boot and the carb throat.

[Guest Jamsie]

just been round to my lockup and scoot is running on front cylinders only, carb boots look ok.

so its either fouled plugs or coils at rear to check.

plugs, tester and plug gap gauge will be here on fri

plan on adding something like seafoam to the tank and taking it for a ride when i get the non firing cylinders working

[V7Goose]

Bet on your plug CAPS being bad (but they can be fixed). Despite what some people say, in my experience the coils on these bikes RARELY go bad. I have had a number of them sent to me that were claimed bad, and they were not. Check the tech library for my article on testing and cleaning the internal parts of the plug caps. When you work on it, be very careful NOT to try and clean the internal resister in any way - even slight rubbing will destroy it.

 

There are certainly many other possibilities for the cylinders to not be working, but start with the easy one.

Goose

[Guest Jamsie]

thanks for the tips , Freebird and Goose.

its dark when i get home and lockup has no electrics , so it will be weekend work.

i did see some specks on resistance for plug caps and coils.

if new plugs dont create a spark i will take the coils and plugs off and check them over .

wont do any harm to clean the contacts if they are ok and apply a smear of dielectic grease either .

[XV1100SE]

Don't put the dielectric grease on the contacts.

[videoarizona]

1: I would look a the ends of the plug wires where they come out of the coils. Mine were corroded. I cut off about 1/2 inch of the wire and stuck it back in. Worked for me...I put dialetric grease on the outside of the wire where it went into coil to keep moisture out.

2: Then look at the wires going to each coil and make sure they are still connected!

3: Pull plugs, clean and gap...or put in 4 new plugs. Fronts are fun to get to...but I was successful by taking off the braces on both sides then using the tool kit spark plug tool to remove.

 

If all this doesn't help...I'd start looking at the fuel lines/rails feeding the back carbs or the carbs themselves.

 

But easy stuff first.,..

 

Keep us posted...

david

[V7Goose]

The plug wires on a 2nd gen are permanently attached to the coils.

 

Even an old nasty plug with 100,000 miles on it is quite unlikely to prevent a cylinder from firing. Still, it never hurts to change them; just do not put any hope in that fixing such a problem. If it makes a difference, count your blessings and buy a lotto ticket.

 

We know from experience that the base of the spring in the plug caps on a 2nd gen always corrode with age, and often this causes very high internal resistance, so that is where you start if you do not have reliable spark.

[videoarizona]

(The plug wires on a 2nd gen are permanently attached to the coils.)

 

Oh...didn't know that. Thanks for correction!!

I was using the first gen as my example of issues.

My bad...

 

[Guest Jamsie]

I had 15 min today to check the plugs before the sun went down and i wouldnt have enough light to work,

checked with new plugs and plug tester and i am getting a spark , so that rules out coils.

i will pull the old plugs tomorrow and test those, if i get a spark then i know its fuel related, either blocked jets or fuel lines to rear carbs

side note its bloody cold in an unheated lockup this time of year

[Guest Jamsie]

got the day off today and weather is above freezing.

managed to pull the carbs, thanks to freebird and goose for 2 great walkthroughs.

i will take them to work tomorrow where i have good lighting in the workshop and srtip , inspect and clean them .

I noticed the coils are burried deep in the bike, just in front of the rear fender and there is a bit corrosion on the contacts which i will clean as a precaution . will i need to remove the right hand headerpipes to reach them, it looks to me the best way to get some access

[Guest Jamsie]

stripped the carbs and they are spotless inside, cleaned outside with carb cleaner and now look like new.

2 screws for carb boots stripped their heads , so i will replace all 4 plus the 2 for the plenum with stainless cap heads .

over the weekend i will start to look at the coils again . a squirt of contact cleaner in the cap and clean up the primary side connections .

[Marcarl]

Check the voltage on the battery, first on the posts and then also on the terminals. You should have 12.4 min not running and over 13 running. If you don't have those values you have an issue.

[Guest Jamsie]

i dont see a reason why a battery would effect 2 cylinders not firing when the other 2 fire perfectly

[Marcarl]

i dont see a reason why a battery would effect 2 cylinders not firing when the other 2 fire perfectly

 

You are right,,, to a point,, but for the time it takes, and, would be a good idea anyways, check the voltage and flow. If the voltage is low, then the power supplied to the coils is reduced, and hence the strength of the spark at the plug isn't as sparkie. Far reach maybe, but costs nothing to check.

[Guest Jamsie]

put the carbs back on today . top tip, unscrew the screws on the clamps , leaving the last few threads , this makes it much easier to put the carbs on and the airbox onto the carbs .

also checked the battery. 12v switched off, 13.93v bike running at 1500 rpm , allbeit with only 2 cylinders firing .

will check the coils over the weekend , the only thing it can be now is a week spark from the rear coils

[V7Goose]

I know you said that the carbs were spotless ... But I would still try another test after you verify the plug caps have no more than 10K of resistance each: Get a can of starter spray ( it is ether, but carb cleaner will work too) and spray a bit in the vacuum port for one of the non-running cylinders while the engine is running. If there is any spark at all, the RPM will pick right up.

 

I do not wish to insult you in any way, but you have an old bike, a very old bike, and frankly, no matter how clean you think the carbs looked, I'd still be surprised if they are not the problem if you find you really do have spark. Do not pass up the most simple tests.

Goose

[Guest Jamsie]

gonna test coils caps and clean all connections on the ignition curcuit . found a vid posted by one of our southern members on youtube

[Guest Jamsie]

pulled off the plug cap from r rear and tested, cap , primary and secondary , all within tollerence.

cleaned connections to coils and plug at ignitor.

still not firing on rear cylinders .

removed a vacuum plug and squirted carb cleaner in while bike was running but no firing from rear.

what i did notice is that the light on the tester was not very bright , i suspect this indicates a bad spark . after lunch i will take 1 side top engine brace off to access front spark plugs and test those to see if there is a difference in brightness .

as the front cylinders are firing i dont suspect the pickup coils .

either my carb cleaning wasnt effective or i have a bad igniter. both rear coils are connected to the igniter by the same connector . had to remove the radiator overflow tank to access it

[Guest Jamsie]

after lunch , i checked for 12v on primary side . 1 wire was 12 v the other around 8, guess this is the trigger wire. wired up plugtester to front R sparkplug and the light on the tested is a hell of a lot brighter, same with the other 2 but R rear is still dim . tested the cap again and it was 10.8k and 13k at the HT wire.

once i put the cap back on the HT lead i couldnt get a reading , tried cutting 1/2 inch of the lead ,screwing the cap on or pushing the cap on i still get no reading .

guess the pressure exerted on the end is breaking the contact somewhere in the ht lead end of the cap. with L rear not firing and a good indication of a spark , i will pull the carbs off again and go over them again making sure i have clear passages and jets . will have to get a new spark plug cap as well

[V7Goose]

There is only one pickup coil, so if any plug is firing, it is fine. You can access the wires on the rear coils from under the bike - not too hard to pull wires and replace them with long nose pliers. All the coils share a common wire(s) from the stop switch - just going from memory instead of bothering to look at the schematic right now, but I'm pretty sure that is 12v, so you should test for that on the wires that are the same color. The unique color wires are the trigger wires from the ingitor.

 

I do not know how many miles are on your bike to suggest if there could be other internal issues or not, but have you checked the vacuum level on all cylinders? At this point it does not really matter if they are in sync, or even what specific vacuum, but you should get strong, similar sized pulses from all cylinders, running or not, if the rings and valves are in decent shape.

Goose

[Guest Jamsie]

the bike only has 15k miles on the clock with paperwork to prove it . when i eventually track down the cause i will prob kick myself for not checking whatever it is first

at least with a strong indication of a spark on L R i can pretty much rule out the igniter for now.. just looked at ricks speed shop and they have resistor caps for less than 5 gbp which is a lot less than the 45 gbp yamaha want . 1 thing i havnt checked which i will do tomorrow is to empty the float bowls on the rear, just to make sure if fuel is actually getting to the floats

but with the high fuel consumption i think it will be getting to there

[Guest Jamsie]

i ordered a ultrasonic cleaner which i will clean my carb jets in .

do i need a specific cleaner or will plain water do , as jets are made from non ferrous metal

 

http://www.ebay.co.uk/itm/181205467330?_trksid=p2057872.m2749.l2648&var=480268792848&ssPageName=STRK%3AMEBIDX%3AIT

[eusa1]

Maybe information that does not apply in this case, but whenever you have any carb or spark concerns on this and many other engines... be sure and check your oil level and make sure it is NOT OVER FULL from gas overflow from stuck floats and such. it is the #1 killer of this bullet proof motor.

 

I would find it a rare possibility for the carbs to be clean on a bike of this age and this few of miles. $.02

[Guest Jamsie]

i ordered the wrong spark plug cap the cap i should of ordered which i have had to reorder from germany is

SD10F NGK cap