what should i use to rebuild top end

surfcali

New Member
Oct 22, 2015
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Hello this is my first post on here. I bought a blaster from a friend a few years ago for my girlfriend to learn to ride and recently we were riding in mammoth and i believe the top end blew out. Was wondering if anyone could make recommendations for how i should rebuild. I want to add power. The bike is not for racing we do mainly desert riding with a few trips to the mountains each year. How big should i bore? And where should i get parts? Recently added a toomie exhaust and jet. Would like to upgrade carb also. I will be ordering the parts and having a mechanic friend do the work. Any thoughts our recommendations would be great.
 
Are you sure it blew ?
Does it kick over ?
Check compression ?
Check for broken reeds and spark ?
Report back with those findings.


Do not bore it any further than needed to get to the next clean bore. The few cc's even @ max bore adds next to no power.
The power is unleashed by porting that cylinder, which most of us use and get great results from
Kenoconnorracing.com.
Well worth the cost of shipping to know its bored and ported to perfection, and rip ! :)
He can supply all parts needed too.

The stock carb will work great with porting that cylinder and the Toomey pipe you already have.

Was it jetted for the Toomey and any other mods it may have ?
(Pipe, Air filter, oil injection delete, ect)
 
Actually no I'm not completely sure it blew. I haven't done a compression test or checked the reeds but the bike starts no problem and idles fine but when u try to accelerate it has no power at all. Like 2mph top speed. Cleaned the carb and checked components and replaced spark plug and brand new uni air filter. Messed around with throttle and air fuel screw for hours to see if either of those was causing problem from New exhaust. No luck. Recently replaced reeds last year. What do you think? It will randomly have power and work fine for a minute or two then no power
 
Actually no I'm not completely sure it blew. I haven't done a compression test or checked the reeds but the bike starts no problem and idles fine but when u try to accelerate it has no power at all. Like 2mph top speed. Cleaned the carb and checked components and replaced spark plug and brand new uni air filter. Messed around with throttle and air fuel screw for hours to see if either of those was causing problem from New exhaust. No luck. Recently replaced reeds last year. What do you think? It will randomly have power and work fine for a minute or two then no power
 
That sounds like a TORS problem, and/or parking brake curcut if 03+ ?
Check the stickied threads at the top of the electrical section for TORS delete for your year, and parking brake (03+) just gets unplugged at the brake lever to delete it.

A cracked or broken Reed could also give those symptoms.

Was the carb jetted for the Toomey and Uni ?
It needs to be, confirmed with plug chops (plug chop instructions in carb section)
On my phone right now and too hard to copy/paste links :(
 
That sounds like a TORS problem, and/or parking brake curcut if 03+ ?
Check the stickied threads at the top of the electrical section for TORS delete for your year, and parking brake (03+) just gets unplugged at the brake lever to delete it.

A cracked or broken Reed could also give those symptoms.

Was the carb jetted for the Toomey and Uni ?
It needs to be, confirmed with plug chops (plug chop instructions in carb section)
On my phone right now and too hard to copy/paste links :(
How can I check my compression?
 
found this quick did not
decide on it's legit'ness but
search this stuff:)

get a comp test at a local auto parts store/slash internet is more un reliable at timesssss
and test it:)
should be at 120psi with throttle held wide open/and kicking till compression stops rising
 
found this quick did not
decide on it's legit'ness but
search this stuff:)

get a comp test at a local auto parts store/slash internet is more un reliable at timesssss
and test it:)
should be at 120psi with throttle held wide open/and kicking till compression stops rising
Where can I get one of those tester things?