Top End Porting

[biodave27]

Can you tell from a picture if a cylinder is top end ported? I just bought an 88' Banshee with old school fmf pipes and 34mm PJ's. I ride more woods and hills, there are not really any dunes close. What can I do to regain bottom end?

 

Banshee Pictures

[squish]

yes that is ported. Looks like the sport port templet job.

[biodave27]

what does this mean?

[Leadfoot350]

You will have bottom end with proper jetting.

[biodave27]

Would it help to run a smaller carb? I thought that 34's were kind of big if it's only a mild port and my older pipes.

[yamamama350]

you could always bump the compression up, or go to a 2 in 1 carb system. change gearing , or tire size.all these things will help bottom end. almost looks like drag portin. How hi r the exhaust ports.

Edited October 29, 2004 by yamamama350

[SDD]

The only way to tell what kind of porting you have is to see a port map or know the port durations. Measure the distance from the top of the cylinder to the exhaust port top. Give me this number in MM. Do this for the transfers and the boost port as well. With this info you can tell what the builder was shooting for. You can't tell just by looking into the intake port which has nothing to do with the port timing.

[roosthrower]

looks like someone opened up those intakes a ton. between the size of those intake ports, the 34mm carbs, and with the exhaust duration being unknown, they all decrease bottom end power. do as ssd said and measure from the top of the ports to the top of the cylinder. these #'s should help determine what kinda port job you have after the durations are calculated. give us the #'s, and we'll get the duration for you.

[biodave27]

I'm not very familiar with the different ports, would I have to take the cylinder off or the piston out to measure the exhaust port? Would it be distance from the inside of the top of the exhaust port to the top of the cylinder?

[SDD]

You will need to pull the head off the machine to measure things. The motor is easier to work with if it's on a bench but removing the pipes and gas tank and any other items in the way can work for you. You need to measure the inside of the cylinders. All port roofs should be chamfered a little but you can still get a "close" enough number to get an idea about whats going on.

[Quick350]

Yes, I have seen that same cut a bunch, looks like Rudy Kurtz drag port, and if you have no bottom end its because transfers are to high like most so called " drag port" engines are. Paaathetticc. Trade them cylinders off for some stockers and have them properly cut for what your doing, some sucker will want them maybe on ebay. Oh, and by the way brainy one that thinks that changing the intake windows will not change things....hmmm.....eeeeeeehhhh wrong. Inreasing port windows lowers velocity and increases volume....hmmm, doesnt this hurt your bottom... I think so. Come on fellas, dont give the guys advise if you dont know your butt from a hole in the ground......The only people that get anything from your advise is people like me that giggle at your comments. Look kiddo, call a reputable builder and have them guide you in the right direction and dont take the advise from something you read on the net. Most of these guys are just telling you things they have found themselves somewhere else on another website. I learned the lessen the hardway, and now Im fast

[FIRST BANSHEE]

I know nothing about porting, but I do know your pipes are more for top end and your carbs will decrease your bottom and increaseyour top.For a trail and woods machine you can use stock cylinders and bolt on parts and have the power your looking for.

[squish]

From now on everyone ask quick350 before you do anything to your bike.

[broke]

From now on everyone ask quick350 before you do anything to your bike.

[banshee76179]

I learned the lessen the hardway, and now Im fast

He learned a lesson, how to run his mouth..

 

Watch out fellas he's fast.....

Edited November 1, 2004 by banshee76179