Can't seem to remove the rocker pivots from my SR250 - Help please?

I need to strip the head to have is aqaublasted, but I can't seem to move them. I have tried to use a 6mm bolt and pulled the pivots, but they seem pretty tight.

Will a little heat help? or is it a case of a slide hammer fabricated with a 6mm thread to go into the pivot?


any help will be really appreciated

Ta

Dave

vortexracing said:

I need to strip the head to have is aqaublasted, but I can't seem to move them. I have tried to use a 6mm bolt and pulled the pivots, but they seem pretty tight.

Will a little heat help? or is it a case of a slide hammer fabricated with a 6mm thread to go into the pivot?


any help will be really appreciated

Ta

Dave

Click to expand...

Should slide right off after removing the pivot shaft:

Heat should help, as the aluminum should expand more than the steel shaft. Might just be seized in there - is there any play? Is the rocker free on the shaft, or does the shaft itself rotate when the rocker moves?

If you thread the bolt into the end of the shaft all the way and turn it, does the shaft rotate?

Finally - is part #11 in the diagram above perhaps a circlip or a clip like on the ends of a piston wrist pin? I assume not, but doesn't hurt to ask.

There both steel on that bugger, might have worn a slight shoulder on the shaft... make sure the circlip is out, ren the bolt in and grab it lightly with vise grip and tap the vise grip to see if it will come free.

Cheers guys, firstly there is no circlip as far as I can see, only an o ring which from the diagram looks like it around the pivot pin.

Just tried a the other one , I.e. the one held in place by the tab washer and that is the same, stuck well and truly.

I even tried using a spacer held between the bolt head and the inside of the cylinder head to see it I could draw it out but it's not moving.

The rockers are free to move and have some slight side to side movement, When I insert the 6mm bolt the pivot pin stay stuck and does not rotate.

I'll try some heat tomorrow and let you know what that turns out like. I may end up leaving it and see if he can blast it carefully with the cam and rocker covers in place and try and find a way of covering the cam chain hole up so no crap gets in that way. The valves are closed so nothing should get into the ports via those.

a couple of piccies to help me explain.

http://20150221_175321 by eastham_david, on Flickr


and one of the offending pivot pins

http://20150221_175326 by eastham_david, on Flickr

thanks

Dave

If it won't turn you should be able to heat it, i was thinking it was stuck on the rocker... heat it up with some pressure against it using the bolt and a bushing of sorts like you were should pop loose.

i put a bolt with the head hex ground round into my slide hammer (smallone lol)

then thread the threads of the bolt into the pin and a few taps and out they come it is probably hung up on the rock hard oring

Sorted !!!

Thanks guys, has a good think over a couple of beers last night, and decided to have a go at making a pulley. I don't have a small slide hammer.

3mm thick steel strip with a 6mm hole in it and 4 different lengths of 6mm bolts and they both came out easily in the end.

Didn't even need to heat them up

20150222_163029 by eastham_david, on Flickr

My next thought was about the cam ???

But a quick pull and wiggle and the whole lot came out. It only left the roller bearing in the far end.

20150222_165013 by eastham_david, on Flickr

I'll pop into the aquablasters this week and see if he thinks that will be OK left in, I don't fancy trying to get that out

I suppose I could always try and mask it in some way, just to keep the abrasive stuff out as much as possible.

Has anybody removed that inset bearing and re-fitted one, if so how did you do it.?

Anyway, all out and ready to go except that bearing and I need to find somebody with a small spring compressor then the Valves can come out.

20150222_165033 by eastham_david, on Flickr

Here is the offending stud that needs a clean and re-weld, then tapping, the previous owner must have known it was blowing, the whole area is black around the exhaust port.

20150222_164940 by eastham_david, on Flickr

Head and Piston/barrel look good, the motor looks like it's in really good condition, apart from that stud. :

20150222_164946 by eastham_david, on Flickr

20150222_165001 by eastham_david, on Flickr


Lastly, I'm assuming those pivot pins will need new o rings? am I correct?


Thanks for your help guys, it's really appreciated.


Dave

Stud aside things look good, should be good as new with that built up with a fresh weld, drill and re tap... Nice work!

I certainly hope so, fingers crossed

The motor looks good for the year and mileage

anybody tried to remove the cam bearing?

or do you think I should just leave it in?

i would leave it unless you have the install tool and a new one on hand