2.0L CU timing problem.

[zxr750]

Iv'e check out few things that I was advised to do last time I ask the question but I'm still no better off. I've tested the mechanical advance is working OK, and that I have the correct timing marks on the pulley. When I try to set the timing to the correct values the marks on the pulley are moving about all over the place because it's running that ruff. It's set at around 24 degrees BTDC and pulling well in the first couple of gears but will only top 65 which is what I want to cruise at not be flat out. The timing was check in the correct way. Any help would be appreciated. Thanks.

[Paul Weeding]

Set the tappets? Done a compression test??

[bigherb]

IThe timing was check in the correct way. Any help would be appreciated. Thanks.

Which was the correct way?

[zxr750]

No not set tappets as there not noisy, would that throw the timing out that much if they do need adjusting? Compression test done, lowest reading was 135 and the highest 155. Timing set by pulling and blocking both vac hoses and pluging idle stabiliser wires together which is a permanent feature it doesn't have one, then using a timing gun with digital RPM display @ around 900, it also has the degrees feature which was set to zero.

[bigherb]

No not set tappets as there not noisy, would that throw the timing out that much if they do need adjusting?

No

Timing set by pulling and blocking both vac hoses

Nope, if you have the correct distributor then the timing is set with both vac hoses connected.

[zxr750]

Both vac lines connected, please tell me the correct way. I think I have the correct distributor,

[bigherb]

Both vac lines connected, please tell me the correct way. I think I have the correct distributor,

You first said vac pipes disconnected and plugged, so what are you doing, pipes connected or disconnected?

[zxr750]

I'm quoting you on the vac lines connected. I set it with them disconnected and plugged. all that said with the lines connected it's not going to advance it the 20+ degrees to make it correct. i'll try it and see. any thing else to look into?

[bigherb]

Set the timing to 5 deg after TDC at 800-900 rpm with both vac line connected .

[zxr750]

I'll try it, but the closer I get ATDC it runs to lumpy or cuts out, timing marks all over the place. What if the carbs were way out, fuel pump not functioning correct, coil problem or an electrical issue? Saying all that carbs are balanced using a unisynch, anything else that could make the timing marks out of place?

[horizontal kipper]

Where in loughborough are you im in shepshed could probably have a look for you.

[zxr750]

PM sent.

[Paul Weeding]

If the tappets are tight that will give you an uneven idle... Only going to take 10 minutes to check them...

[zxr750]

That was one of the next jobs on the list to try, would you say Ratwells way is the best way, pump them up the night before then adjust them in the morning at 1.5 turns in from just touching? Also going to have another look at the vac pipe the one that go's to the T piece on the airbox, when I checked last time I did it before the T piece so that could be at fault. Is it possible for the mechanical advance/retard not to be moving enough, because when I reattach the one that move it CW in turn moves the timing mark the way it needs to go.

[zxr750]

Just tried to set timing to 5 deg ATDC between 800 900 RPM and it's not running right. I had to turn the idle up closer I got to keep it going and it was smoking which it doesn't where it's set to when it's running at it's best, anti CW so the top advance pipe on the can is nearly touching the air box. I'm stumped.