Page 1 of 2 1 2 LastLast
Results 1 to 10 of 13
  1. #1

    Join Date
    Aug 2014
    Location
    Jackson, Tn
    Posts
    35

    New engine start-up

    What do I need to do to initialy to start a newly installed rebuild. I have redone the carbs, also.


  2. #2
    CJ's gpr's Avatar
    Join Date
    Aug 2012
    Location
    Long Island
    Posts
    685
    +1
    34
    Depends on the specific engine. SBT has a good write up on breaking in a rebuild. Usually run a richer oil mixture and don't run at WOT for long periods of time.

    http://www.shopsbt.com/forum/technic...ew-engine.html

  3. #3

    Join Date
    Sep 2006
    Location
    Houston Texas
    Posts
    364
    +1
    10
    If auto oil injection bleed the lines, if premix ratio should be rich, about 32/1 or even 24/1 fresh gas is must in both cases. If you have primer 3 or 4 squirts should get it fired repeat until motor fires. If choke is installed ,I have that a squirt bottle filled with premix gas will save the battery. If three is a flush fitting make sure the motor stays running before turning on the water. For the first couple of starts, keep checking for fuel leaks. As the motor breaks in, will be easier to start. This is what I do on race Pro 785's. I'm sure the guys with more knowledge will chime in.

  4. #4
    This is how I run a jetski shop in the desert nmpeter's Avatar
    Join Date
    May 2008
    Location
    Elephant Butte New Mexico
    Posts
    6,528
    +1
    1,274
    it's preferable to feed the water front the actual pump line not the flush fitting for a Polaris unless you have the opportunity to start it up in water.

    I always do my initial starts in the water tank, so I don't have to dick around with the water line from the pump.

    However keep in mind that some engines get a bit warm when running from a flush fitting, as the water is running backwards thru the engine.

    Use only premix to prime an engine, you vitally need that upper cylinder lube, for the first few seconds of run time.

    watch with great care for water leaks

    stop the engine and read the spark plugs after the first few minutes

    follow advice on break in supplied by SBT..they do not want their motor coming back for a free replacement!

    I start off a new engine with a five minute run, then a rest..then another five minutes..then a rest..then ten minutes and so on...

    I want the engine to have as long a life as possible, and I have the luxury to do so because I'm getting paid for it..so I do what some would consider overkill.

    Fresh fuel is a must..don't even think about using the stuff that was in the tank before you installed this new engine.

  5. #5

    Join Date
    Sep 2006
    Location
    Houston Texas
    Posts
    364
    +1
    10
    Captain ( Pete ),
    Could you explain how to feed the from the pump line ? And thanks for the info !!

  6. #6
    bowsniper's Avatar
    Join Date
    Aug 2008
    Location
    macomb,michigan
    Posts
    5,896
    +1
    6
    Go 32;1. After first tank go 40;1. . Use fresh plugs. Let it watm up in water and. Check for leaks first. Then put hand on jugs as it watms up. It shouldnt get so hot you cant keep a hand on them for a few seconds. Then run it gently going thru the throttle. Keep off going wot for a tankful. Check the piston wash after the first tank. Always run it rich on the low speed and high speed needles. They can be dialed in tighter after you see the wash. Then run it like ya stole it. Keep watching for leaks of fuel and water.. it should.start almost instantly if running correctly. Have fun.

  7. #7
    This is how I run a jetski shop in the desert nmpeter's Avatar
    Join Date
    May 2008
    Location
    Elephant Butte New Mexico
    Posts
    6,528
    +1
    1,274
    the water feed line from the jetpump is what you want. You can use a threaded garden hose barb to hook up to it. This allows water flow thru the engine exactly as it would be during in water running.

    Flush fittings flow in reverse, that's the point for their presence. Some engines will not get optimum cooling when run this way

    On some skis the lines can be hard to get to.

    Weigh the hassle of getting to the boat ramp..might be easier...

  8. #8
    ilovemyskidoo's Avatar
    Join Date
    Jun 2014
    Location
    Wayland ny
    Posts
    95
    +1
    1
    Adding extra oil to the tank imho is not a good idea. I've never done this and never really understand why people do this. More oil in the gas equals less fuel meaning Your motor will run hotter.

    the other misconception is when You say a oil ratio of 20-1 or 40-1 most people think that 20-1 is richer than 40-1 when in fact it's the other way around. it's parts of oil to gas so 20 parts oil to 1 part gas or 40 parts oil to 1 part gas. this might sound stupid to some but You would be surprised how many don't know this.

    I have always lived by the rule of You break in a motor just how You normally ride it. I have rebuilt many motors and have never added oil and I sure as heck don't baby it. Just get on it and ride it. and I don't say this for no reason with no experience. the first 20-40 minutes of a fresh rebuild or even a new motor are where the rings and cylinders are going to take a set. once the filing on the rings and cylinder wall is gone Your done with the "setting" so it's important to get that motor revving so that all the microscopic imperfections get filed away. this will result in better compression better oiling more power and a longer motor life.

    This is just My opinion based on My experiences I by no means am saying this is the rite way, but it has worked for Me.

  9. #9
    Click avatar for tech links/info, donation request K447's Avatar
    Join Date
    Jul 2007
    Location
    near Toronto, Canada
    Posts
    36,591
    +1
    1,275
    Quote Originally Posted by ilovemyskidoo View Post
    ... when You say a oil ratio of 20-1 or 40-1 most people think that 20-1 is richer than 40-1 when in fact it's the other way around. it's parts of oil to gas so 20 parts oil to 1 part gas or 40 parts oil to 1 part gas. this might sound stupid ...
    40:1 does indeed mean 40 units of gasoline with one unit of oil dissolved in that gasoline. The engine consumes large quantities of gasoline and small quantities of oil.

    20:1 would mean 2 units of oil disolved in 40 units of gasoline, which is twice the oil density in the fuel compared to 40:1

    I tend to reserve the terms rich and lean to discussions about air to fuel ratios, not for oil to fuel ratios.

    Adding oil to the fuel tank on an oil injected carburetor engine will displace some gasoline as the oil+gasoline mixture flows through the carburetor. Sometimes on a fresh engine break-in the carburetors are set somewhat richer than normal to ensure the engine is operating far away from the edge of lean burn. So effect of the extra oil in the fuel is compensated for by the richer carb settings until the break-in process is complete.

    Engine break-in is all about friction, heat and pressure. The freshly honed cylinder walls cause extra friction against the piston rings. That friction, combined with the pressure of combustion gases behind the rings, causes localized wear to 'bed in' the rings.

    That extra friction also causes more heat. The recommended break-in routine includes cool down periods that use the heat cycling to help the piston and rings conform to the cylinders. As the break-in procedure progresses the extra friction from honing roughness is reduced and it takes more pressure in the combustion chamber to continue the ring wearing process.

    This is why the recommended break-in process includes increasing amounts of time at higher throttle levels as the engine break-in proceeds. Eventually the final stages of break-in include durations of wide open throttle, creating maximum pressure behind the piston rings and forcing the last bits of ring to cylinder wear to complete.
    Last edited by K447; 11-01-2014 at 04:45 PM.

  10. #10
    bowsniper's Avatar
    Join Date
    Aug 2008
    Location
    macomb,michigan
    Posts
    5,896
    +1
    6
    We never broke in the new honda accords i use to sell. Just get it n punch it. Lol. Ran great. Jus sayin.....

Page 1 of 2 1 2 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. found a "new" 98' STX 900, start-up question
    By TJBrad04 in forum Kawasaki Open Discussion
    Replies: 3
    Last Post: 04-22-2009, 08:55 PM
  2. new throttle, now it redlines at start up?
    By sfackett0 in forum 4-Tec Performance
    Replies: 5
    Last Post: 03-29-2009, 05:42 PM
  3. New engine no start...
    By 240witSR in forum 2-Stroke Performance
    Replies: 62
    Last Post: 07-29-2008, 07:18 AM
  4. 97Xp new rebuild engine starting Problem
    By ruinplay in forum 2-Stroke Performance
    Replies: 4
    Last Post: 08-16-2007, 09:26 PM
  5. Engine Break In/first Start Up?????
    By RDH in forum Yamaha How To & FAQs
    Replies: 24
    Last Post: 05-03-2007, 01:24 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •