crash bandit Posted January 23, 2006 Report Share Posted January 23, 2006 I'm having my txt 270 cylinder replated and fitting a new piston, rings and little end bearing. What is the best method to run the motor in? Quote Link to comment Share on other sites More sharing options...
north_yorkshire_lad Posted January 23, 2006 Report Share Posted January 23, 2006 spend 2-3 hours just on 1/4 throttle and then gradually build up to when you can attempt large revs etc. we were told that it's a better idea to keep the engine reving rarther leaving it on't tick over Quote Link to comment Share on other sites More sharing options...
magicmat Posted January 23, 2006 Report Share Posted January 23, 2006 there seems to be a widespread opinon, its best not to leave it ticking over as said above, unless your bedding in cams in a car engine, where you need to, i just got this off the erik gorr website, (recently shown to me seems to know his stuff) http://www.ericgorr.com/twostktech/twotopw....html#10%20TIPS 10) When you initially start the engine after a rebuild, manipulate the choke to keep the engine rpm relatively low. Once the engine is warm enough to take it off choke, drive the vehicle around on flat hard ground. Keep it under 2/3 throttle for the first 30 minutes. Two common myths for proper engine break-in are; 1) Set the engine at a fast idle, stationary on a stand. 2) Add extra pre-mix oil to the fuel. When the engine is on a stand it doesn't have any air passing through the radiator and it is in danger of running too hot. When you add extra oil to the fuel you are effectively leaning the carb jetting. This can make the engine run hotter and seize. ive also heard that you should run the engine for 5mins x 3 10mins x3 15mins x 3 allowing it to completely cool, and dropping the oil. from these, i would say thats its best to drive the bike around as said by ERIC and NOT LABOUR the engine, (making it work to do hills and stuff) that should do you,....im also researching this and engine building as im rebuilding an engine,..(see other topic) Have fun Quote Link to comment Share on other sites More sharing options...
gasgas Posted January 24, 2006 Report Share Posted January 24, 2006 With a replated cilinder and new piston plus rings the only thing that shld be done is give the piston a few heat cycles. It seems that a new piston expands new differently(faster) as when it is older. Something to do with "molecules". I am not a metallurgisch guy so maybe somebody with knowledge can jump in here. The heat cycles are there to give this piston a few chances to expand and contract again. Further there is nothing to it. Rings are settled in a new cilinder after about 10 hours(i have this info from a man who replated my cilinders and is working for GP teams in sidecross) A new plated cilinder takes even more time to settle. So, it is safe to say that yr motor is up to parr after about 10 hours of riding. That doesn't mean you have to take it slow after the heat cycles, only that yr engine becomes better after 10 hours.... Quote Link to comment Share on other sites More sharing options...
crash bandit Posted January 24, 2006 Author Report Share Posted January 24, 2006 Thanks chaps, certainly plenty to consider. I once owned one of those Honda Pilot buggies and had alot of engine seizures with that. I would have the cylinder bored and new piston etc. but it would seize quite quickly. The only method that seemed to work was to run the engine until hot then let it cool completely ( as stated above ) and repeat this 3 - 4 times. Then drive it carefully for a short period gradually building the revs. This method worked with the pilot but I don't think that had a plated bore. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.