Finally: valves check OK but not always running on 3

[MtheTiger]

Well...finally the weather here in the Netherlands cleared up enough to get started on my maintenance and overhaul.

(Tigger 1997 with Daytona cams and apparently rejetted because both snorkels open. It has done app. 54K kms.)

Two weeks ago Tigger was'nt running on all three though. It starts always OK and runs fine but this time one cilinder quit on the highway. First I checked if would come alive again above 4500 revs and it did but not every time. I managed to limp home for some checks & maintenance.....as I've read here it would be probably the coils, valves or lack of fuel.

Todays valve check gave the following clearances:

OUT   19 19    17 19    22 20
IN      14 12    14 14    14 14



So, I'm pretty happy with this result. Only one exhaust valve is 0.02mm out of spec. Since it is less than 0.05 I guess I can let it just sit there?
The valves turn out OK-ish so I checked the coils. All three are PVL coils and appear to be in good condition. Could it be one of the PVL coils is dying on me? How can I test the coils ?

While being in there I did check the timing and found that with the crank being on T1 both arrows on the cams are not precise pointing at each other. One is slightly off....not enough to be a skipped tooth though I think. Could this be the culprit? What does the marking 24 mean ?






The third possible couse could be lack of fuel. I haven't checked this yet.
I guess this will probably be the cause of Tigger not running on all three because before it started to happen I managed to let her tip over while standing still :oops:  Could it be this freed the crud in the carbs and/or tank and blocking the fuel ?

Any advice from the experts what to do next and how to do it is appreciated.

[Mustang]

your timing marks look fine , if you set the t1 mark more towards the center of the pickup sensor your cam arrows will probably be dead on .

valve clearances are fine to leave as is ....

clean the carbs thoroughly especially the pilot jets , seeing how you can make all three run on 4500 rpm and up it could well be a plugged pilot
if that all checks out and the symptoms are still there its time to try some new coils .

also make sure the cone filter in the fuel pipe where it connects between #2 and 3 carb is clean while you have the carbs out

[MtheTiger]

Thanx for the speedy replie Mustang...as always  

your timing marks look fine , if you set the t1 mark more towards the center of the pickup sensor your cam arrows will probably be dead on .

When I do this the arrows will be slightly more out of sync than now cause the intake cam arrow will move up and the exhaust cam arrow will move down. Hope this isn't a skipped tooth after all.....

Tomorrow I'll pull the carbs and clean them and the airbox (hope I can split it without demolishing it).
I have the later Mikuni's (eng nr 55616 and higher at Bike Bandits schematics).
Does this cleaning mess up the carb sync because I do not have the equipment or knowledge for readjusting this :roll:
Are there any parts I have to renew such as orings while I'm in there?

[Mustang]

even if the cam chain is shot and the marks don't quite line up it would not make it drop a cylinder intermittently ..................
you won't mess up the carb sync as long as you don't touch the adjusting screws on the carb linkages , and save yourself some grief and unhook the throttle cable at the twist grip so you can work on the carbs on the bench .it's a lot easier to unhook the cable at the grip then the carb linkage .
the orings for the float assembly's can only be had from  triumph when you buy the whole float assembly ..WTF
but they are just standard buna orings and you should be able to get anywhere .

Mcmaster carr sells orings but that is here in the USA

when you reassemble make sure and put a few drops of oil on the float assem orings makes it go back together with no drama and the orings slide right into the pockets in the carb body .

take the pilot jets out and make sure they are not clogged , my moneys on coils but it is worth it to check the carbs first , and the pvl coils don't usually fail like the gill coils do . but it does have the problem like failed coils
if it runs good cold and then starts to act up as the temperature increases  it's probably coils

[MtheTiger]

Well...pulled the carbs and airbox today and

- demolished the airbox trying to get it open...will need a new one now
- found a lot of crap in the tiny inline filter...grains of sand and what not
- saw that the orings on the T-piece between carbs 2 & 3 are shot

So I have to pull carb 3 from the rest to replace it.
Hope I can do this without disturbing the sync a whole lot.....

[Mustang]

and that's probably the cylinder that gets dropped intermittently
it is probably going to run a lot better when you keep the fuel going in the carbs
and your gas mileage will certainly improve too

[MtheTiger]

Well, today I've done the following

- Assembled carbs (all orings replaced) back on bike
- New airbox (what a F@#&% PITA to connect to carbs)
- New NGK plugs (got spark on all three)
- Lubed throttlecable back on bike (was still in good nick)
- Flushed tank with new petcock on bike
- Synchronised carbs
- Gone for a ride................  :D

10 mins later when Tigger got hot the same shit started to happen as before so I think I've got a pickup sensor going south on me.

Symptoms are:
- When hot (motorway) Tigger dies slowly ... a bit like fuel starvation (haven't checked if the tach zeroed when this happens...forgot)
- When trying to start the red light on the dash blinks in sync with startermotor cranking
- Will start again when cooled down
- After about a mile dies again

Fuel starvation is not the problem (cannot be). Neither are the coils because when cooled down enough she starts again happy on 3 cilinders.

[Mustang]

it does sound like the ignition pick up sensor , when you replace it set it so that the air gap to the triggers is about the thickness of a match book cover , I forget what the exact spec is but it's in the manual

match book cover works pretty damn good on the side of the road  :shock:

[MtheTiger]

Okidoki
Sensor ordered and will be inserted in Tigger coming saturday.....
Too bad there's no aftermarket replacement available..... little shit costs € 71,00  

[MtheTiger]

Sensor swapped and all = OK again.
No more running on two or pretending to be out of gas.
However, when I rev anything below 6k Tigger runs on three cilinders allright but she sounds (and feels) somewhat hoarse. When I open the taps it's gone and she runs like stig. Could this also be the coils?