Re-Jetting Query

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moggyman64

Re: Re-Jetting Query

Post by moggyman64 »

Hi All,

Update

I did a compression test with engine warm and WOT, cyclinders 1,2 and 3 were 172 PSI and 4 was 170 PSI. Which is approx 12 bar.

I have been checking the valve clearance ( cold engine) with the lobes perpendicular to the buckets/shims, the feeler gauge passed between with just the slightest of gripping feeling and I have discovered the following:

Haynes states Inlet clearance as 0.018 in, (0.45mm) and mine measured correct.

Exhaust clearance Haynes states 0.024 in. (0.60mm) but I have clearance measurements of:
Clearance measured for cyclinders #1, 2 and 3 is 0.019 in. (0.48mm) and #4 is 0.016 in. (0.40mm)
As you can see there is quite a discrepency to the specification. I have just been looking at the Haynes manual again and there are two sets of listings on the page for valve clearance. Now I totally confused.
It reads as follows;
Valve Timing (valve clearances set at 0.031 in (0.8mm) and underneath it lists the inlet and exhaust opening and closing degrees. But at the bottom of the page it lists Valve clearances ( engine cold) and lists the dimensions for
Inlet ... 0.018 in (0.45mm)
Exhaust ..... 0.024 in (0.60mm)

Now I am starting to get a bald spot from scratching my head. Hymmm

The head was overhauled by someone else and find it hard to understand how he could fit shims that are so far out.
Advice please for what I need to do to get the clearance back to within spec. I have not done any shim etc. work before so some guidance would be appreciated.

Could this be causing the problem of lack of power as mentioned earlier in the thread?

Regards

keith
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