Thanks for all the responses. I appreciate and need the help. Anyway, I do not think they were cut at the bottom. At the bottom where the cylinder flange meets the base there is chamfered round edge, if they milled it that point would be a square corner. I am thinking maybe the one cylinder got either ground too far, or was replaced and tried to make it fit. I need to to some more research (price wise) to figure out my next course of action. I really appreciate all the help. I am looking at Devil in a blue dress's last post. I wonder if anyone knows how much a machine job like this would cost. To mill the 2 cylinders to the low one. and $120 for 3 base gaskets. I am unsure if raising the cylinders would work if they were not cut on the bottom. Would this change the timing?
squish question
- Thread starter maxco
- Start date
bluemonster1
LIFE MEMBER ONLY ONCE!!!
try uploading your pics to photobucket and then copy and paste on here.You will get a much larger pic for us to then look at.
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Looking at your pics the cylinders are definitely ported and reworked, they also look to be differnt heigths, likely the base is decked on the center one. I have used your pic and made some notes for you to check all 3 cylinders. You dont need to remove the studs to machine the bottoms of cylinders.
(You cant just remove the studs and deck the tops!!) as you need to relief the edge of the bore and radius it with a grinding stone in a hand peice dremel or foredom tool or youll ruin the nicasil coating in them, it will flake off the side of the cylinder from the cutter grabbing it!!)
Anyways, check it with your machinist straight ruler and use your digital calipers to see from the front cylinder skirt(the large one) and measure from the bottom of your rule laying on the front cylinder skirt, there to the gasket surface, sure looks to my eye the center on is already been cut. Youll just need the other 2 cut to match it thats all. someone has cut the rear cylinder skirt so they are likely uneven if you measure so use the front one.
what i was talking about earlier is you need a big swing on a lathe in order to recut the stock mono head, with you using a peak head you can cut the domes easy enuff but they still all must be the same clearance.
(You cant just remove the studs and deck the tops!!) as you need to relief the edge of the bore and radius it with a grinding stone in a hand peice dremel or foredom tool or youll ruin the nicasil coating in them, it will flake off the side of the cylinder from the cutter grabbing it!!)
Anyways, check it with your machinist straight ruler and use your digital calipers to see from the front cylinder skirt(the large one) and measure from the bottom of your rule laying on the front cylinder skirt, there to the gasket surface, sure looks to my eye the center on is already been cut. Youll just need the other 2 cut to match it thats all. someone has cut the rear cylinder skirt so they are likely uneven if you measure so use the front one.
what i was talking about earlier is you need a big swing on a lathe in order to recut the stock mono head, with you using a peak head you can cut the domes easy enuff but they still all must be the same clearance.
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mrviper700 said:
Listen to Don on this as he is the expert when it comes to engine building, mods ect...he quickly surpasses most of the rest of our knowledge.
checked the dimension
they are as follows from gastek surface (bottom) to cylinder skirt. #1 is 30.24, #2 is 29.03, #3 is 29.43. Wow all over the place. So all were obviously ported. and look to be decked from the bottom? but inconsistently. The guy I bought this off has 4 mountain max machines. maybe he didn't keep track of his parts that well. Or whoever "machined" these was not that into precision. A great quality for a machinist. So I would need to get the bottoms decked the same. MrViper700 how busy are you? Anyway I was reading MrViper 700 post. Thank you by the way. And he said I can machine the cylinder heads. How? I could get it done, but I do not have a milling machine. I have seen techniques of straping 400 sand paper to a flat piece of glass or milled steel, and sanding in a figure 8. Is that what is being implied or did I miss-read?
they are as follows from gastek surface (bottom) to cylinder skirt. #1 is 30.24, #2 is 29.03, #3 is 29.43. Wow all over the place. So all were obviously ported. and look to be decked from the bottom? but inconsistently. The guy I bought this off has 4 mountain max machines. maybe he didn't keep track of his parts that well. Or whoever "machined" these was not that into precision. A great quality for a machinist. So I would need to get the bottoms decked the same. MrViper700 how busy are you? Anyway I was reading MrViper 700 post. Thank you by the way. And he said I can machine the cylinder heads. How? I could get it done, but I do not have a milling machine. I have seen techniques of straping 400 sand paper to a flat piece of glass or milled steel, and sanding in a figure 8. Is that what is being implied or did I miss-read?
pm me your number and I will call you to discuss this engine, can do alot more in 5 mins on the phone then typing 10 post and it will be easier to help diagnose the easiest fix and get it repaired correctly. thanx
Devilin AblueDress!
New member
sideshowBob said:
X2! I can tell you what and where to look for issues but just reading other posts by Mr.Viper he can tell you what SHOULD be done to fix. With any luck he has the time to get you all fixed up!
thanks guys
Sent a PM to MrViper700. I cant wait to hear from him. I just don't know what the best/quickest solution will be. Well anyway I had a few questions still. The base gasket I pulled off my machine was 2 seperate metal layers. This is 1 unit right? It's not in perfect shape. A little wearing around the center cylider. I will need to order more. From what I am hearing possibly many? Next back to the oil question. can anyone tell me what it should look like/feel like in the case if it ig getting the correct amount of oil? Like I said mine seems dry. Now there is oil, a very light film on everything, but really light. It feels barely there. Is this how it should be? Next question. The top of the pistons are dark all over. From what I have read I read this to be too rich with the current set up. I have read MrVipers700 post on what to look for on the piston top. The pictures show nice carbonizing on the crown, cleaner on the edges. Mine are not cleaner on the edges. I would think that means I am running"safe" but maybe too much so. I will try to post. By the way the "marks" on the sides of the piston tops were from the squish tests. Thanks
Sent a PM to MrViper700. I cant wait to hear from him. I just don't know what the best/quickest solution will be. Well anyway I had a few questions still. The base gasket I pulled off my machine was 2 seperate metal layers. This is 1 unit right? It's not in perfect shape. A little wearing around the center cylider. I will need to order more. From what I am hearing possibly many? Next back to the oil question. can anyone tell me what it should look like/feel like in the case if it ig getting the correct amount of oil? Like I said mine seems dry. Now there is oil, a very light film on everything, but really light. It feels barely there. Is this how it should be? Next question. The top of the pistons are dark all over. From what I have read I read this to be too rich with the current set up. I have read MrVipers700 post on what to look for on the piston top. The pictures show nice carbonizing on the crown, cleaner on the edges. Mine are not cleaner on the edges. I would think that means I am running"safe" but maybe too much so. I will try to post. By the way the "marks" on the sides of the piston tops were from the squish tests. ThanksAttachments
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If this were my sled I would be wondering right about now what other "creative" fixes were done to the engine or the sled for the matter and I would contact the previous owner and tell him what you are doing, what you have found and ask why it ended up the way it did and what other things I might find. If you do decide to talk with him first explain that you do not want him to pony up any doe (or maybe you do) to fix things right, you just want the plain truth so that when you do get it all back together you have addressed any/all issues and can have the piece of mind that it is put together right and that the sled will then be a dependable ride. If the previous owner has mountain sleds and rides the mountians, I am sure he will understand the need to know the sled is depenable based on where it will be ridden and the issues that are created if the sled goes down in the back country.
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staggs65
Moderator
actually that means youre lean not rich (on fuel)
got alot to learn
Ok Staggs I don't question anyone, but I have a question. I have been looking at the plugs religiously, and from what I know they look good to me. Faint bit of white just at the edges of the electrode. Cardboard from there to the bend, and oil about 3 rings down. From what I have read I thought that seemed good. Why is that what I have been seeing at the plugs, but lean indication at the cylinder tops? What am I missing? I run 93 octane gas, Yamalube, and ride at about 10,000ft-13,000ft. From all indications I am lucky I didn't burn this machine down.
Ok Staggs I don't question anyone, but I have a question. I have been looking at the plugs religiously, and from what I know they look good to me. Faint bit of white just at the edges of the electrode. Cardboard from there to the bend, and oil about 3 rings down. From what I have read I thought that seemed good. Why is that what I have been seeing at the plugs, but lean indication at the cylinder tops? What am I missing? I run 93 octane gas, Yamalube, and ride at about 10,000ft-13,000ft. From all indications I am lucky I didn't burn this machine down.
Devilin AblueDress!
New member
Alot of guys get confused with the rich/lean battle.For example, If you have perfect fuel to air mixture and crank up oil pump you just made engine lean on fuel because oil displaces gas in fuel mix. Leaking carb boot or crank seal lets way to much air in, Leaning fuel way out. Its a fine confusing line. Your 22mm measurement suggests its a little on the less side, Believe adjustment should be 19-21mm. The higher the measurement= less oil. Adjusting it down to 19mm would give engine more oil. Keep in mind its a good idea to keep track of gas/oil consumption to figure out a rough ratio 40-1,50-1 etc. Performance upgrades (like porting,aftermarket reeds and heads) narrows the margin of error sometimes. If sled has run fine for you for 2 years i would say settings have to be close or you prolly would have already cooked it!
Thank god I am enrolled at Totally Yamaha University
Lots more to learn. Devil in a blue dress, a question. Not questioning you, just asking information. My Clymer manual has oil pump adjustment to be set from 22-24 mm. Is this wrong? Or has real life taught people what the facts are. I just want to set things right, but that can be hard to tell sometimes. Thanks for all the guidance and help everyone.
Lots more to learn. Devil in a blue dress, a question. Not questioning you, just asking information. My Clymer manual has oil pump adjustment to be set from 22-24 mm. Is this wrong? Or has real life taught people what the facts are. I just want to set things right, but that can be hard to tell sometimes. Thanks for all the guidance and help everyone.
bluemonster1
LIFE MEMBER ONLY ONCE!!!
between 22 to 24 may be dangerous to run.You have to ride the sled,measure how much gas and oil you use.You can adjust more or less once you know you are 50:1..to much oil would not harm you anyways..ran my oil cable rich first season that I re built my SRX motor,set at 19mm..no problems.Now I am somewhere between 21 mm and about 48:1 if I remember correctly.It is marked in my journal so I can go back and check.Every change I make on my sled is marked in my journal so I can go back and check .
maxco said:Lots more to learn. Devil in a blue dress, a question. Not questioning you, just asking information. My Clymer manual has oil pump adjustment to be set from 22-24 mm. Is this wrong? Or has real life taught people what the facts are. I just want to set things right, but that can be hard to tell sometimes. Thanks for all the guidance and help everyone.
The PDF version of the '00 Yamaha service manual I have says 20-22. If your jetting is at the ragged edge, going richer on oil could push you over into Mr. Squeakyville as Devil suggests. It's easy to over think this and setting it to 22-24 would be a good baseline. As Blue suggests, once you have it back on the snow document fuel/oil consumption, figure your ratio and adjust from there.
IMO - If you run a quality synthetic and are using straight gasoline going as high as 60-70:1 won't hurt anything but that's debateable especially with today's questionable fuel quality. Also, I'd lose the Clymer manual and pick up a genuine.
More Lessons learned
So MrViper 700 called me last night. Nice guy. Really, and alot of patience. We covered alot. He taught me alot. We discussed options. We are looking at decking the 2 tall cylinders to match the short one. This because the shortest one fits the porting/timing cylinder the best. Then shave the heads to give the machine the proper squish. This is a good solution. The best one I feel, but there were some questions I had in afterthought. One of the things he mentioned was the reason this might fit is because they might not be OEM cylinders. That the decked cylinder hits really well with this piston, but has been shaved quite a bit. Aftermarket run a little different than OEM. I am pretty sure these are Wiseco. So that being said. My follow up question is does any one know how different Wiseco are from OEM, or can give me measurements to verify? I am not made of money here, but I have concerns about building a motor to perfectly fit pistons that might not be the best. Anyone have real experience with Wiseco? Are they good,bad, at least within tolerence? Thanks.
So MrViper 700 called me last night. Nice guy. Really, and alot of patience. We covered alot. He taught me alot. We discussed options. We are looking at decking the 2 tall cylinders to match the short one. This because the shortest one fits the porting/timing cylinder the best. Then shave the heads to give the machine the proper squish. This is a good solution. The best one I feel, but there were some questions I had in afterthought. One of the things he mentioned was the reason this might fit is because they might not be OEM cylinders. That the decked cylinder hits really well with this piston, but has been shaved quite a bit. Aftermarket run a little different than OEM. I am pretty sure these are Wiseco. So that being said. My follow up question is does any one know how different Wiseco are from OEM, or can give me measurements to verify? I am not made of money here, but I have concerns about building a motor to perfectly fit pistons that might not be the best. Anyone have real experience with Wiseco? Are they good,bad, at least within tolerence? Thanks.
bluemonster1
LIFE MEMBER ONLY ONCE!!!
if you become a VIP member here..you then can get a manual free on here.maxco said:
Since you are getting into jetting and oil requirements people will need more info.
Questions:
-confirm this is a red head non power valve 700?
-stock exhaust or tripples?
-if tripple piped...what brand?
-stock airbox?
-what is the lowest elevation you ride at?
-what is the normal temp you ride at?
Current jetting:[carbs will have to be diassembled for this...they need to be cleaned anyway]
-main jet?
-needle clips and washer position[this could vary between cylinders]
-needle jet size?[stamped on tube]
-pilot jets?
-fuel screw setting[on bottom of carbs...carefully count the turns clockwise required to lightyl seat each screw and write it down for reassembly]
There is alot of instructions on the forum on carb cleaning...read lots before you start to disassemble/clean your carbs.
Questions:
-confirm this is a red head non power valve 700?
-stock exhaust or tripples?
-if tripple piped...what brand?
-stock airbox?
-what is the lowest elevation you ride at?
-what is the normal temp you ride at?
Current jetting:[carbs will have to be diassembled for this...they need to be cleaned anyway]
-main jet?
-needle clips and washer position[this could vary between cylinders]
-needle jet size?[stamped on tube]
-pilot jets?
-fuel screw setting[on bottom of carbs...carefully count the turns clockwise required to lightyl seat each screw and write it down for reassembly]
There is alot of instructions on the forum on carb cleaning...read lots before you start to disassemble/clean your carbs.