Carb Syncronization on XR2 150 and timing, spark plug Qs.

First time poster, long time lurker. <br /><br />To make a long story short...<br /><br />1988 Astroglass Merc XR2 V-6 150...<br /><br />It started when we pulled it out of the barn, but ran poorly due to carb gumming and gunk, so I removed them and cleaned. It sat with Seamfoam in the tank for 3 years. <br /><br />1.) I've purchased a manual and it states that the only adjustments the carbs have are the float height (other than manually changing out the jets), but the book is a little unclear on carb syncronization. The only cab syncing i've done was on a 90 Kaw Ninja a long time ago, and I had to use a vaccum gauge if i remember right...<br /><br />anyway the manual says something to the effect of just being sure the angle of the butterflys is equal amongst all six of them? that's what i gather from it? am i assuming correct?<br /><br />2.) also, TIMING...<br /><br />I haven't fooled with the engine other than cleaning the carbs, looks like setting the timing on this thing is a little more complicated than an old carbed chevy. <br /><br />doign the things i did (cleaning the carbs), would there be any reason I would need to check it and reset it? <br /><br />one more thing.<br /><br />3)<br />would a hotter plug help a rich idle problem? <br /><br />i replaced the current plugs with a BU8H (factory spec) and the manual says a BU10H will be a hotter plug, but when I searched on the iboat forums, i found a diagram that says the BU10H is actually a colder plug and a BU6H would be hotter??? But, seems they don't exist. I can't find them on NGK's website. <br /><br /> http://www.ngksparkplugs.com/techinfo/spark_plugs/partnumberkey.pdf <br /><br />any ideas? <br /><br />thanks a lot guys. these forums have been very helpful. <br /><br />conn

Re: Carb Syncronization on XR2 150 and timing, spark plug Qs.

anyone??

Re: Carb Syncronization on XR2 150 and timing, spark plug Qs.

free bump.<br />Got a manual? Good place to start.<br />Carb sync/Timing--probably best to take it to a reputable mechanic (Link & Sync). The consequences of bad carb sync include fouled plugs, poor idle, etc. Missing the mark on timing can cost you a new powerhead...$$$$$$$<br /><br />NGK plugs are hotter with lower numbers, colder with higher numbers. I would not go hotter than the standard plug; if you are fouling plugs, it is not the plug's fault. <br /><br />Fresh fuel, maybe a Seafoam job (yeah I know you had Seafom in the tank, but 3 year old gas?)<br /><br />Good luck.

Re: Carb Syncronization on XR2 150 and timing, spark plug Qs.

yeah, i've got a manual, but I don't understand their "sync" instructions. I'll re-read tonight and see what I can come up with. <br /><br />after draining the tank and re-filling with fresh gas, it's still wanting to "load up" at idle from what I can gather. I can't really tell whether it's loading up or starving. The engine will die, and it takes a while to get it started back if it idles for 3-5 minutes. I'm going to try pumping the bulb a few times the next time it starts to die to see if it's starving for fuel. I did go ahead and pick up a "check valve kit" which from what I understand is basically a fuel pump rebuild kit, just to keep handy. <br /><br />i picked up some different plugs from the merc dealer and they are BUHW, which i thought were even colder than the BU8H plugs. they flipped through their stash and seems as though merc issued some kind of recall on using the BUHW plugs in some engines due to excessive fouling and suggested a replacement BU8H. when i try NGK's website, I can't find anything like a BU2H or a BU6H. Seems they don't make them.

Re: Carb Syncronization on XR2 150 and timing, spark plug Qs.

oh yeah, there are BU8H plug in the engine now, with it idling poorly.