Hobbit compression woes & cylinder bolts that won't torque down

Jessie Paull /

I just finished putting my the top end of my engine back together, and to my dismay my poor Hobbit no longer starts. It seems to be a lack of compression.

I had just had my cylinder off and replaced my piston rings, and when I put it back on I torqued the bolts down to 7ft/lb (manual said between 5.6 and 8.7) Thinking maybe the bolts needed a little more torque, I set my wrench to 8ft/lb and started turning each one down in a star pattern.

3 out of 4 bolts clicked, but the top right bolt just kept going. After a couple cranks I start getting nervous - maybe I'm gun shy bc I just broke a bolt off (other side) a few weeks ago and it was agonizing getting it out - so I pull the bolt out to look at it.

In the attached picture #1 is a spare bolt I had laying around, #2 is the bolt I just took out, and #3 is the second bolt I tried next.

To me bolt #2 looks a little fucked up, like the threads were stretching out and it was about to snap. So I take another spare bolt and start torquing down, but that seems like I've turned my wrench way too many times too and so I take that one out too (#3)

Am I crazy? Should I just trust the torque wrench, or is it possible something is wrong with the hole in the case? I'm wondering if this might be the issue with my compression. (edited)

IMG_20200728_195224~2.jpg

Re: Hobbit compression woes & cylinder bolts that won't torque down

Get new bolts or even better get studs then try it.

Re: Hobbit compression woes & cylinder bolts that won't torque down

Replace all of them . 2&3 are very close to breaking and 1 likely isn't far behind .

Re: Hobbit compression woes & cylinder bolts that won't torque down

FYI Puch cylinder studs, washers and nuts work perfectly on hobbits.

Re: Hobbit compression woes & cylinder bolts that won't torque down

Stock head?

Re: Hobbit compression woes & cylinder bolts that won't torque down

Jessie Paull /

Awesome, thanks guys. Glad I didn't keep cranking them down now. I'll definitely check into swapping for studs.

Re: Hobbit compression woes & cylinder bolts that won't torque down

Jessie Paull /

> Happy Pancake Wrote:

> -------------------------------------------------------

> Stock head?

Yep

Re: Hobbit compression woes & cylinder bolts that won't torque down

Jessie Paull /

> Stephen Simmons Wrote:

> -------------------------------------------------------

> FYI Puch cylinder studs, washers and nuts work perfectly on hobbits.

Stock bolts are M6 100mm looks like the Puch studs are M6 106mm 👌

Re: Hobbit compression woes & cylinder bolts that won't torque down

> Jessie Paull Wrote:

> -------------------------------------------------------

> > Stephen Simmons Wrote:

>

> > -------------------------------------------------------

>

> > FYI Puch cylinder studs, washers and nuts work perfectly on hobbits.

>

> Stock bolts are M6 100mm looks like the Puch studs are M6 106mm 👌

YEP. I used them on my Hobbit with stock head and they worked perfectly.

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