Main jets!

[jipcee]

Belt sits on the top TC ? ? Sorry im kinda new at this im 17 still learning

I think he is talking about the "secondary" not the drive clutch.
If you ride the sled or jack up the rear in the garage and run the track, after the track comes to a stop the belt should be even with the top of the secondary or even sticking up 1/16 of an inch.
You might also check your center to center distance (center of clutch bolt to center of secondary bolt) I think it is 305mm.
It would help alot if you took apart both carbs and wrote down EXACTLY
what: NEEDLES
MAIN JETS
POWER JETS
PILOTJETS
AND WHAT YOUR PILOT AIR SCREW IS SET TO.
If you decide to take the carbs apart (with the float bowls off) I would spray brake cleaner in ALL the little holes and passages and follow up with compressed air in all the holes and passages.
If putting the needle clip in the top slot helps to eliminate the bog then you are running to rich on the bottom end (Pilot jets or Needle itself)

[tyler440]

you beat me to it, but ill say it anyway... check you center to center, i know it is supposed to be 12 inches i just bolted in the engine for my new '84 lastnight... thats right you heard it here first 41inch wide '84 vmax coming up hehehehehe

ps yes and also clean your carbs very well and tell us what all the jet sizes and settings are i think youll find the center to center is off tho

[Chris]

300 mains
130 powers
270 i think is that it says on the slide needles
i have the piolet needle at 3/4
and i dont know the piolet size
Thanks guys

[jipcee]

300 mains
130 powers
270 i think is that it says on the slide needles
i have the piolet needle at 3/4
and i dont know the piolet size
Thanks guys

First thing I would do is measure center to center like stated above.
If the cen to cen is too short the engine is too close to the secondary and causes the sled to start moving in a much higher gear and could be causing the bog.
Its kinda like trying to start moving your 10 speed in 10th gear.
Main and Power jets are O.K. for now.(They are not causing your bog)
Unfortunately the 2 most important things you do not know the numbers. i.e. NEEDLE and PILOT JETS.
The needle # is easy to get, just remove the top of the carb and remove the needle.
The # will be something like 6DH1 or 6DH10 or 6DH8 something along those lines.
Check your CENTER TO CENTER! 305mm or 12 Inches. Measure accurately.
Let us know what you find.

[srxvmax50]

Chris, I struggled so much back in the days of my SRX youth with getting everthing right. Rebuilding engines and chassis, etc. So, after many driving-driven clutch spring-weights combos settings,and often with custom ground weights, I found myself still floundering off the line. It was very frustrating, ohh. Your rebuilt sled has to be calibrated to YOU. Lighten your sled everywhere you dare, then: your sleds net weight, your weight, and your powerband, thats what you gotta deal with. You maybe should dyno your oem rebuilt engine to find out its powerband, interchange "improvements" and check again, and again. You need to do this if you are serious. If you are using Daycos instead of Yamaha belts, then you need to check your clutch distances against specs, because they will be different. Unload both your clutches clamp them to full wide out throttle and move your engine forwards or back to get the proper defflecction. There is so much to it all,and I mean all, but if you stay at it, its worth it. In a nutshell:MJD

[srxvmax50]

Mr. Jipcee is so right when he suggests writing down carb calibrations, clutch and Torgue Converter settings, etc. as you go thru calibrating your sled to suit your needs. Don't be in too big of a hurry as you interchange all of these components. Write stuff down. Towards the end of the tuning process your well kept notes will serve as subtle reminders to what was good and what was not. Always test fresh engines or carb changes while using hi-octane fuel (saves from burndowns, 'cause it's forgiving) Your instincts, your feel, will let you know how you are coming along. .So watch your TC spring shim preload and spring twist, as it may make you think you are jetted rich as you are trying to come up from the bottom of your power curve. It's not in the jetting, it's in the clutching, many times the secondary,(who would have thunk) and that catches a lot of folks. It's almost like each sled has it's own character. These old Yamahas can be reliable superperformers, it just takes a persons experience and intuition. I would like to help you more, and hopefully I may, BUT.. it's a research project. And fun too. MJD

[Chris]

Hmm i think its defenetly clutching i put my spare belt on that was a little worn and it had much more throttle responce , the 2ndary seems REALY soft , should i try . . . that could cause my bog i think you can adjust the spring on it tho right ?

[tyler440]

please oh please check the center to center distance of your clutches... it should be 12in.... if that is correct then check the offset, that should be 11mm... if all of that checks out then go for reclutching... im begging you hahahaha

[jipcee]

Dam 17 year olds, always have something better to do than what you want them to do.
Meanwhile........Us middle aged men, sit in front of the computer to relax,and try to offer the years of our wisdom to those whom need it, anxiously hopelessly waiting for a response to which we might walk away feeling better about ourselves and say ," I"m glad I helped someone."
Now, Chris, get your ass out in that damn garage and measure than center to center distance like I told you to do last week or I promise the next time I go snowmobiling I will leave at home with your mother.
Ohhhh.................SORRY................I thought I was talking to my 21 year old.
Really, Chris I applaud your efforts.
I wish my 21 year old had have your initiative.
Snowmobiles, motorcycles, computers......"Dad it's broke can you fix it?"

[tyler440]

my sled is only a year younger than me.. hehehhehee and i dont have the 81 srx ne more... thats right im not even "silver" yet... shhhh dont tell ne one hahaha

[Chris]

Hey , I did cheak the center distance last week , it was like 12inch and 1/8 i corected it and still didnt make much of differnce the off set is right too. Im going to try to tighten the 2ndary clutch tonight and see how it goes. Ive worked on many Sleds over the last 7 years so im getting better at it but i cant figure this one out , ive had 15 Sleds , 7 three wheelers 7 dirt bikes and 1 street bike all i have restored , Jus this v max isnt co-operating with me
Thanks Guys

[tyler440]

alright so the center to center is ok... are you positive its the 103-c clutch on it and not a 108-c.... alot guys seemed to like to switch primary clutches... you can tell what clutch it is by reading the clutch... do that for me whaile i screme a different idea hehehe

[Chris]

Hey i think its a stock 102 , it doesnt say any thing on the clutch but it used a Yamaha puller , same as for a ET / EX

[srxvmax50]

Is this the end of this or what? Okay, lets not pull this kids string. Chris! Staightenup and listen, listen to your engine I mean.Okay from to the get-go you got a healthy 535, right? I mean chrome/nicasil/oem pistons, & botomends tight and right,huh? Good. Got just enough fuel thru those cleaned carbs? Lts go from there. the other guys are correct with the clutch spacings as per stock, no doubt. May I add that in this case stock isn't always gospel. If you are using one of todays aftermarket belts then they callout for untillbeforenow new and different distances. Minor, but MAJOR. It's not that complicated but I am gettin tired about writing about this. I'll try to help you tomorrow. Politely signed: MJD

[jipcee]

ive had 15 Sleds , 7 three wheelers 7 dirt bikes and 1 street bike all i have restored , Jus this v max isnt co-operating with me
Thanks Guys

I think I forgot to mention in my last post that I am looking to adopt a child.
Very nice Resume, Chris.
It seems like the clutch and secondary are up to par.
I went back and read your original "bog" post.
It looks like we are back to a carburetor problem.
If you have to move the needle clip into the top grove to get above 5000 rpm, the sled is too rich. When you move the clip up it lowers the needle in the needle jet thus letting LESS fuel enter the venture of the carb.

The homework I would ask you to do is to unscrew the top of the carb and pull out the slide and remove the needle from the slide and write down the # on the needle. This should only take 5 minutes.
Let us know.