engine and drivetrain Please Analyse My Tii Plugs

[PaulTWinterton]

I'm hoping some will give me opinions of my rough running and potential fixes.

Engine starts after 12 rotations (too long), idles at 1300rmp til warm and then down to 900rpm when warm (good). It idles with some erratic vibration(not so good).

900-2000 runs smooth

2000-3000 (cruising) runs rough (holding back)

3000up runs smooth.

Miles/Gal 18/19 combined (should be 25?).

All new ignition parts and tuned to spec,

KFish linkage set to spec and tight.

I'm starting to think it is a weak injector on plug 4 or bad valve.

Please look at the following picture and pass on your comments.

I sure need some experienced input.

Thanks for reading,

Paul Winterton

Vancouver, Canada

73 Inka Tii, 2762958

[aa/fd]

#4 looks like it has a slight oil control issue rather than over rich

[roadhog0]

I agree with the oil issue. Could be a stuck/warn ring? it doesnt have the carbony look of too rich, has the black oily look.

I get 22-24 Hwy on my Carbed 02 (32/36 Web). 19 or 20 mixed. So I would say you aren't too far off on mileage.

[c.d.iesel]

compress test readings ?

fuel pressure reading ?

#4 check valve on the injection pump ?

how old are the valve guide seals ?

[aa/fd]

Mileage with my Tii is 15 to 18 in town and out on the highway 28 to 30.

A lot of the around town is the driver (me) It is way more fun to WOT from stoplights than being conservative.

[Richard]

I cant say for sure on the dirty plug. But in my experience the other three show very lean..Around town driving is going to leave somthing.

[ray_]

Which plugs are those? All 4 are the same heat range, right?

GL,

Ray

[PaulTWinterton]

More answers:

- Comp test: 145/145/140/145 with screw-in guage.

- Fuel pressure: Not tested yet, but wouldn't low show on all plugs?

- #4 check valve on pump. What am I looking for if I inspect?

- Age of valve guide seats: 2012 - 1973 = 39 years approx.

Engine has just over 70,000 miles on it.

- Plug type: NGK BPR6ES

PW

[Richard]

I still think its mixture. Recheck the warm up regulator. And finally take the top off the KF and clean the assy

[PaulTWinterton]

Richard,

That's encouraging, as burnt valves or faulty injectors is a lot more difficult to rectify.

You say "take off the top of the KF and clean". Do you mean the check valves under the hex head bolts? I haven't been in there, so any info is helpful. I do have the KFish re&re document.

Paul

[TobyB]

I agree with Richard-- 1-3 DO look awfully lean. I'd go down one

air corrector on the race car... but just one.

On a street car I'd go up a jet.

Which doesn't help much with a tii, I know....

t

[ray_]

CD asked about the valve guide seals

Looking, here, looks like oil: http://www.motocrossgear.com/wp-content/uploads/2011/12/plugdiag.jpg

I also think you are running lean. Maybe check for vacuum leaks too.

GL,

Ray

More answers:

- Comp test: 145/145/140/145 with screw-in guage.

- Fuel pressure: Not tested yet, but wouldn't low show on all plugs?

- #4 check valve on pump. What am I looking for if I inspect?

- Age of valve guide seats: 2012 - 1973 = 39 years approx.

Engine has just over 70,000 miles on it.

- Plug type: NGK BPR6ES

PW

[Richard]

Paul,

Yes take off the 4 hex head screws after disconnecting the FI lines and marking them. Disconnect where they attach to the valves on the pump. The top of the pump comes off easily. Nothing goes sprong and flies out. Check the action of the valves. They do gum up.

[PaulTWinterton]

Thanks Richard and all,

I'm going to do a fuel pressure check, open up the top of the KFish and check all fuel screens and valves.

I'll increase the mixture slightly as well. See where it gets me.

Thanks again,

Paul Winterton

Vancouver Canada

73 Inka Tii 2762958

[Richard]

If you enable your PM I can send you my phone