G'day, I have a Masport mower here that's only a few years old and has had very little use..
The problem I have is its over revving. Now it does this even with no governor spring attached...at this stage I am wondering if it could be an internal problem with the governor? I can bring the revs down my holding the butterfly..but without holding it the engine just pulls it on full ball..
I also removed governor arm to try and fault find and I am now unsure of position it should be refitted..
I have tried to get a service manual for this engine which has left me frustrated..I am sure you guys will know whats going on, would appreciate any help thanks
If governor spring is removed, should the governor arm spring back by its self? My engine is a later model than the one in the Video..the Governor arm is horizontal at the back of the engine, it has a keyed spline..
same as the video S.D put up really . loosen the nut on governor lever ,turn gov' shaft clockwise to full travel and tighten nut . throttle must be wide open . then check throttle can be moved from idle to wide open without feeling tight or binding .
and when its setup . where the governor spring connects to the throttle plate end , the pear shaped tab there ? it can be bent gently to adjust revs . slightly bend it back towards carby side of movement , then when its up and running gently bend forwards to adjust full revs , then back to idle see if it does it well too but dont ask too much from full revs or it will 'hunt'= rev up and down . bouncing off of the governor . just set it to idle nicely and not too high at full revs should be allgood
Yes I have done all this...when the engine is running, tightening the governor spring makes no difference because there is no resistance..the only way i can bring the revs down is by pulling the governor arm back by hand, this is why I am asking is there something mechanical internally that can go wrong with the governor?
no not normally but stranger things have happened . other than pulling it down for a looksee just check it all again to be sure . not the carb bellcrank is sticking ? some do if working in really dusty conditions . or something bent or binding , recheck if its touching the top coweling somewhere you should feel or hear it if it is . they are easy to bend and all it takes is a small twig to hit the right spot
No, nothing is stuck...the mower is actually in really good condition...
I have tried again, following the procedure..still the same..getting a bit frustrated now...I have no issues with ripping it right apart and taking sump off...I just don't want to do this if not necessary...I wish i could find some pictures of the internal workings of the Governor of this engine so i could get a better understanding.
i do too , im sure it will be in manuals though . i dont have a book here that covers quantum and no scanner so i can anyway its just as i do when i need to but never hadto pull one down before yet . maybe a few photo's will help us work it out for you mate . or another member will have a page to show you , sorry i dont have
Just so we can be certain of the exact beastie we're dealing with here, there are a set of 3 numbers which are the key to Briggs engine ID. They are the 'Model, Type and Code', and will be in that order. See if you can post them up, if at all possible.
On this engine, they should be stamped in two places - the inner metal cooling cowl, above the spark plug; and on the heat deflector plate above the muffler. Rust may have obscured the latter lot, though.
I'd say that the Briggs Repair Manual you need is P/No 270962, Repair Manual Single Cylinder L-Head, if as I suspect, this is a 12000 model series side valve engine. There are a few free downloads of it around the Web, or it's available for pay [subscription] in the ODK 'Engine Manuals & Parts List' section.
The function of the governor spring is to hold open the throttle; the centrifugal governor acts against it, and backs off the throttle, as engine revs increase. The older print edition Briggs Repair Manuals had a section at the end, that described this concept very well, with diagrams. That all seems to have gone over to their Training Course Textbooks these days, though...
It is surely possible for the governor internals to fail, as it's a part of the oil slinger, that's driven off the camshaft gear. At least the slinger gear is plastic, and on the Quantums the camshaft gear is too, IIRC.
Cheers, Gadge
"ODK Mods can explain it to you, but they can't understand it for you..."
"Crazy can be medicated, ignorance can be educated - but there is no cure for stupid..."
Just opening this thread back up as I have finally got back to this mower...I have opened the sump up and found the Governor oil slinger to be broken.. Can anyone help me with a part number? and maybe tell me the best place to get one online?
[quote=AVB]Hmmm miss a digit 12H802-3123-B1. And Gadge got it right on the repair manual 270962 [/quote
If you double check the engine number, you will find that AVB has it right, and the manual you want can be found on the Briggs and Stratton website below: -
I can't find an exact IPL for your engine via any of the Briggs websites I use.
But you could always get a quote from the ODK Shop - there is a new parts search facility, that finds your exact engine model.
BTW, you'll need a new crankcase gasket too.
Once you have the part number, it's a matter of doing a Google search on it; e.g. as 'Briggs XXXXXX'.
There are two traps with US internet suppliers. One is that many don't ship outside the US, but you have to dig into their shipping info to find that out. The other issue is that shipping can be very exy; US Postal Service [USPS] is almost always the cheapest option.
It's often easiest to search on eBay US; sellers usually say if they offer international shipping, and have a postage calculator in their ad.
Cheers, Gadge
"ODK Mods can explain it to you, but they can't understand it for you..."
"Crazy can be medicated, ignorance can be educated - but there is no cure for stupid..."
Sorry, I wasn't quick enough to edit the above. Briggs and Stratton require a 6-digit (Alpha/Numeric) Model number, so when you only noted 5 earlier, there was one digit (or letter) missing. Note: Some of the early Model numbers only had 5 digits so, in these cases, you need to add a zero "0" in front to make up the 6th digit to allow a search. You can save and use this link for future engine searches:-
The above search uses the 6-digit model code and the first 4-digits of the Type, then you pick the engine relative to your final code number. In your case, you enter 12H802 in the Model search box and 3123 in the Type search box and press enter. The result will give you two engine variations. These being 12H802-3123-B1 and 12H802-3123-E1. Your engine is the first on the list and you can download the Illustrated Parts List and/or the Operators Manual specific for your engine.
As an extra bit of information, the Engine Code 03060259 is the date and factory of the engine. The date in the first 6 digits in YYMMDD format, being 2nd June 2003, and the last 2 digits are the factory, being Factory 59.
You are correct in the Part number for the Oil Slinger, according to the above link, is 691997. I have searched the ODK Parts Database, as suggested by Gadge, but it is not listed as an item stocked, so have found the part in Australia for $45 plus P&H from [Censored] at:-
Otherwise, eBay seems to be other option. None listed in Australia, but they are listed on our eBay with indicative P&H charges. The Part Number reference appears to be common to a large number of engine variations and models, and being a Genuine Briggs and Stratton part, one would expect the part to remain identical.
Folks, here's another useful site for Briggs parts lists: http://bsintek.basco.com/MDEXResultsPages/default.aspx This one only requires the 6-digit Model Number, but may require looking through a few results pages to find the Type, or one that's close.
AVB had the correct Model/Type number above, with the missing digit.
