Kawi2strokes.com Forum

With the greatest of respect, the gentleman did infer that the bike improved as he went down in jet size.

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'You don't stop riding because your getting old, you get old because you stop riding'

71 Kawasaki H1A
2005 MV Agusta 1000s
1990 TZ 250A (Reverse Cylinder)
1996 RS 250R Honda
1996 RS 250 Aprilia

But there are questions, as one size jet will not cause the symptoms he describes. Unless (which I personally think is unlikely) that 90 is actually very rich. Black and 4 stroking is usually 3 or more jet sizes too big.

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Twist the throttle, tilt the horizon, and have a great time. What triples are all about...........

greens,

A few thoughts:
Your initial symptom of this thing falling on its face/rich at revs is almost always linked to a clogged exhaust. Yes, I saw you stated your baffles are clear. However, some of the later exhausts (IE KH500) have some sort of additional wire screen that plugs or comes adrift inside the pipe. This too can restrict the exhaust. Varmints such as mice can also build nests . Have you actually looked into the pipe with a bright light with the baffles out?

You say you have properly set the float levels. What measurement/method did you use? The easiest way is to simply invert the carb and measure the height of the float to the gasket surface (no gasket fitted). The correct measurement is 23-25mm. I usually go to the 25mm level as the level will drift lower (carb inverted) as parts seat/wear during service.

Any chance your floats have leaked fuel into them? This to can cause excessive richness.

Timing: Have you verified this with a strobe light? As stated in the past the 500 normally runs best in the 24-25 degree advanced before TDC position. (You are correctly timed on the advanced side and not the retard side of TDC?)

Ignition:
Your rev limiting/rich condition can also be linked to a tired CDI. Yes, at idle/low revs it runs ok. However at high revs/under load it cannot properly fire the plugs and gives a "rich" situe on the plugs. Defective CDI units have also been known to fire at erratic timing as the RPMs increase (often greatly retarding timing) which again will show a false rich condition. Do you have access to a known good CDI to try?

The appropriate firing order on the late 500s (74 and on) is determined by the slip ring/brushes on the end of your alternator rotor. What is the condition of these (is the slip ring clean and brush length within spec?. Have a look while its running. There should be little arcing going on here during operation if the CDI units are proper too.

J

PS, Any chance there is a mouse nest /restriction within your stock air box? Did you use heavy oil on the K&N filter (or over oil it)?

I have been thinking about this quite a lot and when I woke this morning I was thinking that unless its confirmed that genuine Mikuni jets are fitted all this procrastination about jet size is purely academic as (With the greatest of respect) the discussion from some members points of view is clearly based on 'previous' and I would think 'well documented' experiences of this model which I can only assume would have genuine Mikuni OEM parts fitted.

Through my own personal recent carburation experiences It could be that its just an apple and pears situation.

OEM (Mikuni) carburetor set up = Apples
greens 8 (Keyster or WHY ???) carburetor set up = Pears

Sure I admit that I edited my earlier post!! greens8 gave me the strong opinion that running 90's or less would be the WTG as to quote:- "The best Ive had it before the rebuild was with 90s."

I was thinking that fitting 85's and doing a plug chop would have conclusively proved one way or another if it was running rich or not. But after considering it for a while I thought that it better to err on the direction of caution so hence my suggestion to split the difference at 87.5's.

At the time I posted the original it was about 8.30 in the evening in Oz and at the time I edited greens8 would have most probably been in bed as I think it would have been 1.22am in Oz, I'm pretty sure that he wouldn't be feverishly ripping carbs apart and changing jets on the strength of this thread.

If it is only carburation conducting a 'Plug Chop' is the only way to go to sort jetting out, it really doesn't get any simpler than that!! otherwise its just If the symptoms still persist I would then think that it must be electrical and so what Looney Cylinders has posted must surely be top of the list.

BTW how many miles have you covered since the rebuild?

_________________
'You don't stop riding because your getting old, you get old because you stop riding'

71 Kawasaki H1A
2005 MV Agusta 1000s
1990 TZ 250A (Reverse Cylinder)
1996 RS 250R Honda
1996 RS 250 Aprilia

Listen guys; thanks all of you for your input.
For Ade; mate I just read your last post and just to clear up a few things, firstly I stated that it had lousy comp before I rebuilt it, that would have been quite clear. Secondly if you read some of my posts you`d have noticed that I asked for and got heaps of advice on run in (look under `run in` if you have trouble) and chose to use Ja-moo`s advice which I also stated. The good comp is now, OK.
I also stated that I had run with the air box disconnected, remember. As for the charts - I have all the charts and can read just fine. Also stated I removed all the carby parts from the kit except the fuel inlet valve and gaskets as it was not original as advised by other members and was happy I did so.
Even `I` knew that the F and KH models run differrent specs hence my post`Identification of my model`.
Whilst on the one hand I appreciate your attempts to help I can`t help commenting that we are not in the same boat because I read up before commenting and having asked for advice and got it, I listen. That`s the differrence. No offence intended mate and thanks for the good intentions.

Its sorted then? what was wrong with it? did you conduct a plug chop?

_________________
'You don't stop riding because your getting old, you get old because you stop riding'

71 Kawasaki H1A
2005 MV Agusta 1000s
1990 TZ 250A (Reverse Cylinder)
1996 RS 250R Honda
1996 RS 250 Aprilia

No Ade it`s not sorted as I need to wait until Friday afternoon at the earliest or Sat morning to fiddle. I will change my mains back to 92.5, timing to 25degrees as advised, now I have a distance below Tdc to use, and run it (3.45mm). It may take a couple of tries either side of that mark (25). If that doesn`t help I`ll buy the pods which are usually said to be suitable for the 750 also and so should not restrict air-flow and see if that makes the differrence. Failing that; I haven`t thought that far ahead yet. Ade, could you do me a favour and just let it go. I did not join this board to argue.

Nor did I...................Very best of luck.

_________________
'You don't stop riding because your getting old, you get old because you stop riding'

71 Kawasaki H1A
2005 MV Agusta 1000s
1990 TZ 250A (Reverse Cylinder)
1996 RS 250R Honda
1996 RS 250 Aprilia

For what it's worth, H1-E ignition timing is 2.94mm BTDC (23 deg), not 3.45 (25 deg).

Thanks Gerrit we all know the manual or base settings but some of the more experienced triple owners advise the differrent timing of 25, which I will try when it stops raining.