Bonneville America Forums Forums Technical Forums Performance Mods Dealer Big Bore Install

So I rolled down to Atlanta Triumph over lunch to find out about doing the big-bore install for me. Without details they quoted me about $875 total labor for the Big Bore install. That's 7 hours to break the bike down and put it back together, $200 to ship the jugs out and have them machined, and all re-jetting and carb balancing. Does not include the Bore kit, which is $499. So basically $1,400 to add 109 CC's to my bike.

So the question is, can a moderately technical guy break the bike down, get the jugs machined and sleeves installed, and put the bike back together and running and save $600?

Leaning towards the dealer install, but $875 is the exact price of the Thunderbike Cams....

If you have the knowledge to break a motor down, keep everything straight, and put it back together again, I don't see why you cannot do it yourself.

This is what I plan to do (BB, cams, and carbs) once I save up the required funds. Of course, I will do them one at a time!

Absolutely! It really isn't that hard. If you're a semi-decent mechanical type person you should have no problem doing it yourself. heck, if'n I can do one, so can you.
Big Bore Directions

Alright Guys, you sold me on it. It will feel all the better having done it myself, and then I can honestly look at the Thunderbike 790 cams when they're ready. Figure $200 tops for the machine work!

Just ordered the Haynes manual from the UK, see general discussion forum, so maybe that will help. Although I wonder about any special tools I'll need?

Okay, scratch that. Just looked at the instruction page and heed the warning of possible killing my motor by pulling cams out wrong.

Great instructions, but I know me and I know I'll blow up the motor!

Ummm, if you take your time with those T30 Torx bolts on the cam bearing caps, removing your cams is really no challenge. Use the service manual and obey the timing marks!

As long as you line the cams back up properly it is not hard. You just need to follow the directions and using the manual you can do it. However, if you don't feel you can do it, then by all means pay someone that can to do it for you. Peace of mind is invaluable.

You can do it mate, I am just about complete with mine and I'm only an electricion! This was my first engine re-build and couldn't believe how simple it was. All the timing marks make it a game of dot to dot, just remember to take your time and read dinqua's tips and the manual before you do anything.

The money you save on the labor you can spend on the head, match port / port job and valve grind etc (just posted a picture of mine).

Just give it a go, if your not sure of anything just ask a mechanic to drop around and help you out - free beer after!

Back in the when, I decided to do the same thing to a KZ1100D2 Spectre, code name 'Beetlejuice'. Armed with a Haynes shop manual I tried my first 'strip to the cases'. It took 2 days. The thing that helped most, besides 3 languages worth of swear words, were the Polaroids I took during the disassembly. It turned out the Haynes had the coil leads labled backwards, and the pictures showed the right way. Today I would suggest taking detailed video of the disassembly. Keep the shims and buckets in separate, labeled containers (I used ziplock bags). Good luck!

BrianT, Pat (Dinqua) has already taken the photos of his rebuild and logged every step on this site and his own personal site. I also believe that BikerT has done the same to include replacing the clutch plates........Angelis

That's good as a general guide but there is no way I am tearing my engine down without taking detailed photos and video of every step.

Man, it just scares the bejesus out of me. I'm relatively competitent with stuff, but..I'll put it this way. It would probably be easier for me to make $800 than to do this right. Once the manual get's here I'll really take a look. I'm going to talk with a few other shops and see. The fact that it's not that tough of a job (for someone who know's their way around an engine) makes me think I could get it a little cheaper. The scariest part is doing it alone!