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Thread: 1984 ATC 250R: DG Gold Head Fitment Issue

  1. #1
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    1984 ATC 250R: DG Gold Head Fitment Issue

    For those of you looking to fit a DG sunburst head to the 2nd generation 250R, I thought I would alert you to a fitment problem. I bought a sunburst head a few months back thinking they were compatible with the 1st and 2nd generation R. Wrong. The DG head for the 1st and 2nd generation are different. If you buy a 1st generation head for a 2nd generation R you will run into a pipe interference problem. The frame is narrower on the 2nd generation R and the pipe (including the aftermarket DG) hits the back of the head making it impossible to mount. Thankfully there's a small machine shop near me with a milling machine and he did a great job cutting back a couple of fins (see pictures). DG did something similar from the factory back in the day but I didn't know it until I ran into the problem myself.

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  2. #2
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    Carthage NY 250r rules
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    That's odd I put my 1st gen DG head on my 83 no issues. Im running a Cobra exhaust maybe its smaller where it goes near the head.Sweet r you have there.
    250r rules

  3. #3
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    That's great information to know. I would of assumed they were the same. I just picked up a 2nd gen myself a few weeks ago and always wanted one of these heads. Just gotta find one that isn't priced more than what I paid for the whole bike lol.


  4. #4
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    Quote Originally Posted by atc300r View Post
    That's odd I put my 1st gen DG head on my 83 no issues. Im running a Cobra exhaust maybe its smaller where it goes near the head.Sweet r you have there.
    Yeah, some aftermarket pipes might work. I just know the stock and the DG pipe will not. Below is a picture of the DG second generation head (currently available on ebay). You can see the back edge is cut off at an angle. I didn't learn about this difference until I read an old 3Wheeling article on this website entitled "Bake Off: Aftermarket Cylinders." Unfortunately I can't find it at the moment. It is a good article about the DG head and whether it cools better than other aftermarket heads--and it does. I'll post it if I can find it.

    http://www.ebay.com/itm/DG-Performan...-/131892104389

  5. #5
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    Quote Originally Posted by christph View Post
    Yeah, some aftermarket pipes might work. I just know the stock and the DG pipe will not. Below is a picture of the DG second generation head (currently available on ebay). You can see the back edge is cut off at an angle. I didn't learn about this difference until I read an old 3Wheeling article on this website entitled "Bake Off: Aftermarket Cylinders." Unfortunately I can't find it at the moment. It is a good article about the DG head and whether it cools better than other aftermarket heads--and it does. I'll post it if I can find it.

    http://www.ebay.com/itm/DG-Performan...-/131892104389
    This is sort of a bunny trail/tangential question...why do all the 1st/2nd gen Honda DG heads I look at or work on have the detonation marks on them? A poorer aluminum used to OEM or guys just flogging the crap out of them and not using the right octane? Anyone know?
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  6. #6
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    Quote Originally Posted by yaegerb View Post
    This is sort of a bunny trail/tangential question...why do all the 1st/2nd gen Honda DG heads I look at or work on have the detonation marks on them? A poorer aluminum used to OEM or guys just flogging the crap out of them and not using the right octane? Anyone know?
    Good observation, I see that a lot too. I have two heads now, one for my 82 and one for my 84. My 82 is perfect but my 84 has a few marks. It could be due to a number of things. One, perhaps its the aluminum. I've wondered how they made them. I think it's an extrusion process, i.e., pushing aluminum through a die. Perhaps they had to use softer aluminum. Two, it's a high compression head. The stock head is 24cc and the DG is 22cc. I don't know if many people know this and they run them on pump gas. They are prone to detonation, especially when they heat up. I know mine runs best with a 50/50 mix--half race and half pump gas. Three, they are old and some people have just abused them. They may have run them without a filter.

  7. #7
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    Quote Originally Posted by yaegerb View Post
    This is sort of a bunny trail/tangential question...why do all the 1st/2nd gen Honda DG heads I look at or work on have the detonation marks on them? A poorer aluminum used to OEM or guys just flogging the crap out of them and not using the right octane? Anyone know?
    I always wondered the same thing. But I wasn't experienced enough with rebuilding motors to know that kinda stuff. Honestly it kinda steered me away from them because it just looks like a bad investment if the heads that bad.

  8. #8
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    Glad I am not the only one who has seen this.

    Most porcupine heads that I have used for foolers I have to re-weld and have the heads recut between 19-22 cc's for race applications and 22.5-24 cc's for pump, depending on UCCR.

    I honestly think guys bought these, had no idea what they were doing and like christph stated, ran pump gas....uggghhh....becomes an expensive fix for such an unnecessary issue.
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  9. #9
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    Been waiting for some info on this subject. Attached you will see what I "beleive" to be 2 different types of DG heads. I've had these heads for years now and decided to finally get my 81' Fooler up and running. Plan is to have a "DG" fooler with a pipe as well. The head on the left is what I commonly see on Air foolers and the other one, who knows??? Thought the one on the right would look like the one christph had shaved but it doesn't. I beleive maybe its a Honda CR125 air cooled dirt bike??? don't know. Both heads fit the cylinder studs perfectly. I don't think that the head on the right was shaved, but made that way. Did DG make to styles of heads for the 81' thru 84' ATC 250R's ???? Christph maybe that magizine article could shed some light and if not, maybe the members on here could narrow it down. Click image for larger version. 

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  10. #10
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    Quote Originally Posted by ATC4ever! View Post
    Been waiting for some info on this subject. Attached you will see what I "beleive" to be 2 different types of DG heads. I've had these heads for years now and decided to finally get my 81' Fooler up and running. Plan is to have a "DG" fooler with a pipe as well. The head on the left is what I commonly see on Air foolers and the other one, who knows??? Thought the one on the right would look like the one christph had shaved but it doesn't. I beleive maybe its a Honda CR125 air cooled dirt bike??? don't know. Both heads fit the cylinder studs perfectly. I don't think that the head on the right was shaved, but made that way. Did DG make to styles of heads for the 81' thru 84' ATC 250R's ???? Christph maybe that magizine article could shed some light and if not, maybe the members on here could narrow it down. Click image for larger version. 

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    Yes, DG made two types of heads for the 81-84 Fooler and you have both. The one on the right is for the 1st generation and the one on the left for the 2nd generation. The article I mentioned shows the 2nd generation and it has the triangular cut out just like yours. They did it to clear the pipe. I didn't cut mine like that because it didn't need that much taken off to work with the DG pipe, although it may of needed more for the stock. I also have an 82 R with a DG head and it is like the one on the right--no cut out. It works just fine with no clearance problem. I'll see if I can find that article. It's on this website.

  11. #11
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    Dec 2005
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    Quote Originally Posted by christph View Post
    Yes, DG made two types of heads for the 81-84 Fooler and you have both. The one on the right is for the 1st generation and the one on the left for the 2nd generation. The article I mentioned shows the 2nd generation and it has the triangular cut out just like yours. They did it to clear the pipe. I didn't cut mine like that because it didn't need that much taken off to work with the DG pipe, although it may of needed more for the stock. I also have an 82 R with a DG head and it is like the one on the right--no cut out. It works just fine with no clearance problem. I'll see if I can find that article. It's on this website.
    Good info. I'll defenitly be using the 1gen head for my 81' R. Don't knwo what'll do with the 2nd gen DG head, as I have a big bore 300cc top end on my 84' R. If you can point me in the right direction of that article that's on this wedsite. Thanks!

  12. #12
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    Mar 2013
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    I'd be interested in it but I'm out of state for work for a couple months. Maybe I'll see if you haven't found a use for it by then.

    How'd you make out with the domes on those? As mentioned above it's hard to find a nice one anymore.

  13. #13
    Join Date
    Feb 2011
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    San Marcos Ca.
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    Quote Originally Posted by christph View Post
    For those of you looking to fit a DG sunburst head to the 2nd generation 250R, I thought I would alert you to a fitment problem. I bought a sunburst head a few months back thinking they were compatible with the 1st and 2nd generation R. Wrong. The DG head for the 1st and 2nd generation are different. If you buy a 1st generation head for a 2nd generation R you will run into a pipe interference problem. The frame is narrower on the 2nd generation R and the pipe (including the aftermarket DG) hits the back of the head making it impossible to mount. Thankfully there's a small machine shop near me with a milling machine and he did a great job cutting back a couple of fins (see pictures). DG did something similar from the factory back in the day but I didn't know it until I ran into the problem myself.

    Click image for larger version. 

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    Hey that looks good on your trike. I'm glad that worked out for you.
    * 1970 US90 Red
    * 1978 ATC 90/180 Helm&Son, Bandito /3D springer. ( Spaghetti Winder )
    * 1978 ATC 90/128 Bandito / Ace Williams Springer.
    * 1980 ATC 110/ ? Helm&Son, Dickson Full Suspended
    * 1981 ATC 110 MTC Full Supended
    * 1985 ATC 200s
    *1986 ATC 250R/310 2"+ Westcoast Swinger

    http://www.ebay.com/usr/jwheeler760

  14. #14
    Join Date
    Dec 2005
    Location
    South Carolina
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    Fellas, christph was just talking about the 2 different types of sunburst heads DG made for the 1st and 2nd gen ATC 250R's. Ebay has what I assume is the 2nd gen head (will work on 1st and 2nd gens) on a 82' R motor. Ebay item #152411778055. I always wanted to see how that K&N universal air filter set up worked for the 1st gens. Looks good!

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