The long road of taming my Tiger

[P3aK]

Ok, I'm back at my parents garage and picking this up again.

Went back to 2 1/4 turns on the mix screws as it should be (was), idle and low is good so I will leave it there. I've opened up the cam cover and re-measured the valve-intakes. No change since I shimmed them, all good.

I've opened up and looked at the cam timing plate and put the whole thing in TDC (or whatever it's called). It all lines up very well.
The two arrows on the cam shaft sprockets pointing towards each other and parallel with the cylinder body and the timing plate towards the pickup coil.
There is almost no slack in the cam chain, we're talking 1-2mm only.

I haven't liked the look of the air filter lately so I ordered one last time I was here and now has it fitted. Spanking new K&N, so it sure as hell breathes now (if it wasn't already). But alas, no change what so ever.

Now what? It's still running and running reasonably well, until I hit 6.5-7k rpms, it kind of stops. And in 4th, 5th 6th, I struggle to even get past 5k rpms.

I'm out of ideas again. Help! 

[London_Phil]

Fuel starvation?

[P3aK]

It's a good idea but... how though?

The carbs are cleaner then they've ever been. All jets have been out 3 times after the industrial steam bath and blown with compressed air (driven perhaps 20km since last clean). There are no filters inside the tank, no inline filter between the no.2 and no.3. Only filter is a big clear inline down from the petcock which is rather new and I can't see any dirt inside it. After I run it, it's still filled with petrol, no loss of level.

No change of flow rate if I open or close the tank lid. Flushed all the old petrol from the tank and put new in. I've re-routed the fuel line underneath the carbs instead of over and between, to reduce kinks (long ago, before any troubles).

The only things I can think of try for more fuel is to open the mixture screws to 2.5-3 turns and throw in 1mm needle shims (I would try 0.7 or 0.5mm but I don't have any and I live far away from any such store).

Tomorrow I will also pull the carbs for the 923759374th time and I will polish the slides and internals with some ultra fine grit cloth/sponge to see if that makes a difference. I doubt anything will change though. 

[ssevy]

I would get a length of clear fuel line and go back to the original duckbill and bin the inline. I tried one of those clear glass inline filters on my Legend once, and the fuel rate couldn't keep up at high revs.
If I am thinking logically, it sounds like the symptom is an actual loss of horsepower, as the higher the gear, the more challeging the mechanical advantage - like having a lever that is too short to move a big rock.
Thinking what might cause a loss of hp...
If it were compression related, I think it would be a hard starting cuss, so I don't think it's rings or valves, but a compression or leakdown test would confirm this.
Fuel is still a possibility, but if you install a transparent fuel line you will have a means to verify.
Air in and out you seem to have covered, but always easy to squirt some carb cleaner around to check for vacuum leaks just to be sure.
Sorry I'm not more helpful, but keep at it and you'll get it sorted. I've chased some strange symptoms down on both my triples, and I just keep thinking "air, fuel and spark"; it's got to be one or more of these.

[fishnbiker]

How about some more photos of this 3 into 1 exhaust?

[davetheworv]

I would ditch the inline filter,the flow rate may not be enough.or it could have been fitted wrong way round,I have heard of this before. if it doesnt help at least it hasnt cost you or taken much time to eliminate

[GavD]

Ok, I'm back at my parents garage and picking this up again.

Went back to 2 1/4 turns on the mix screws as it should be (was), idle and low is good so I will leave it there. I've opened up the cam cover and re-measured the valve-intakes. No change since I shimmed them, all good.

I've opened up and looked at the cam timing plate and put the whole thing in TDC (or whatever it's called). It all lines up very well.
The two arrows on the cam shaft sprockets pointing towards each other and parallel with the cylinder body and the timing plate towards the pickup coil.
There is almost no slack in the cam chain, we're talking 1-2mm only.

I haven't liked the look of the air filter lately so I ordered one last time I was here and now has it fitted. Spanking new K&N, so it sure as hell breathes now (if it wasn't already). But alas, no change what so ever.

Now what? It's still running and running reasonably well, until I hit 6.5-7k rpms, it kind of stops. And in 4th, 5th 6th, I struggle to even get past 5k rpms.

I'm out of ideas again. Help! 

The only difference between yours and mine now is the K&N. As these pass more air than the standard, your symptoms may suggest there isn't enough fuel getting through at high revs and that your main jets are a little small.

When you say you changed the air filter, was it just the filter or the housing as well. I changed the whole housing (it comes with a new triumph air filter) recently because after 18 years it was getting various cracks in it and i thought too much air was getting in through these. This improved the throttle response noticeably and the bike starts better - I only need half choke now.

Maybe a combination of K&N and an old cracked air box housing is letting too much air through for your 105 mains?

[JayDub]

just a wild though but, is the throttle cable seated and adjusted correctly, ie fully opening? 

[P3aK]

I've done the starter gas around airbox/rubber boots and it doesn't pick up any revs until I get too close to the intake snorkel in the back. I've sealed the auxiliaries my self with sealant and inspected the main airbox properly and it doesn't steal any air.

GavD I only changed the air filter as the box is in good condition. I have one rubber boot that is a bit annoying but I sort of mended it 2 days ago and I'm spraying starter gas around to check for leaks.

I know the K&N gives a bit more air, but it hasn't made my problem better or worse. So the impact isn't big enough to make a change in this particular case.

I'll have a look at the throttle wire and see if I can pull any more at the carbs when full throttle. Doubt that's the case as I've dialed it in pretty good,  but we'll see.

I'm gonna try without fuel filter and see if it makes a difference.

It's very easy to start since I shimmed the valves. Don't know compression numbers as I don't own tools to test.

Hmm, wonder where I could get a clear fuel line around here on a Sunday?

[GavD]

Is your chassis number 55616 or higher?

the reason I ask is, that is the number that should have keihins fitted as standard. Just wondering if someone has fitted a set of keihins off a different model that weren't correct for the tiger. I believe there were differences in the vacuum slider between models.

[P3aK]

It's done!!! 


Ok so a bit of history first.

When I had the bike apart for changing the sprag clutch I also went through the carbs. Of course I managed to misplace one of the jets but I didn't care much since I'd read on this forum about the 105 mains, 40 pilots (mine came from PO with 38 for some reason) and the 1mm needle shims for Kehins.

So I naturally ordered and fitted that before the engine was finished and when I finally got the bike together I was eager to see what the bike had to offer (I'd only done 250km on it before full strip).

Well, kinda like now it ran like shit. I tried everything and nothing would help. Until my dad told me to take the needle shims out of the carbs. I laughed at him telling him he knew nothing. But eventually I relented and lo and behold, it suddenly worked like it should.

What I did now... was to reverse that decision. I put the 1mm needle shims in again. Suddenly it all works.

So fixing the valves... which is the only thing I really did, made it want shims on the needles? (It's the only way I can read this situation.) Yes I added the K&N air filter later, but I already had this problem before. If anything,  it should have worked better before with the OEM air filter if it gets so much less air.

I'm certain that it would run almost as good as now if I put in the old filter.

So fuel starvation was the problem indeed. Just that the fix wasn't that obvious, especially with my previous experience in mind.

This also brings up another thought, shimmed needle would appear to affect the midrange (which it really did) but also the top range (which was non existent before) that is great now. According to the theory I've read it shouldn't.

I feel like I understand this bike less and less the more stuffs I fix.

Anyway, I'm putting it together and going for a run tomorrow. I'm gonna celebrate with some beers now. 

[GavD]

 

[Bixxer Bob]

Needle is 1/4 - 3/4 throttle, 3/4 - 4/4 is min jet.  By shimming you have made the whole mid range richer.

[P3aK]

@Bixxer Bob: Yeah exactly, it does (and should) affect 1/4 to 3/4 (midrange).

But the biggest change for me is that it changed 3/4 to 4/4 (top range) (which it shouldn't).
Semantics perhaps, but top range for me would be 6.5k rpm to 8.5k rpms and that's exactly what was non existent before. Now it's just there.

Happy days!

[Sin_Tiger]

 

It's been flogged to death but putting it back to stock works almost every time.