New Engine

Sounds like it might be running too hot. Lack of cooling air, and possibly running too lean.

More air: jam an empty aluminum coke can between the engine lid and rear apron. Secure it in place with.....

...you knew it, DUCT TAPE :D

Then go for another, easy drive.

Lean condition: listen for pinging noises from the engine, especially when accelerating full throttle with too big gear. Like climbing a hill in 4th gear. Take note how easiuly the engine stops, does it want to run on after you turn the ignition off?

In any case, don't drive it much until you have the mixture perfectly adjusted by a pro.

Jan

Thanks Jan

I'll try the extra "cooling" tomorrow and will also go and get an co test, should be about 2-3% I think. I'll check the jet in there, I have a 130 main lying around, I might put that in!

Regards Kevin

Hi Jan

Could it not be because the engine is so new and tight that it's running very hot? I'll let you know what the co content is.

Thanks Regards Kevin

It could well be because everything is new, but it should "wear in" quite soon. Within a day or two the worst grinding and binding will be over. (Change the oil and filter (if you have one) after 150 miles of driving.... assuming the first oil change was done after the engine was run only 20 minutes)

Jan

neighborhood.

Hi Jan

According to the engine builder he ran the engine for 15 - 20 minutes, cooled it down adjusted values and gave it to me with new oil and adjusted valves and I must go back to him in about 400 miles of travelling for readjustment!

I went to our local carb centre (bunch of monkey's run it) they did a CO test it was round 4% at idle and 5.6% at roughly 3000rpm! So it's definitely running rich!!! I also took it for another run, the oil pressure was much higher, and the engine seemed a bit cooler but fair enough it's been freezing today about 18 - 20C yesterday was about 35 - 38C!

Thanks again for all your help!

Regards Kevin

Excellent. Sounds very good to me.

Yes,too rich. You are targeting roughly 2%. WAY rich mixture will also cause overheating, and it certainly does cause more wear. The extra gasoline washes too much of the oil film off from the cylinder walls. *Slightly* rich mixture will have a cooling effect though.

Jan

Thanks Jan

I'll drop the main jet down one size but perhaps before I do that I have a spare 130 air correction jet (it's currently running a 125) that should lean it out at the higher revs shouldn't it?

Regards Kevin

Yes. If that's where you were rich, then try it.

Jan