New intake manifolds,,,Problems

[mikeyBskunk]

Hey there i purchased new intake manifolds from mikes xs. they have the barbs for carb syncing. Befor i had the original stock ones on and my bike ran and idled fine. with the new ones on it dosnt want to idle and will only run with the choke on... Any suggestions???

Mikey

 

[retiredgentleman]

Several years ago, I also bought manifolds from Mikesxs. I only used them for a short time as they were a very poor fit and allowed a lot of air leakage and lean running. I re- installed my original stock manifolds and no more air leakage.

Parts from Mikesxs are like flipping a coin.................some parts are OK and some are just crap.

My suggestion..............use your original manifolds, or buy from JBM as they have a good reputation for quality.

 

[picker]

It seems you have a vacuum leak with your new ones, Choke just adds more fuel to make up for the extra air coming in.
You can use some wd40 and with the choke on and running confirm it then pull the carbs and manifolds back off. I dont believe there were gaskets on these, just a rubber sealing ridge built into the manifold so if you have paper gaskets take them out.
maybe someone else can verify the no gasket thing but I`m pretty sure there shouldnt be any.

 

[motorkiller31]

just asking the obvious but did you cap off the vacuum ports.

 

[mikeyBskunk]

yes i caped the vacume ports and really no diffrence then with them not caped

 

[5twins]

I have replacements and I use gaskets - but not the thin paper ones that came with the manifolds. I use thick ones, either new O.E.M. or the nice thick ones that come in the complete engine gasket kit. I don't think those thin paper ones included with the new manifolds are any good.

 

[mikeyBskunk]

My new manifolds did not come with gaskets, i put the original,stock ones on

 

[xjwmx]

I don't know what year you have but you could try jbm intake boots. They're probably ok for bs38s but I think they messed up really, really bad by not simply copying the stock boots, at least for bs34s.

And if Mike's boots are unserviceable, you should get your money back. Sue them long distance if you have to. You may never collect but you you can post the judge's verdict here... Everything you buy anywhere automatically comes with an implied warranty saying that it works.

 

[CDNTX650]

JBM manifolds are awesome, i have them for my 34's and they are a really well made piece compared to mikes shitty ones.

 

[xjwmx]

JBM ...i have them for my 34's and they are a really well made piece

What do you do about the vacuum connections?

 

[Grinder]

JBM's, the only way to go. Good parts, good guy.

 

[CDNTX650]

What do you do about the vacuum connections?

edit, JBM no longer drills the plates or installs vacuum barbs, as this weakens the plate and takes too much time
for us to do. Customer must install his own barbs at his own risk.

really gay.

it has them.....you can get them with or without

 

[xjwmx]

^That's what I meant. And putting a barb in "weakens it" and apparently is not recommended. So they should have just copied the stock original and let you use your metal shrouds. If somebody doesn't have the shrouds, then let them be the one to suffer. That's the natural order of things....

 

[mikeyBskunk]

Sooo it sounds like JBM is the way to go but unfortunally they are sold out of the bs38 carb intakes now the waiting game?

 

[xjwmx]

^They aren't sold out of the 34s because they're useless without barbs Even if you just need them for balancing.

 

[CDNTX650]

well i can say my mine are awesome with the barbs. Very well made.