Engine revs rising when air lever opened

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GaryK
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Re: Engine revs rising when air lever opened

Postby GaryK » Thu Jun 06, 2019 1:50 pm

Hi James

I have not spent much time working on the bike as other things always seem to crop up.

Just recently I checked the timing which was a little out, and I have re-timed it, but still not running correctly.

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alan.moore
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Re: Engine revs rising when air lever opened

Postby alan.moore » Thu Jun 06, 2019 3:01 pm

James,
You haven't mentioned whether you have made sure there is no leak between the carb and the intake flange on the cylinder head. It is not uncommon for the alloy carb flange to get a warp in it causing air to be sucked in at the joint. This will give the symptoms you describe.

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Alan
1939 VH Redhunter;1942 RN WNG;1951 Triumph 6T Thunderbird;1970 BSA B175 Bantam;1986 Yamaha SRX600 single
http://cloggymoore.wix.com/triumph-pre-unit-6t

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James Hickman
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Re: Engine revs rising when air lever opened

Postby James Hickman » Thu Jun 06, 2019 7:06 pm

Yes I have - but will replace the gasket anyway. However I still need to decide what to do about the cylinder head leak...

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Re: Engine revs rising when air lever opened

Postby dave.owen » Fri Jun 07, 2019 6:13 am

Have you checked for wear on the inlet guide, could give similar results
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GaryK
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Re: Engine revs rising when air lever opened

Postby GaryK » Thu Sep 19, 2019 7:43 pm

Hi all
Finally got round removing the alloy head as there was defiinately a leak between barrel and head.
After removing the oil feel to the rockers I noticed that only the exhaust rocker spindle has a hole in the end where the banjo attaches. See photo. Surely the inlet rocker should have a hole or how is it lubricated?
20190919_192430.jpg

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Re: Engine revs rising when air lever opened

Postby GaryK » Sat Sep 21, 2019 5:12 pm

Do you think i need to drill a hole in the inlet spindle shaft the same size?

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Re: Engine revs rising when air lever opened

Postby admin » Sat Sep 21, 2019 8:54 pm

Image

It's the same part for each side ...
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GaryK
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Re: Engine revs rising when air lever opened

Postby GaryK » Sun Sep 22, 2019 9:56 am

Thanks John
Yes I have looked at that diagram but it's not detailed enough to see the hole in the spindle. I assume both shafts must have a hole to be able to get the oil in.
A copper gasket has been fitted on the barrel to head joint. I don't think a gasket should be fitted with an alloy head so that might be my problem with the head leak.

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Re: Engine revs rising when air lever opened

Postby alan.moore » Sun Sep 22, 2019 7:21 pm

Gary,
Yes both shafts should have the oil hole for the banjo and a second further along the shaft to oil the rocker arm. Look on the drags website here:
https://www.draganfly.co.uk/triumph-sho ... _pathway-2 (click on the photo to enlarge it)

I cannot understand how the inlet rocker assembly, fitted with the spindle you say has NO oil feed hole, could have been operating without seizing if its not being lubricated. Are you sure the hole is not just full of gunk?

I think the shafts are hardened so you may have problems drilling it accurately/ easily. I would think someone on the forum will have a spare you can purchase if you need to.

Looking at the diagram above and the parts list no mention of a head gasket. I think there are a few '57 VH owners on the forum, hopefully they will chip in with advise on how to cure your head leak

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Alan
1939 VH Redhunter;1942 RN WNG;1951 Triumph 6T Thunderbird;1970 BSA B175 Bantam;1986 Yamaha SRX600 single
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Re: Engine revs rising when air lever opened

Postby paul.jameson » Sun Sep 22, 2019 9:39 pm

There should not be a gasket between alloy head and cylinder on a single. The head to cylinder joint seals on the top of the cylinder flange and there is a small gap round the outside of this.
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