Just replaced head. Pushrod length question.

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worstdayever

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Oct 17, 2016
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Parked my 750 commando a couple months ago and had the head sent out to jim to have the exhaust ports milled. Got it back and installed it the other day. I just read something about 2 pushrods being longer than the other 2. Is this correct? I could swear they were all the same length.


Thank you
 
lol that's so newbie a question to respond to as real question is which length pushrod pair are attempted to shove in first. Intake valves/rockers/lobes are closer together than splayed out exhaust side, if that helps.
 
hobot said:
lol that's so newbie a question to respond to as real question is which length pushrod pair are attempted to shove in first. Intake valves/rockers/lobes are closer together than splayed out exhaust side, if that helps.
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Thank you for once again proving british bike owners are some of the most elitist, condescending pricks to walk the earth. I had a feeling id run into someone like you on this post. I held out hope that it wouldnt be the very first reply though. I shouldve known better. I hate coming here to ask questions.
 
worstdayever said:
Thank you for once again proving british bike owners are some of the most elitist, condescending pricks to walk the earth. I had a feeling id run into someone like you on this post. I held out hope that it wouldnt be the very first reply though. I shouldve known better. I hate coming here to ask questions.
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There really aren't that many elitists but unfortunately they do seem to be the most vocal.
 
There is an ignore feature so you never have to see selected members posts, go to your user panel and add the members names to the for list, their posts will disappear.
 
Manual got push rod placement correct so why tempt resident ass hole like me with such a lazy ass question. Those offended can answer what's not in the manual on which length must go in first and why. Will not intrude again as not seeking angery offering realistic help.
 
19,000 posts of some jibberish language and fantasy. Pay no mind.
 
Thank you everyone for your replies. Todays been a rough one. I just got the bike all buttoned up lastnight, before finding out about the pushrods today. Now it gets to come apart again. My fault, i know, but it still sucks.
 
Hang on a mo, have I missed something (again)?

Why do you need to remove the head?

From my recollections of fitting my Cdo head (I’m no expert, I’ve done it twice) I didn’t think it was possible to put the pushrods in the wrong places? Surely it wouldn’t be possible to locate them?

Can’t you remove the rocker covers and turn the engine over slowly by hand? You’ll be able to see the rockers and valves moving if all is correct.
 
Fast Eddie said:
Hang on a mo, have I missed something (again)?

Why do you need to remove the head?

From my recollections of fitting my Cdo head (I’m no expert, I’ve done it twice) I didn’t think it was possible to put the pushrods in the wrong places? Surely it wouldn’t be possible to locate them?

Can’t you remove the rocker covers and turn the engine over slowly by hand? You’ll be able to see the rockers and valves moving if all is correct.
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Im going to go pull of the rocker covers and take a look. Im sure i didnt notice any length difference in the pushrods when i had them out. I just grabbed 2 and put them in each side. I thought i made all my bonehead mistakes on my triumph. Apparently i saved a few for the norton. Thanks
 
These aren’t standard pushrods, but still show the length issue. There is a big difference. If you did manage to put a long one in place of a short one, I think you may have forced a valve so far open to have contacted the piston and bent it.
So I hope not.
It would have been very difficult to make the rocker ends line up too.
Anyway, fingers crossed for you!



Just replaced head. Pushrod length question.
 
Ugh, that's exactly what made me so Commando obnoxious - learning the hard way, no one warned me about hang ups not in the manual. Note - be alert to a short/sharp cliink on clamping down head as implies push rod jumped track so back in again to make sure or else... After a while as post counting Jim C says - ya'll see who to ignore or tease.
 

Firmly hold head up with one hand while other fingers fumbles push rods - ugh - I put head oil banjo bolts in to zip tie head at good height to diddle rods into head, with both hands, if not already done on bench, then clip ties to lower in hopes all is well. Zip ties, rubber bands to stuffed rags can hold p-rods jammed up in head.

SECTION C8 REFITTING ROCKERS

1 Place the cylinder head gasket in position on top of the cylinder.

2 Turn the engine until the pistons are at top dead centre so that there is minimum valve lift and on assembly one pair of pushrods is fractionally higher than the other.

3 Place the pushrods in the pushrod tunnels in the cylinder head with the inlet pushrods (that is the longer pair) inboard and the shorter exhaust ones, outboard. The cupped end of each pushrod is uppermost.

4 Take the cylinder head firmly in one hand and feed the pushrods as far into the cylinder bead as possible, holding them with the other hand. See Fig. C3.

5 Place the cylinder head over the cylinder, forward end downwards and allow the pushrods to drop down the cylinder barrel pushrod tunnels. Note that the pushrods cannot do other than locate on the cam followers at the lower end.

(ugh Note, can settle on top of lifter rim socket- not seated underacted til later)

6 *Starting* with the pair of pushrods which are slightly higher, engage the tops of the pushrods to the rocker ball ends as the cylinder head is lowered. Use an implement such as a thin screwdriver through the exhaust rocker box to guide the pushrods into position as shown in Fig. C8. Having engaged the first pair of pushrods engage the second pair in a similar manner.

The cylinder head is ready to be secured...
 
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Fast Eddie said:
These aren’t standard pushrods, but still show the length issue. There is a big difference. If you did manage to put a long one in place of a short one, I think you may have forced a valve so far open to have contacted the piston and bent it.
So I hope not.
It would have been very difficult to make the rocker ends line up too.
Anyway, fingers crossed for you!



View attachment 4724
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When they were out, i swear there was no difference. When i placed them back in, it looked like your picture.
 
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