Different heads on an SRX engine

rx1jim

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Joined
Feb 17, 2008
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925
Location
Poughquag, NY
I bought an 200 SRX which recently had the engine rebuilt by the former owner. While going over it to store it away for the summer, I noticed two of the heads were the newer version but the third head is from the 98/99 vintage. ( one of the recent posts on this site listed what to look for to identify the engine year). Should I get a 00/02 head and swap it out or not worry about it? I know how it probably got there. The owner had a 780 big bore kit which he was very unhappy with. Brought it to a performance shop and had it restored to the stock configuration and had a trail porting job done. The shop who rebuilt the engine must have used what parts they had to keep the rebuild costs down.
 
You may want to caliper that head to see if it matches the other 2 , it is more than probible it has been cut to match . I am pretty sure that the 8dn-10 are cut 10 or 15 thou more than the 8dn-00 stock from yamaha . Some members here will tell you exactly what it was .
 
Mr. Mopar,

Here is the whole story. I am now the third owner of this SRX. The original owner installed the 780 kit on it. The second owner bought it, rode it for part of the 2007 season and began to hear strange mechanical sounds from the engine. He took the engine out and brought it to a guy who worked for Bender Performance for 10 years. The engine builder determine there was a cracked piston and the second owner then decided to return the engine back to nearly stock. The engine builder used a combination of new parts and used parts to restore the engine to the original configuration plus he trail ported the cylinders. The second owner put $3000 into the engine and clutch work. I bought the sled about a month ago and since our snow was gone, I have not a chance to ride it. The engine definitely sounds plenty healthy. It starts on the first pull no matter what temp. and now matter how long it has been since it last ran. I am now in the process of going through the entire sled and putting everything in top condition: ceramic coating the pipes, rebuilding the rear skid, glass beading the bare aluminum parts, stripping and powder coating any part that has the slightest scratch on it, installing a new 1.25" predator track, etc.. The whole sled is coming apart. It looks like the first owner did some amount of grass drags with the sled based on the the grime I have been cleaning out of the belly pan. It will be betterthan showroom condition by July.
 
Just do a simple squish test and youll know if the heads are all set up the same, it should all be the same squish if the one oddball was cut to match the other 2 heads. Use .080" lead solder and bend it in a "L" shape, remove the sparkplugs and insert the solder thru sparkplug hole, make sure you can "feel" the side of the smooth cylinder wall, while holding the solder above the wrist pin(left and right across the sled) spin the clutch with your other hand and the piston will "squish" the solder, remove the solder and check it with some digital calipers on the end, should all 3 cylinders match if done right.
 


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