Any done this?

Hi all,well after getting my head rebuilt with new guids oil seals ss inlet valves,and valve seats cut,i went and slung it back on the motor.After slideing the rod the exhaust rocker sits on, i snapped that hex bolt that you take out to get the exhaust rocker rod thingy in/out:bonk:So then found another bolt that went straight in.Anyway kicked it over and checked it over once running.Thought was def alittle harder to kick but really no biggy.But after taking the rocker cover off found the bolt i put in the head was to long and the decomp weight on the cam hit the bolt and snapped off:banghead:, luckly sat with the spring in the corner of the head:worthy:Do you guys think as over hear they want £75 prob $150 just for the decomp weight,i could run without it as it wasnt that much harder to start.Or do you think there is some kind if balance issue without the decomp weight.Cheers all


I'm not really sure what you are trying to say.... There isn't a bolt that holds the exhaust rocker in...its a smooth shaft that just pushes out. I'm not sure what bolt you broke. In fact, it sounds like you didn't remove the threads of the broken bolt and somehow put another one in on top of that bolt? And then something about a bolt hitting the decompressor weight which I don't understand. What bolt did you put in that was too long to snap the decompressor bolt and why did you do this?

I suggest that you explain your problem in a little more detail while using the correct terminology of the bolts and other parts. A picture with some arrows pointing to the trouble spots might help too. I think the reason you are not getting any help is that no one can really understand what you did.

I read this again and again and still don't understand it exactly. The only thing that needs to be removed to get the rocker shaft out is the cap that is screwed into the head. Once you remove the cap, you can easily slide the rocker shaft out and then remove the rocker. There is no "bolt" that is holding the rocker shaft in, thus no bolt to get the "rocker shaft ?thingy? in/out".

But apparently you broke some kind of bolt but I'm not sure what bolt that was...and did you get the threaded portion of that bolt out? I'm not sure...but you found another bolt (which concerns me) and decided that was okay to use. Where did you happen to find this "bolt"? The hardware store?!? Anyway, later in the story you note that it was head bolt? You mean one of the bolts used to bolt the head to the engine block? You broke one of those and replaced it? And it was too long? I still don't understand what bolt.

So, then it sounds like the camshaft was clear of everything until you kicked it hard and the decompressor weight swung out and hit this new bolt that was too long, whatever bolt that was. Then you sheared off the decompressor bolt and you were "lucky" enough that spring was still in the corner instead of down in the crankcase. Did the bolt snap? You made it sound like this bolt snapped too. But then why do you need to buy the decompressor weight? Or did the decompressor snap and the bolt is okay? Where were those pieces lying? If they snapped, are thee fragments of metal now in the head? Did anything get in the crankcase?

Now you're ultimate question is can you run the engine without the decompressor. My "guess" is no. The camshaft is balanced and by not having a part in the cam, it would throw off the balance. All I can say is you are very lucky. My advice is buy the correct replacement parts: correct head bolt, new decompressor spring, and if needed, a new decompressor bolt and decompressor weight. Put the correct parts in and torque them to spec with a torque wrench....and HOPE that you didn't do any more damage than you did.

Ok bud ill try again, When you take out the exhaust rocker out,first you take out the hex bolt on the side of the head.Then slide out the rod/shaft that holds the rocker in place.Naw that first hex bolt you take out the side of the head is one i snapped.I then replaced with one that was to long,with the thread popping through the head when the camshaft made a rotation the decomp weight hit the thread and snapped. If you read first post again then look at a bike it all becomes clear lol.When i started the bike for the first time after the head rebuild i dident find the bike to hard to start.And did start and shut off the bike a few times and found it ok.But without the decomp weight and use of the decomp at all do you guys think the camshaft would be out of balance?Parts are just so expensive at the mo just thought if i found it ok to start and its safe to do so then i wont bother buying the new decomp weight.cheers lee

I understood him first time when i read it earlier but being a fellow brit i just thought.........

what a knob :prof:

speedy........ I would have thought that as long as you are happy without the weight doing its stuff you might be better removing the arm that slides inside the cam and the bolt and retaining plate so nothing else can come loose in there. Just get used to the old method of starting a HC 4 stroke motor

Push kickstarter to TDC with compression, push a small amount (it will be hard) until it just goes 'over the top', release the kickstart and give it a full kick and .............

hope it doesn't kick you back :smirk:

Oh.... and..........

change your username to 'strong right leg' :smirk:

Spoken like a true brit lol

Well thats what i thought just wanted some other thoughts from people that no the bike.Gonna have a search around for some people breaking a bike and go from there me thinks.Mr strong right wrist i mean right leg out.

I couldnt figure out what you were talking about either at first, but your talking about the plug on the side of the head. It broke and you put a bolt back in that was too long that caused the decompressor to break.

I doubt it would be a good idea to run the engine without a decompressor but Ive never tried it.

I couldnt figure out what you were talking about either at first, but your talking about the plug on the side of the head. It broke and you put a bolt back in that was too long that caused the decompressor to break.

LOL...thanks, now I understand too. A "bolt" and a "cap" (plug) are two totally different things. :smirk:

LOL...thanks, now I understand too. A "bolt" and a "cap" (plug) are two totally different things. :smirk:

Over the other side of the pond old boy it makes perfect sense:moon:

Cap sounds like a peice of plastic covering a hole.And as this has a thread and a hex head its a bolt over hear:p

I guess so! It's probably best to use the fiche on thumpertalks parts database...then there is only one name for each this instance, its says "cap".

lol ur prob right:thumbsup:

Well after all that i went and bought a new decomp weight at £74 deliverd from honda uk.Had a think and just thought after a complete rebuild top and bottom with new ss valves id be a plonker to risk it:bonk:.Cut the bolt/cap/plug/goggle pin back ready for the new weight install.Whaddon on the 5 june for all you brits,get youself down there:thumbsup:

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