Jacked up my 760..

[enzo]

The crank went and took out the case bottom. I had just rebuilt it to and the crank looked O.K.. Now the cylinder(61x) is bored to 85 mm and needs to go to 85.5. Which means it's junk! Can you bore one out that far? Basically a total loss.
:banghead:

[keefer]

Why don't you just resleeve that jug with oversize sleeves and start at 84 or 85. You will have to bore the cases for the big sleeves but at least you will have room for oversizes. Otherwise just resleeve with standard size and go back to 81mm. I thought that the max recommended bore for the 61x was 84.5 even though I have heard of others running them at 85, very thin.

[Matt_E]

Holy cow...you had stock 61x sleeves at 85mm bore??? :bigeyes:

[yamaslut]

how bad is the hole on the cases? ive been looking for stuff to use my new welder on.. :-)

if you're gonna toss the cases, lemme know.

change the crank out.... you know that boat has been sitting for ever too... I got lucky, you might end up like Enzo :frown: :frown: :frown: :frown: :frown:

[FL-cracker]

cool, I never new you could run 85mm pistons in a STOCK 61X. That means for my 62t build I can go 84 mm and still have 2 over bores, those sleeves are thin, but doesnt look to scary. Now I am considering a fresh crank, damn this shiot gets expensive!

[yamaslut]

cool, I never new you could run 85mm pistons in a STOCK 61X. That means for my 62t build I can go 84 mm and still have 2 over bores, those sleeves are thin, but doesnt look to scary. Now I am considering a fresh crank, damn this shiot gets expensive!

it's not recomended

[FL-cracker]

My ski is a 93wb1 the motor was always stock except for 1 season with a limited pipe. Should I put a new crank in to be safe? Ski doesnt have to many hours on it, but has been ridden, and the crank is 13yrs old. thanks

[Matt_E]

cool, I never new you could run 85mm pistons in a STOCK 61X. That means for my 62t build I can go 84 mm and still have 2 over bores, those sleeves are thin, but doesnt look to scary. Now I am considering a fresh crank, damn this shiot gets expensive!


:boggled: No....I wouldn't go there. Many builders recommend you don't go over 84mm with stock 61x sleeves.

[FL-cracker]

Thanks fellas for the input! If you no any one with a good big bore cylinder setup let me know. Do you think dual 46 red tops will run strong with a pump gas ported 83mm piston setup with a 701 35cc domes ADA head? Will it be rliable on pump gas? Glad I found this form, you guys seam to no what your talkin. Thanks!

[FL-cracker]

^^^^^Great Pic. I have been told though that if I run a single carb I run the risk of starving a cylinder, leading to detination, I want to be able to hold her WFO! Should I notice a big power increase going from a stock 61x with limited pipe to a 62t ported with limited pipe+ head? still pump gas. hope all this $ is worth it.

Will the limited pipe still work good for this setup, or is it worth the $ for a Mod chamber?

[FL-cracker]

nevermind...Just got a fresh big sleeve 85.5mm flat top TLR freestyle ported top end with girdled head. extra domes+ pistons+ carbon reeds+ raider gasket to lower compression a lil. 920 shipped! Im stoked!

Should I save some $ and just get another 44 carb to add to the one I got, or get the 46 redtops? This is the motor I was wanting to build!

[WaveDemon]

I have been told though that if I run a single carb I run the risk of starving a cylinder, leading to detination, I want to be able to hold her WFO!

This is a common misconception. your carb is not a fuel injector! your carb meters both air and fuel. If your carb is tuned properly it should never detonate based on not enough fuel now matter how small the carb is or how big the engine is.

as a general rule in all motors with carbs - smaller (and fewer) = better throttle response

[sjetrider]

nevermind...Just got a fresh big sleeve 85.5mm flat top TLR freestyle ported top end with girdled head. extra domes+ pistons+ carbon reeds+ raider gasket to lower compression a lil. 920 shipped! Im stoked!

Should I save some $ and just get another 44 carb to add to the one I got, or get the 46 redtops? This is the motor I was wanting to build!

sounds like you got a deal if bore, pistons, rings and domes are new. I ran same set up w/ twin 44mm carbs, ran great. I upgraded to 48mm full specs. and I love them, but didnt add $800.00 worth of power. I would stick with twin 44mm carbs if you dont want to spend huge $ on full specs.. Limmetted "b" chamber will be fine on this set up, but you could also spend $50.00 at a local welding shop and have 2" cut out of the limmitted chamber and you will have a mod chamber. Thats my suggestion.

[sjetrider]

The crank went and took out the case bottom. I had just rebuilt it to and the crank looked O.K.. Now the cylinder(61x) is bored to 85 mm and needs to go to 85.5. Which means it's junk! Can you bore one out that far? Basically a total loss.
:banghead:

what brand rods were these?

[FL-cracker]

cool! Thanks for everyones input! for about $160 more then what I will have to spend on setting up the dual 44s, I can have the 46 redtops, so I guess the red top 46s it is!

[enzo]

how bad is the hole on the cases? ive been looking for stuff to use my new welder on.. :-)

if you're gonna toss the cases, lemme know.

Not bad. The rod dented the case bottom about a half inch by 2 inches.

However the case bottom is from a 650 motor so might as well replace it.

I took the cheap route a month ago when this motor drove a piston out the bottom of the cases. Should have tossed the lot than. The upper case half has had some serious porting as welll as the cylinder and the set up ran so sweet that I wanted to try and save it.

[enzo]

what brand rods were these?

The rods/crank as well as the sleeves appear to be stock. This motor was in my ski when I bought it a year ago. Its had the crap rode out of it every weekend since than.

[enzo]

Pulling it back out of the trash can right now. Pm me your shipping info.